lifespan notes (late adulthood) chap 17

older adults are taking multiple medications, which can increase the risks associated with consuming alcohol or other drugs. For example, when combined with tranquilizers or sedatives, alcohol use can impair breathing, produce excessive sedation, and be fatal. Optimization of drug use, especially not overdosing, is a key factor in successful aging. How extensive is substance abuse in older adults?

A national survey found that in 2010 the percentage of individuals who engaged in binge drinking (defned as four or more drinks for women and fve or more drinks for men on one occasion in the past 30 days) declined considerably in middle and late adulthood (Centers for Disease Control and Prevention, 2012) (see Figure 14). However, the frequency of binge drinking in the past 30 days was highest among older adults

excessively long sleep duration also is often an indicator of ...

less effective physical and cognitive functioning (Nutakor & others, 2020). In a recent study, long sleep duration predicted an increase in all-cause mortality in individuals 65 years and older (Beydoun & others, 2017). Research indicates that older adults who slept 10 or more hours a day were more likely to have cardiovascular disease and diabetes (Han & others, 2016; Yang & others, 2016). And in a recent study, older adults who slept 8 to 10 hours or more a night were more likely to have memory recall problems (Low, Wu, & Spira, 2019). In general, it now appears that when older adults sleep less than 7 hours or more than 9 hours a night, their cognitive functioning is harmed. sleep problems of older adults are associated with health problems. Strategies to help older adults sleep better at night include avoiding caffeine, avoiding over-thecounter sleep remedies, staying physically active during the day, staying mentally active, and limiting naps. . In addition, one study of older adults indicated that walking at or above the internationally recommended level of 150 minutes per week predicted a lower likelihood of problems with sleep onset or sleep maintenance four years later. older adults who engaged in a higher level of overall physical activity, leisure-time exercise, and household activity were less likely to have sleep problems

the proportion of individuals at different ages has become very ...

similar. Since the beginning of recorded history, lifespan (the maximum number of years an individual can live), has continued to be approximately 120 to 125 years of age. since the 1900s, improvements in medicine, nutrition, exercise, and lifestyle have increased out life expectancy by an average of 30 years.

Four aspects of nutrition are especially important in older adults:

(1) getting adequate nutrition, (2) avoiding overweight and obesity, (3) deciding whether to restrict calorie intake to improve health and extend life, and (4) determining whether to take specifc vitamin supplements to slow the aging process.

Three topics refect the adaptiveness of the human brain in older adults:

(1) the possibility that the brain might be able to generate new neurons; (2) the role of dendritic growth; and (3) the adaptive potential of delateralization.

Older adults move more slowly than young adults, and this slowing occurs for movements with a wide range of diffculty

. Adequate mobility is an important aspect of maintaining an independent and active lifestyle in late adulthood (Patel & others, 2019). Recent research indicates that obesity contributes to mobility limitations in older adults (Adair, Duazo, & Borja, 2018). The good news is that regular walking decreases the onset of physical disability and reduces functional limitations in older adults (Mullen & others, 2012). For example, a recent study of older adults found that walking a dog regularly was associated with better physical health

Life expectancy also differs for various ethnic groups within the United States and for men and women.

. For example, in 2017 the life expectancy of African Americans (75.3) in the United States was 6.5 years lower than the life expectancy for Latinos (81.8) and 3.2 years lower than for nonLatino Whites (78.5) (Murphy & others, 2018). Latino women had a life expectancy of 84.3 and non-Latino White women had a life expectancy of 81.2, followed by African American women (78.5), non-Latino White men (76.4 years), and African American men (71.9 years)

Okinawa in the East China Sea where individuals live longer than anywhere else in the world.

. In Okinawa, there are 34.7 centenarians for every 100,000 inhabitants, the highest ratio in the world. In comparison, the United States has about 10 centenarians for every 100,000 residents. The life expectancy in Okinawa is 81.2 years (86 for women, 78 for men), also one of the highest in the world.

sexual behavior in older adults, engaging in sexual activity was linked to greater enjoyment of life. Also, in another study, older adults were asked about their motivation for having sex.

. In this study, fve main reasons for having sex were: (1) to maintain their functioning; (2) to feel young again; (3) to feel attractive and desirable; (4) to go from lust to love; and (5) to change from "getting sex" to "giving sex."

Dendritic growth can occur in human adults, possibly even in older adults

. Recall that dendrites are the receiving portion of the neuron. One study compared the brains of adults at various ages (Coleman, 1986). From the forties through the seventies, the growth of dendrites increased. However, among people in their nineties dendritic growth no longer occurred. This dendritic growth might compensate for the possible loss of neurons through the seventies but not during the nineties. Lack of dendritic growth in older adults could be due to a lack of environmental stimulation and activity.

Changes in lateralization may provide one type of adaptation in aging adults

. Recall that lateralization is the specialization of function in one hemisphere of the brain or the other. Using neuroimaging techniques, researchers found that brain activity in the prefrontal cortex is lateralized less in older adults than in younger adults when they are engaging in cognitive tasks (Cabeza, 2002; Esteves & others, 2020). For example, Figure 6 shows that when younger adults are given the task of recognizing words they have previously seen, they process the information primarily in the right hemisphere; in contrast, older adults are more likely to use both hemispheres (Madden & others, 1999). The decrease in lateralization in older adults likely plays a compensatory role in the aging brain (Duda & others, 2019). That is, using both hemispheres may improve the cognitive functioning of older adults

older adults show a greater decline in their sense of smell than in their sense of taste

. Smell and taste decline less in healthy older adults than in their less healthy counterparts. A recent study found that a poorer sense of smell in older adults was associated with increased feelings of depression and loneliness (Sivam & others, 2016). And a recent study of older adults revealed that an inability to smell some odors, especially peppermint, was linked to cognitive decline

Three diseases that can impair the vision of older adults are cataracts, glaucoma, and macular degeneration:

1. Cataracts involve a thickening of the lens of the eye that causes vision to become cloudy and distorted (Zheng & others, 2020). By age 70, approximately 30 percent of individuals experience a partial loss of vision due to cataracts. Initially, cataracts can be treated by glasses; if they worsen, the cloudy lens should be surgically removed and replaced with an artifcial one. lder adults (mean age: 76 years) who had undergone cataract surgery were less likely to develop mild cognitive impairment. diabetes is a risk factor. 2. Glaucoma involves damage to the optic nerve because of the pressure created by a buildup of fuid in the eye (Serbin & others, 2020). Approximately 1 percent of individuals in their seventies and 10 percent of those in their nineties have glaucoma, which can be treated with eye drops. If left untreated, glaucoma can ultimately destroy a person's vision. 3. Macular degeneration involves deterioration of the macula of the retina, which corresponds to the focal center of the visual feld. Individuals with macular degeneration may have relatively normal peripheral vision but be unable to see clearly what is right in front of them

What is responsible for such longevity in Okinawa? Some possible explanations include the following:

1. Diet. Okinawans eat very healthy food, heavy on grains, fsh, and vegetables, light on meat, eggs, and dairy products. This diet actually produces mild caloric restriction (10 to 15 percent). The risk of dying from cancer is far lower among Okinawans than among Japanese and Americans (see Figure 2). About 100,000 Okinawans moved to Brazil during the mid-twentieth century and quickly adopted the eating patterns of their new home, which rely heavily on red meat. The result: The life expectancy of the Brazilian Okinawans is now 17 years lower than Okinawa's 81 years! 2. Low-stress lifestyle. The easygoing lifestyle in Okinawa more closely resembles that of a laid-back South Sea island than that of the high-stress Japanese mainland. 3. Caring community . Okinawans look out for each other and do not isolate or ignore their older adults. If older adults need help, they don't hesitate to ask a neighbor. Such support and caring is likely responsible for Okinawa having the lowest suicide rate among older women in East Asia, a region noted for its high suicide rate among older women. 4. Activity. Many older adults in Okinawa are physically vigorous, engaging in activities such as taking walks and working in their gardens. Many older Okinawans also continue working at their jobs. 5. Spirituality. Many older adults in Okinawa fnd a sense of purpose in spiritual practice. Prayer is commonplace and believed to ease the mind of stress and problems.

Researchers who study exercise and aging have made the following discoveries:

1. Exercise is linked to increased longevity. physically active older adults have an increased likelihood of living longer. middle-aged and older adults, including those with cardiovascular disease and cancer, can gain considerable longevity benefts by becoming more physically active and engaging in at least 150 minutes a week of moderate-intensity physical exercise. Exercise stress testing predicts better for how long they would live than their chronological age. energy expenditure by older adults during exercise that burns up at least 1,000 calories a week was estimated to increase life expectancy by about 30 percent, while burning up 2,000 calories a week in exercise was estimated to increase life expectancy by about 50 percent 2. Exercise is related to prevention of common chronic diseases. Exercise can reduce the risk of developing arthritis, cardiovascular disease, type 2 diabetes, osteoporosis, stroke, and breast cancer. 3. exercise is used as part of the treatment, individuals with these diseases show improvement in symptoms: arthritis, pulmonary disease, congestive heart failure, coronary artery disease, hypertension, type 2 diabetes, obesity, and Alzheimer disease. 4. Exercise improves older adults' cellular functioning. 5. Exercise improves immune system functioning in older adults ( 6. Exercise can optimize body composition and reduce the decline in motor skills as aging occurs 7. Exercise reduces the likelihood that older adults will develop mental health problems and can be effective in the treatment of mental health problems 8. Exercise is linked to improved brain, cognitive, and affective functioning in older adults. Older adults who exercise regularly not only show better brain functioning but also process information more effectively than older adults who are more sedentary

current recommendations for older adults' physical activity are ...

2 hours and 30 minutes of moderate-intensity aerobic activity (brisk walking, for example) per week and musclestrengthening activities on two or more days per week. Exercise helps people to live independent lives with dignity in late adulthood (Morgan & others, 2019). At 80, 90, and even 100 years of age, exercise can help prevent older adults from falling down or even being institutionalized (Kaushal & others, 2019). Being physically ft means being able to do the things you want to do, whether you are young or old.

Nearly 60 percent of deaths among U.S. adults 65 to 74 years are caused by cancer or cardiovascular disease. Cancer recently replaced cardiovascular disease as the leading cause of death in U.S. middle-aged adults. The decline in cardiovascular disease in middle-aged adults has been attributed to improved drugs, decreased rates of smoking, improved diets, and increased exercise.

65- to 74-year-olds, with cancer now the leading cause of death in this age group (U.S. Census Bureau, 2019). However, in the 75-to-84 and 85-and-over age groups, cardiovascular disease is the leading cause of death (U.S. Census Bureau, 2019). As individuals age through the late adult years, the older they are the more likely they are to die of cardiovascular disease rather than cancer.

Late-onset alcoholism is the label used to describe the onset of alcoholism after the age of ...

65. Late-onset alcoholism is often related to loneliness, loss of a spouse, or a disabling condition. Researchers have found a protective effect of moderate alcohol use in older adults (O'Keefe & others, 2014). One study revealed better physical and mental health as well as increased longevity in older adults who drank moderately compared with those who drank heavily or did not drink at all (Rozzini, Ranhoff, & Trabucchi, 2007). Benefts of moderate drinking include better physical wellbeing and mental performance, greater openness to social contacts, and increased ability to assert mastery over one's life. A recent study of older adults found that moderate alcohol consumption was linked to greater volume in the brain's hippocampus. moderate drinking of red wine is linked to better health and increased longevity (Li & others, 2019). Explanations of the benefts of red wine center on its role in lowering stress and reducing the risk of heart disease (Li, Li, & Lin, 2018). Evidence is increasing that a chemical in the skin of red wine grapes—resveratrol—plays a key role in red wine's health benefts (Cheng & others, 2020; Wu & others, 2019). One study found that red wine, but not white, killed several lines of cancer cells (Wallenborg & others, 2009). Scientists are exploring how resveratrol, as well as calorie restriction, increases SIRT 1, an enzyme that is involved in DNA repair and aging

What is the quality of health treatment that older adults in the United States receive?

A study of older adults with health problems revealed that they receive the recommended medical care they need only half the time alternative home and community-based care has decreased the percentage of older adults who live in nursing homes (Walters & others, 2017). Still, as older adults age, their probability of being in a nursing home increases (see Figure 16). The quality of nursing homes and other extendedcare facilities for older adults varies enormously and is a source of ongoing concern (Marshall & Hale, 2018). More than one-third of these facilities are seriously defcient. They fail federally mandated inspections because they do not meet the minimum standards for physicians, pharmacists, and various rehabilitation specialists (occupational and physical therapists). Further concerns focus on the patient's right to privacy, access to medical information, safety, and lifestyle freedom within the individual's range of mental and physical capabilities

Older adults also are less sensitive to pain than are younger adults

Although decreased sensitivity to pain can help older adults cope with disease and injury, it can also mask injuries and illnesses that need to be treated. Also, a recent study found that high levels of pain were linked to memory impairment in older adults. Perception and action are coupled throughout the life span. Driving a car illustrates the coupling of perceptual and motor skills. The decline in perceptual-motor skills in late adulthood makes driving a car diffcult for many older adults (Allen, Beck, & Zanjani, 2019; Chen & others, 2020). Drivers over the age of 65 are involved in more traffc accidents than middle-aged adults because of mistakes such as improper turns, not yielding the right of way, and not obeying traffc signs; their younger counterparts are more likely to have accidents because they are speeding

Latinos live 3.3 years longer than non-Latino Whites despite having lower educational attainment and income levels is called the "Latino Health Paradox" (Atiemo & others, 2019). Why does this discrepancy occur?

Among the proposed reasons are migration patterns, extended family connections, and rates of smoking. In terms of migration patterns, Latino immigrants who stay in the United States tend to be healthier than average, while those who return to their countries of origin tend to be older and less healthy. In terms of extended family connections, Latinos provide more support and interaction to their relatives, resulting in less loneliness for Latinos than for nonLatino Whites (Brill, 2019). And in terms of smoking, Latinos are less likely to smoke than nonLatino Whites. In a recent study supporting the Latino Health Paradox, older adult Latinos reported being healthier than their non-Latino White counterparts

Arthritis and osteoporosis

Arthritis is an infammation of the joints accompanied by pain, stiffness, and movement problems. Arthritis is especially common in older adults (Subedi & others, 2020). This disorder can affect hips, knees, ankles, fngers, and vertebrae. Individuals with arthritis often experience pain and stiffness, as well as problems in moving about and performing routine daily activities. There is no known cure for arthritis. However, the symptoms of arthritis can be reduced by drugs such as aspirin, range-of-motion exercises for the afficted joints, weight reduction, and in extreme cases, replacement of the crippled joint with a prosthesis Normal aging brings some loss of bone tissue, but in some instances loss of bone tissue can become severe (Fougere & Cesari, 2019). Osteoporosis involves an extensive loss of bone tissue. Osteoporosis is the main reason many older adults walk with a marked stoop. Women are especially vulnerable to osteoporosis, which is the leading cause of broken bones in women (Madrasi & others, 2018). Approximately 80 percent of osteoporosis cases in the United States occur in females. It is more common in non-Latina White, thin, and small-framed women. Osteoporosis is related to defciencies in calcium, vitamin D, and estrogen, and to lack of exercise. To prevent osteoporosis, young and middle-aged women should eat foods rich in calcium (such as dairy products, broccoli, turnip greens, and kale), exercise regularly, and avoid smoking (Garcia-Gomariz & others, 2018). However, a recent Swiss study indicated that postmenopausal women consume high amounts of vegetables but insuffcient amounts of calcium-rich foods such as dairy products (Lanyan & others, 2020). Drugs such as Fosamax can be used to reduce the risk of osteoporosis (Curtis & others, 2020). Aging women should also get bone density checks.

The increase in the aging population is predicted to dramatically escalate health-care costs over the foreseeable future.

As older adults live longer, disease management programs will need to be expanded to handle the chronic disorders of older adults. The increasing demand for health services among the expanding population of older adults is likely to bring shortages of many types of health professionals, including geriatric nurses, doctors, and health-care aides.

A considerable proportion of older adults remain sexually active. Sexual activity does decline through the later years of life:

As with middle-aged and younger adults, older adults who did not have a partner were far less likely to be sexually active than those who had a partner. For older adults with a partner who reported not having sex, the main reason was poor health, especially the male partner's physical health. Also, older adults are increasingly using online dating sites. A recent study of 4,000 dating profles online found that older adults were more likely to use frst-person plural pronouns (we, our), not be self-enhancing, focus more on connectedness and relationships with others, describe positive emotions, and use words associated with health than were younger adults when seeking a romantic partnership

A general slowing of function in the brain and spinal cord begins in middle adulthood and accelerates in late adulthood

Both physical coordination and intellectual performance are affected. For example, after age 70 many adults no longer show a knee jerk refex, and by age 90 most refexes are much slower (Spence, 1989). The slowing of the brain can impair the performance of older adults on intelligence tests and various cognitive tasks, especially those that are timed (Lu & others, 2011). For example, a neuroimaging study revealed that older adults were more likely to be characterized by slower processing in the prefrontal cortex during retrieval of information on a cognitive task than were younger adults Historically, as in the research just discussed, much of the focus on links between brain functioning and aging has been on volume of brain structures and regions. Today, increased emphasis is being given to changes in myelination and neural networks (Amoroso & others, 2019; Wen & others, 2020). Recent research indicates that demyelination (a deterioration in the myelin sheath that encases the axons and is associated with information processing) of the brain occurs with aging in older adults

As we age, we become more susceptible to disease or illness (Benetos & others, 2019; Vaish, Patra, & Chhabra, 2020). The majority of adults who are still alive at 80 years of age or older are likely to have some type of impairment

Chronic diseases (those with a slow onset and a long duration) are rare in early adulthood, increase in middle adulthood, and become more common in late adulthood. As shown in Figure 13, arthritis is the most common chronic disorder in late adulthood, followed by hypertension. Older women have a higher incidence of arthritis and hypertension and are more likely to have visual problems, but are less likely to have hearing problems, than older men are. Although adults over the age of 65 often have a physical impairment, many of them can still carry on their everyday activities or work. Chronic conditions associated with the greatest limitations on work are heart conditions (52 percent), diabetes (34 percent), asthma (27 percent), and arthritis (27 percent). Low income is strongly related to health problems in late adulthood (Elfassy & others, 2019). Approximately three times as many poor as non-poor older adults report that their activities are limited by chronic disorders.

there are individual differences in how the brain changes in older adults

Consider highly successful business executive T. Boone Pickens, who continued to lead a very active lifestyle at age 85, regularly exercising and engaging in cognitively complex work. Pickens underwent an fMRI in cognitive neuroscientist Denise Park's laboratory, during which he was presented with various cognitive tasks. Instead of both hemispheres being active, his left hemisphere was dominant, just as it is for most younger adults.

Exercise also beneftted frail elderly adults in another study

Decreased walking speed in older adults is associated with limited mobility, less community participation, greater cognitive decline, and increased risk of falls. A recent study of older women found that on average a reduction in walking speed occurred at about 71 years of age. The risk of falling in older adults also increases with age and is greater for women than for men. walking was more effective than balance training in reducing falls in older adults.

Cellular clock theory is Leonard Hayflick's (1977) theory that cells can divide a maximum of about 75 to 80 times, and that as we age our cells become less capable of dividing. Hayflick found that cells extracted from adults in their fifties to seventies divided fewer than 75 to 80 times. Based on the ways cells divide, Hayflick places the upper limit of the human life-span potential at about 120 to 125 years of age. In the last decade, scientists have tried to fill a gap in cellular clock theory. Hayflick did not know why cells die. The answer may lie at the tips of chromosomes, at telomeres, which are DNA sequences that cap chromosomes

Each time a cell divides, the telomeres become shorter. After about 70 or 80 replications, the telomeres are dramatically shortened, and the cell no longer can reproduce. Research indicates that telomere shortening does play a role in aging. one study revealed that healthy centenarians had longer telomeres than unhealthy centenarians. a recent study confirmed that shorter telomere length was linked to Alzheimer disease. And a recent research review concluded that lifestyle modifications involving exercise and diet show encouraging results for delaying telomere shortening Injecting the enzyme telomerase into human cells grown in the laboratory has been found to substantially extend the life of the cells beyond the approximately 70 to 80 normal cell divisions (Harrison, 2012). However, telomerase is present in approximately 85 to 90 percent of cancerous cells and thus may not promote healthy life extension of cells

The aging brain also has remarkable adaptive capabilities

Even in late adulthood, the brain loses only a portion of its ability to function, and the activities older adults engage in can infuence the brain's development (Ji & others, 2019). For example, in one fMRI study, higher levels of aerobic ftness were linked with greater volume in the hippocampus, which translates to better memory (Erickson & others, 2009). Also, a recent study found that a higher level of aerobic ftness embedded in a health promotion program for older adults was associated with higher cortical and hippocampal volumes

more in depth about benefits of exercise on older adults

Exercise improves older adults' cellular functioning.(Researchers increasingly are finding that exercise improves cellular functioning in older adults. For example, researchers recently have discovered that aerobic exercise is linked to greater telomere length in older adults) Exercise improves immune system functioning in older adults (Duggal & others, 2019). Exercise can optimize body composition and reduce the decline in motor skills as aging occurs. Exercise can increase muscle mass and bone mass, improve balance and reduce falls, as well as decrease bone fragility (Fougere & Cesari, 2019; O'Connell, Coppinger, & McCarthy, 2020). Exercise reduces the likelihood that older adults will develop mental health problems and can be effective in the treatment of mental health problems (Sexton & Taylor, 2019). For example, a recent meta-analysis concluded that moderate to vigorous physical exercise was effective in reducing depressive symptoms in older adults with a mean age of 82 years (Klil-Drori & others, 2020). Exercise is linked to improved brain, cognitive, and affective functioning in older adults. Older adults who exercise regularly not only show better brain functioning but also process information more effectively than older adults who are more sedentary

several studies that have found a link between being overweight and living longer, the majority of studies have revealed that being overweight is a risk factor for an earlier death

For example, in a recent large-scale study, obesity was associated with shorter longevity and increased risk of death due to cardiovascular disease compared with normal-weight individuals (Khan & others, 2018). In another recent large-scale study, obesity, as well as high body mass index (BMI) and waist circumference, were linked to earlier death Obesity also is linked to the acceleration of diseases in many older adults (Katsiki & others, 2019; Noale, Limongi, & Maggi, 2020). However, although the link between obesity and disease is present in older adults, the link is weaker than it is for young and middle-aged adults (Kalish, 2016). Researchers also consistently fnd that when individuals are overweight and ft, they have a much better health profle and greater longevity than those who are overweight and not ft (Sardinha & others, 2016). Some researchers now conclude that inactivity and low cardiorespiratory ftness are greater threats to health and longevity than being overweight

A large-scale study of individuals from 57 to 85 years of age revealed that sexual activity, a goodquality sexual life, and interest in sex were positively related to health in middle and late adulthood. Also in this study, these aspects of sexuality were higher for aging men than aging women, and this gap widened with age.

Further, sexually active life expectancy was longer for men than women, but men lost more years of sexually active life due to poor health than women did. As indicated in Figure 11, sexual activity with a partner declined from the last part of middle adulthood through late adulthood, with a lower rate of sexual activity with a partner for women than men. Indeed, a challenge for a sexually interested older woman is fnding a partner. At 70 years of age, approximately 70 percent of women don't have a partner compared with only about 35 percent of men. Many older women's husbands have died, and many older men are in relationships with younger women.

How does the United States fare in life expectancy, compared with other countries around the world?

In 2018, Monaco had the highest estimated life expectancy at birth (89.4 years), followed by Japan, Singapore, and Macau (a region of China near Hong Kong) (85 years) (Central Intelligence Agency, 2015). Of 224 countries surveyed, the United States ranked 53rd at 78.6 years. The lowest estimated life expectancy in 2015 occurred in the African countries of South Africa (50.6 years), Chad (51), and Namibia (51). Differences in life expectancies across countries refect factors such as health conditions and medical care throughout the life span.

What outcomes occur when older adults have dual sensory loss in vision and hearing?

In a recent study of 65- to 85-year-olds, dual sensory loss in vision and hearing was linked to reduced social participation and less social support, as well as increased loneliness (Mick & others, 2018). In another recent study, this type of dual sensory loss in older adults (mean age of 82 years) involved greater functional limitations, increased loneliness, cognitive decline, and depressive symptoms. Most older adults lose some of their sense of taste or smell, or both (Churnin & others, 2019). A recent national study of community-dwelling older adults revealed that 74 percent had impaired taste and 22 percent had impaired smell (Correia & others, 2016). These losses often begin around 60 years of age (Hawkes, 2006). A majority of individuals age 80 and older experience a signifcant reduction in smell

declining visual acuity, color vision, and depth perception are associated with aging.

In late adulthood, the decline in vision that began for most adults in early or middle adulthood becomes more pronounced (Moreno-Cugnon & others, 2018). Visual processing of information declines in older adults (Ebaid & Crewther, 2019). Night driving is especially diffcult, to some extent because of diminishing sensitivity to contrasts and reduced tolerance for glare (Allen, Beck, & Zanjani, 2019). Dark adaptation is slower—that is, older individuals take longer to recover their vision when going from a well-lighted room to semidarkness. The area of the visual feld becomes smaller, a change suggesting that the intensity of a stimulus in the peripheral area of the visual feld needs to be increased if the stimulus is to be seen. Events taking place away from the center of the visual feld might not be detected.

Chinese Longitudinal Healthy Longevity Survey, which includes older adults, some of whom are centenarians.

In one investigation involving this sample, Chinese centenarians showed better coping and adjustment (greater personal tenacity, optimism, coping with negative moods, secure relationships, and personal control) than their Chinese counterparts in their nineties, eighties, or seventies (Zeng & Shen, 2010). In this study, 94- to 98- year-olds with better resilience had a 43 percent higher likelihood of becoming a centenarian than their same-aged counterparts who were less resilient. In a Chinese Longitudinal Healthy Longevity survey, a higher level of education was linked to greater longevity (Luo, Zhang, & Gu, 2015). And in a recent study with this sample, severe loneliness at prior assessment points predicted poorer cognitive function in subsequent assessments

Various drugs, a healthy diet, and exercise can reduce the risk of cardiovascular disease in many older adults

In one study of older adults, a faster exercise walking pace, not smoking, modest alcohol intake, and avoiding obesity were associated with a lower risk of heart failure (Del Gobbo & others, 2015). Another study revealed that diminished exercise capacity and lack of walking were the best predictors of earlier death in older adults with heart problems In the respiratory system, lung capacity drops 40 percent between the ages of 20 and 80, even when disease is not present (Fozard, 1992). Lungs lose elasticity, the chest shrinks, and the diaphragm weakens (Lalley, 2013). The good news, though, is that older adults can improve lung functioning with diaphragm-strengthening exercises. Severe impairments in lung functioning and death can result from smoking

many older adults do not engage in any exercise.

In the United States, physical inactivity increases with age. By age 75, about one in three men and one in two women engage in no physical exercise (Centers for Disease Control and Prevention, 2020). Possible explanations of older adults' reduction in exercise compared with middle-aged adults focus on such factors as chronic illnesses and life crises (a spouse's death, for example), that disrupt exercise schedules, embarrassment at being around others who are in better shape (especially if they haven't exercised much earlier in life), and the "why bother?" factor (not believing that exercise will improve their lives much).

sex difference in longevity also is infuenced by biological factors

In virtually all species, females outlive males. Women have more resistance to infections and degenerative diseases (Pan & Chang, 2012). For example, the female's estrogen production helps to protect her from arteriosclerosis (hardening of the arteries) (Valera & others, 2015). And the additional X chromosome that women carry in comparison with men may be associated with the production of more antibodies to fght off disease. The sex difference in mortality is still present but less pronounced than in the past. Among various groups, the longest average longevity in the United States belongs to Seventh Day Adventists, who have a life expectancy of 88 years. One reason for their longevity is that their religious practices include positive lifestyle choices such as a vegetarian diet.

Unintended injuries are the eighth leading cause of death among older adults

Injuries resulting from a fall at home or a traffc accident in which an older adult is a driver or an older pedestrian is hit by a vehicle are common. Falls are the leading cause of injury deaths among adults who are 65 years and older

Ethnicity is linked with the death rates of older adults (U.S. Census Bureau, 2019). Among ethnic groups in the United States, African Americans have high death rates for stroke, heart disease, lung cancer, and female breast cancer.

Latinos have low death rates for these diseases. In the last decade, death rates for most diseases in African Americans, Latinos, and Asian Americans have decreased. However, death rates for most diseases remain high for African Americans (U.S. Census Bureau, 2019).

New England Centenarian Study

Many people expect that "the older you get, the sicker you get." However, according to the NECS, this is not true for a majority of centenarians. The researchers have found that chronic high mortality diseases are markedly delayed for many years in centenarians, with many not experiencing disability until near the end of their lives. A NECS study of centenarians from 100 to 119 years of age found that the older the age group (110 to 119— referred to as supercentenarians—compared with 100 to 104, for example), the later the onset of diseases such as cancer and cardiovascular disease, as well as functional decline (Andersen & others, 2012). Perls refers to this process of staving off high-mortality chronic diseases until much later ages than usual as the compression of morbidity. Among the factors in the NECS that are associated with living to be 100 are longevity genes and the ability to cope effectively with stress. The researchers also have discovered a strong genetic component of living to be 100 that consists of many genetic links that each have modest effects but as a group can have a strong infuence These genes play roles in Alzheimer disease, diabetes, cardiovascular disease, cancer, and various biological processes. Other characteristics of centenarians in the New England Centenarian Study include the following: few of the centenarians are obese, habitual smoking is rare, and only a small percentage (less than 15 percent) have had signifcant changes in their thinking skills (disproving the belief that most centenarians are likely to develop Alzheimer disease)

Cardiovascular disorders increase in late adulthood

More than 70 percent of older adults who have a heart attack or stroke have preexisting hypertension. Today, most experts on aging recommend that consistent blood pressures above 120/80 should be treated to reduce the risk of heart attack, stroke, or kidney disease. A rise in blood pressure with age can be linked to illness, obesity, stiffening of blood vessels, stress, or lack of exercise (Cheng & others, 2017). The longer any of these factors persist, the higher the individual's blood pressure gets.

The physical decline that accompanies aging usually occurs slowly, and sometimes lost function can even be restored. How does the brain change during late adulthood? Does it retain plasticity?

On average, the brain loses 5 to 10 percent of its weight between the ages of 20 and 90. Brain volume also decreases. a decrease in total brain volume and volume in key brain structures such as the frontal lobes and hippocampus from 22 to 88 years of age (Sherwood & others, 2011). Another study found that the volume of the brain was 15 percent less in older adults than in younger adults (Shan & others, 2005). Recent analyses concluded that in healthy aging the decrease in brain volume is due mainly to shrinkage of neurons, lower numbers of synapses, reduced length and complexity of axons, and reduced tree-like branching in dendrites, but only to a minor extent attributable to neuron loss Also, a recent study of older adults revealed that declines in memory functioning were linked to lower gray matter volume (which contains most of the brain's neuronal cell bodies) in the temporal lobe and hippocampus (Schneider & others, 2019). Of course, brain volume loss occurs in individuals with disorders such as Alzheimer disease (Adduru & others, 2020; Krashia, Nobili, & D'Amelio, 2019). Further, one study found that global brain volume predicted mortality in a large population of stroke-free community-dwelling adults

Eating a healthy, balanced diet and taking appropriate vitamins help older adults maintain their health

One change in eating behavior that can occur in older adults is a decrease in snacking between meals, which contributes to harmful weight loss, especially in women. Among the strategies for increasing weight gain in these women are the use of taste enhancers and calorie supplements between meals.

Changes in touch and pain sensitivity are also associated with aging

One study found that with aging, individuals could detect touch less in the lower extremities (ankles, knees, and so on) than in the upper extremities (wrists, shoulders, and so on). For most older adults, a decline in touch sensitivity is not problematic (Hoyer & Roodin, 2009). And one study revealed that older adults who are blind retain a high level of touch sensitivity, which likely is linked to their use of active touch in their daily lives.

studies about macular degeneration

One study revealed that cigarette smoking contributes to macular degeneration (Schmidt & others, 2006). If the disease is detected early, it can be treated with laser surgery. . However, macular degeneration is diffcult to treat and thus is a leading cause of blindness in older adults (Zhu & others, 2019). Also, there is increased interest in using stem-cellbased therapy for macular degeneration. The decline in vision and hearing is much greater in individuals 75 years and older than in individuals 65 to 74 years of age

Do underweight women and men live longer?

One study revealed that women who were 20 pounds or more underweight lived longer even after controlling for smoking, hypertension, alcohol intake, and other factors (Wandell, Carlsson, & Theobald, 2009). In this study, underweight men did not live longer when various factors were controlled. The research fndings on the effects of calorie restriction in humans are mixed (Dorling, Martin, & Redman, 2020; Locher & others, 2014). Thus, an appropriate conclusion at this time is that further research is needed to defnitively determine whether calorie restriction increases longevity, especially in humans.

In the absence of two circumstances—disease and the belief that old people are or should be asexual—sexuality can be lifelong (Hyde & DeLamater, 2020). Aging, however, does induce some changes in human sexual performance, more so in males

Orgasm becomes less frequent in males with age, occurring in every second to third attempt rather than every time. More direct stimulation usually is needed to produce an erection. From 65 to 80 years of age, approximately one out of four men have serious problems getting and/or keeping erections, and after 80 years of age the percentage rises to one out of two men (Butler & Lewis, 2002). However, with recent advances in erectile dysfunction medications such as Viagra, an increasing number of older men, especially the young-old, are able to have an erection. Also, recent research suggests that declining levels of serum testosterone, which is linked to erectile dysfunction, can be treated with testosterone replacement therapy to improve sexual functioning in males

changes in physical appearance that began occurring during middle age become more pronounced. Wrinkles and age spots are the most noticeable changes. We also become shorter as we get older. Both men and women become shorter in late adulthood because of bone loss in their vertebrae

Our weight usually drops after we reach 60 years of age. This likely occurs because of muscle loss, which also gives our bodies a "sagging" look (Evans, 2010). Figure 7 shows the declining percentage of muscle and bone from age 25 to age 75, and the corresponding increase in the percentage of fat. One study found that long-term aerobic exercise was linked with greater muscle strength in 65- to 86-year-olds.

there are some signifcant differences between adults in their sixties or seventies and adults who are 85 and older.

Paul Baltes and his colleagues (Baltes, 2003; Scheibe, Freund, & Baltes, 2007) argue that the oldest-old (85 and over) face a number of problems, including sizable losses in cognitive potential and ability to learn; an increase in chronic stress; a substantial prevalence of physical and mental disabilities; high levels of frailty; increased loneliness; and the diffculty of dying with dignity at older ages. Compared with the oldest-old, the young-old have a substantial potential for physical and cognitive ftness, higher levels of emotional well-being, and more effective strategies for mastering the gains and losses of old age. The oldest-old today are mostly female, and the majority of these women are widowed and live alone if they are not institutionalized. The majority also are hospitalized at some time in the last years of life, and the majority die alone in a hospital or institution. Their needs, capacities, and resources are often different from those of older adults in their sixties and seventies Despite the negative portrait of the oldest-old by Baltes and his colleagues, they are a heterogeneous, diversifed group. In the New England Centenarian Study, 15 percent of the individuals 100 years and older were living independently at home, 35 percent with family members or in assisted living, and 50 percent in nursing homes A signifcant number of the oldest-old have cognitive impairments, but many do not (Nikitin & Freund, 2019). Almost one-fourth of the oldest-old are institutionalized, and many report some limitation of activity or diffculties in caring for themselves. However, more than three-fourths are not institutionalized. The majority of older adults aged 80 and over continue to live in the community. More than one-third of people who are 80-plus and live in the community report that their health is excellent or good; 40 percent say that they have no activity limitations

Aging has also been linked to reduced synaptic functioning and decreased production of some neurotransmitters, including acetylcholine, dopamine, and gamma-aminobutyric acid (GABA)

Reductions in acetylcholine have been linked to small declines in memory functioning and to the severe memory loss associated with Alzheimer disease, which will be further discussed in the chapter on "Cognitive Development in Late Adulthood" (Benfante & others, 2020; Utkin, 2019). Normal age-related reductions in dopamine may cause problems in planning and carrying out motor activities (Latt & others, 2019). Severe reductions in the production of dopamine have been linked with age-related diseases characterized by a loss of motor control, such as Parkinson disease (Armstrong & Okun, 2020). GABA helps to control the preciseness of the signal sent from one neuron to another, decreasing "noise," and its production decreases with aging

Some studies have shown that calorie restriction in laboratory animals (such as rats and roundworms) can increase the animals' longevity

Research indicates that calorie restriction slows RNA decline during the aging process (Yamada & others, 2020). And researchers have found that chronic problems with the cardiovascular system, kidneys, and liver appear at a later age when calories are restricted (Hegab & others, 2019). In addition, research indicates that calorie restriction may provide neuroprotection for an aging central nervous system (White & others, 2017). One study found that calorie restriction maintained more youthful functioning in the hippocampus, which is an important brain structure for memory

Can the brains of adults, even aging adults, generate new neurons?

Researchers have found that neurogenesis, the generation of new neurons, does occur in lower mammalian species, such as mice (Jain & others, 2019). Also, research indicates that exercise and an enriched, complex environment can generate new brain cells in rats and mice, and that stress reduces the survival rate of these new cells. It also is now accepted that neurogenesis can occur in human adults (Berdugo-Vega & others, 2020). However, researchers have documented neurogenesis in only two brain regions: the hippocampus (Snyder & Drew, 2020) and the olfactory bulb (Durante & others, 2020), which is involved in smell. Researchers currently are studying factors that might inhibit or promote neurogenesis, including various drugs, stress, and exercise (Kempermann, 2019). They also are exploring whether grafting of neural stem cells to various regions of the brain, such as the hippocampus, might increase neurogenesis (Tsutsui, 2020). Research attention also is being directed to the possible role neurogenesis might play in slowing the impairment caused by neurodegenerative diseases such as Alzheimer disease, Parkinson disease, and Huntington disease

more about exercise

Setting exercise goals and then carrying out an exercise plan are important not only in young adults but older adults as well. For example, a study of elderly women revealed that those who had set exercise-related personal goals were four times more likely to report high exercise activity eight years later. Gerontologists increasingly recommend strength training in addition to aerobic activity and stretching for older adults (Naczk, Marszalek, & Naczk, 2020). The average person's lean body mass declines with age—about 6.6 pounds of lean muscle are lost each decade during the adult years. The rate of loss accelerates after age 45. Resistance exercises can preserve and possibly increase muscle mass in older adults.

Sirtuin Theory

Sirtuins are a family of proteins that have been linked to longevity, regulation of mitochondria functioning in energy, possible benefts of calorie restriction, stress resistance, and lower rates of diabetes, Alzheimer disease, Parkinson disease, cardiovascular disease, and cancer one of the sirtuins, SIRT 1, that has been connected to DNA repair and aging.

In 2018, the overall life expectancy for U.S. women was 81.2 years of age, and for men it was 76.2 years of age (Xu & others, 2020). Beginning in their mid-thirties, women outnumber men; this gap widens during the remainder of the adult years. Why can women expect to live longer than men?

Social factors such as health attitudes, habits, lifestyles, and occupation are probably important. Men are more likely than women to die from most of the leading causes of death in the United States, including cancer of the respiratory system, motor vehicle accidents, cirrhosis of the liver, emphysema, and heart disease (Alfredsson & others, 2018). These causes of death are associated with lifestyle. For example, the sex difference in deaths due to lung cancer and emphysema occurs because men are heavier smokers than women. However, women are more likely than men to die from some disorders such as Alzheimer disease and some aspects of cardiovascular disease, such as hypertension-related problems

Genetic/ Cellular theories

Some experts believe that aging is best explained by cellular maintenance requirements and evolutionary constraints (Vanhaelen, 2015). In recent decades, there has been a signifcant increase in research on genetic and cellular processes involved in aging (Entringer & Epel, 2020). Five such advances involve telomeres, free radicals, mitochondria, sirtuins, and the mTOR pathway.

The mTOR pathway is a cellular pathway that involves the regulation of growth and metabolism.

TOR stands for "target of rapamycin," and in mammals it is called mTOR. Rapamycin is a naturally derived antibiotic and immune system suppressant/modulator that was discovered in the 1960s on Easter Island. It has been commonly used and is FDA approved for preventing rejection of transplanted organs and bone marrow. Recently, proposals have been made that the mTOR pathway plays a central role in the life of cells, acting as a cellular router for growth, protein production/metabolism, and stem cell functioning (Jin & others, 2019; Lee & others, 2020). Some scientists also argue that the pathway is linked to longevity, the successful outcomes of calorie restriction, and reducing cognitive decline, and that it plays a role in a number of diseases, including cancer, cardiovascular disease, and Alzheimer disease (Dimri & Satyanarayana, 2020; Rostamzadeh & others, 2019). The rapamycin drug has not been approved as an anti-aging drug and has some serious side effects, including increased risk of infection and lymphoma, a deadly cancer. Some critics argue that scientifc support has not been found for the role of sirtuins and the mTOR pathway in the aging process in humans

Some areas of the brain shrink more than others.

The prefrontal cortex is one area that shrinks the most with aging, and recent research has linked this shrinkage with decreased working memory and slower motor behavior in older adults (Hoyer, 2015). The sensory regions of the brain—such as the primary visual cortex, primary motor cortex, and somatosensory cortex—are less vulnerable to the aging process

How much sleep should older adults get?

The National Sleep Foundation (2020) recommends that they get 7 to 8 hours a night. However, 5 percent or more of older adults complain of having diffculty sleeping, which can have detrimental effects on their lives (Farajinia & others, 2014). In an analysis of sleep patterns from 20 to 90 years of age, total sleep decreased about 8 minutes per decade for males and about 10 minutes per decade for females as they got older (Dorffner, Vitr, & Anderer, 2015). Also in this study, as individuals aged, they engaged in more light sleep and less deep sleep. Researchers also have found that older adults' sleep is more easily disrupted than that of younger adults (it takes longer for older adults to fall asleep initially, they wake up more often during the night, and they have greater diffculty going back to sleep) (McRae & others, 2016). Further, the signifcant reduction in deep sleep in older adults is more likely to occur in men than women (Redline & others, 2004). And in a recent study, older adults who slept 6 hours or less per day were more likely to have fair or poor health Sleep factors are linked to many aspects of older adults' lives (Bernstein, DeVito, & Calamia, 2019; Kaur & others, 2020). Poor sleep is a risk factor for falls, obesity, a lower level of cognitive functioning, and earlier death (Kohn & others, 2020; J. H. Liu & others, 2020; Winer & others, 2019). Research indicates that improving older adults' sleep through behavioral and pharmaceutical treatments may enhance their cognitive skills (Dzierzewski, Dautovich, & Ravyts, 2018). Further, one study found poor quality of sleep in individuals with mild cognitive impairment, which in some cases is a precursor for Alzheimer disease (Hita-Yanez, Atienza, & Cantero, 2013). In another study, sleep duration of more than seven hours per night in older adults was linked to longer telomere length, which was similar to the telomere length of middle-aged adults (Cribbet & others, 2014). And one study revealed that even just one night of partial sleep deprivation activated DNA damage

Why is life expectancy for the United States predicted to increase so much more slowly than South Korea?

The United States has the highest child and maternal mortality rates, homicide rate, and body-mass index of high-income countries in the world. In South Korea, delayed onset of chronic diseases is occurring and children's nutrition is improving. South Korea also has a low rate of obesity, and blood pressure is not as high as it is in most countries.

number of centenarians (individuals 100 years and older) is increasing at a rate of approximately 7 percent each year

The United States has the most centenarians, followed by Japan, China, and England/Wales (Goodman, 2019). The label supercentenarian is now being applied to individuals who live to be 110. Statistics are somewhat sketchy about how many people are currently alive at 110 years and older in the United States and in the world, although it is agreed that it is a small number and also that the number has been increasing in the last decade. Three major studies of centenarians are the New England Centenarian Study, the Georgia Centenarian Study, and the Chinese Longitudinal Healthy Longevity Survey.

Despite the decline in the percentage of individuals who engage in binge drinking in late adulthood, the Substance Abuse and Mental Health Services Administration (2003) has identifed substance abuse among older adults as an "invisible epidemic" in the United States.

The belief is that substance abuse often goes undetected in older adults, and there is concern about older adults who abuse not only illicit drugs but prescription drugs as well (Petrovic & others, 2019). Too often, screening questionnaires are not appropriate for older adults, and the consequences of alcohol abuse—such as depression, inadequate nutrition, congestive heart failure, and frequent falls—may erroneously be attributed to other medical or psychological conditions (Hoyer & Roodin, 2009). Because of the dramatic increase in the number of older adults anticipated over the twentyfrst century, substance abuse is likely to characterize an increasing number of older adults.

A second microbiological theory of aging is free-radical theory, which states that people age because when cells metabolize energy, the by-products include unstable oxygen molecules known as free radicals.

The free radicals ricochet around the cells, damaging DNA and other cellular structures. The damage can lead to a range of disorders, including cancer and arthritis. Overeating is linked with an increase in free radicals, and researchers recently found that calorie restriction—a diet restricted in calories but adequate in proteins, vitamins, and minerals—reduces the oxidative damage created by free radicals. , a healthy body weight was linked to reduced oxidative stress In addition to looking at diet, researchers also are exploring the role that exercise might play in reducing oxidative damage in cells

some proposals that certain vitamin supplements—mainly a group called "antioxidants," which includes vitamin C, vitamin E, and beta-carotene—might help to slow the aging process and improve the health of older adults

The theory is that antioxidants counteract the cell damage caused by free radicals, which are produced both by the body's own metabolism and by environmental factors such as smoking, pollution, and harmful chemicals in the diet (Jabeen & others, 2018; Jeremic & others, 2018; Tonnies & Trushina, 2017). When free radicals cause damage (oxidation) in one cell, a chain reaction of damage follows. Antioxidants are theorized to act much like a fre extinguisher, helping to neutralize free-radical activity and reduce oxidative stress

Because of the inadequate quality of many nursing homes and the escalating costs for nursing home care, many specialists in the health problems of the aged stress that home health care, elder-care centers, and preventive medicine clinics are good alternatives

They are potentially less expensive than hospitals and nursing homes (Rotenberg & others, 2018). They also are less likely to engender the feelings of depersonalization and dependency that occur so often in residents of institutions. Currently, there is an increased demand for, but shortage of, home-care workers because of the increase in the population of older adults and their preference to stay out of nursing homes (Barooah & others, 2019).

late adulthood, which begins in the sixties and extends to approximately 120 to 125 years of age.

This is the longest span of any period of human development—50 to 60 years. Increasingly, a distinction is being made between the young-old (65 to 84 years of age) and oldest-old (85 years and older). An increased interest in successful aging is producing a portrayal of the oldest-old that is more optimistic than past stereotypes. Interventions such as cataract surgery and a variety of rehabilitation strategies are improving the functioning of the oldest-old. Many experts on aging prefer to talk about the categories of young-old and oldest-old in terms of function rather than age. Recall that we have described age not only in terms of chronological age but also in terms of biological age, psychological age, and social age. Thus, in terms of functional age—the person's actual ability to function—an 85-year-old might well be more biologically and psychologically ft than a 65-year-old.

more about visual, color and depth perception decline the aging

This visual decline often can be traced to a reduction in the quality or intensity of light reaching the retina (Nag & Wadhwa, 2012). At 60 years of age, the retina receives only about one-third as much light as it did at 20 years of age (Scialfa & Kline, 2007). In extreme old age, these changes might be accompanied by degenerative changes in the retina, causing severe diffculty in seeing. sensory decline in older adults is linked to a decline in cognitive functioning (Ji, Peng, & Mao, 2019). In a recent study, declines in visual acuity, contrast sensitivity, and depth perception were associated with cognitive decline in older adults Color vision also may decline with age in older adults as a result of the yellowing of the lens of the eye (Scialfa & Kline, 2007). This decline is most likely to occur in the green-blue-violet part of the color spectrum. As a result, older adults may have trouble accurately distinguishing between objects of closely related colors, such as navy blue socks and black socks. As with many types of perception, depth perception changes little after infancy until adults become older. Depth perception typically declines in late adulthood, which can make it diffcult for an older adult to determine how close or far away or how high or low something is (Bian & Anderson, 2008). A decline in depth perception can make steps or street curbs diffcult to manage.

The New England Centenarian Study (NECS) began in 1994 under the direction of

Thomas Perls

What chance do you have of living to be 100? Genes play an important role

additional factors at work, such as family history, health (weight, diet, smoking, and exercise), education, personality, stress, and lifestyle (Belenguer-Varea & others, 2020; Diekmann & Bauer, 2019). Recall that in the epigenetic approach, there is an increased focus on identifying gene × environment (G × E) interactions that infuence development (Lindahl-Jacobsen & Christensen, 2019). For example, a Chinese study found that a combination of particular FOXO genotypes and drinking tea was associated with the prevention of cognitive decline in the oldest-old, aged 92+

Cellular clock, free-radical, mitochondrial, sirtuin, and mTOR pathway theories attempt to explain aging at genetic and cellular levels. In contrast, hormonal stress theory argues that ...

aging in the body's hormonal system can lower resistance to stress and increase the likelihood of disease. When faced with external challenges such as stressful situations, the human body adapts by altering internal physiological processes (van Deurzen & Vanhoutte, 2019). This process of adaptation and adjustment is referred to as allostasis. Allostasis is adaptive in the short term; however, continuous accommodation of physiological systems in response to stressors may result in allostatic load, a wearing down of body systems due to constant activity. Normally, when people experience stressors, the body responds by releasing certain hormones. As people age, the hormones stimulated by stress remain at elevated levels longer than they did when people were younger. These prolonged, elevated levels of stress-related hormones are associated with increased risks for many diseases, including cardiovascular disease, cancer, diabetes, and hypertension. Recently, a variation of hormonal stress theory has emphasized the role of declining immune system functioning in aging. In a recent study, the percentage of T cells (a type of white blood cell essential for immunity) decreased in older adults in their seventies, eighties, and nineties. . Aging contributes to immune system defcits that give rise to infectious diseases in older adults

mitochondria—tiny bodies within cells that supply essential energy for function, growth, and repair —might play in aging (Ahmadi, Golalipour, & Samaei, 2019) (see Figure 4). Mitochondrial theory states that ...

aging is due to the decay of mitochondria. Mitochondrial theory emphasizes that this decay is primarily caused by oxidative damage and loss of critical micronutrients supplied by the cell. Defects in mitochondria are linked with cardiovascular disease (Roushandeh, Kuwahara, & Roudkenar, 2019); neurodegenerative diseases such as Alzheimer disease (X. Li & others, 2020b) and Parkinson disease (Zhi & others, 2019); diabetic kidney disease (Forbes & Thorburn, 2018); and impaired liver functioning (Stevanovic & others, 2020). Mitochondria also likely play important roles in neuronal plasticity (Lees, Johnson, & Ashby, 2020). However, it is not known whether the defects in mitochondria cause aging or are merely accompaniments of the aging process

The most frequent pain complaints of older adults are ...

back pain (40 percent), peripheral neuropathic pain (35 percent), and chronic joint pain (15 to 25 percent) (Denard & others, 2010). The presence of pain increases with age in older adults, and women are more likely to report having pain than are men (Tsang & others, 2008). In a recent research review, it was concluded that older adults have lower pain sensitivity but only for lower pain intensities.

A national survey found that 42.8 percent of U.S. adults 60 years of age and older were obese in 2017-2018 (Centers for Disease Control and Prevention, 2020). This fgure is lower than the 44.8 percent of individuals 40 to 59 years of age who were obese. A large-scale study found a substantial link between being overweight/obese and having a higher mortality risk (Masters & others, 2013). However, some studies have reported that overweight adults live longer than normal-weight adults or that being overweight is not a risk factor for earlier death, especially in older adults

being overweight was associated with lower all-cause mortality but being obese was associated with higher all-cause mortality It's not clear why a few extra pounds that place someone in the overweight category might be linked to longevity. Possibly for some older adults, such as those recovering from surgery or those who develop pneumonia, the extra pounds may be protective. Some researchers argue that research evidence revealing a link between being overweight and living longer is likely due to inclusion of participants who have preexisting diseases (sometimes labeled "reverse causality") or sarcopenia (loss of lean body mass

An extensive research review evaluated the effectiveness of two types of interventions in improving older adults' driving:

cognitive training and education (Ross, Schmidt, & Ball, 2013): Cognitive training. Cognitive training programs have shown some success in older adults, including improving their driving safety and making driving less diffcult. In one study conducted by Karlene Ball and her colleagues (2010), training designed to enhance speed of processing produced more than a 40 percent reduction in at-fault crashes over a six-year period. Education. Results are mixed regarding the effectiveness of educational interventions that seek to improve older adults' driving ability and to reduce their involvement in traffc accidents

Georgia Centenarian Study conducted by Leonard Poon and his colleagues ...

concluded that social dynamics involving life events (experiencing a higher number of negative life events is linked to lower self-rated health), personality (conscientiousness is positively associated with higher levels of physical and mental health), cognition (cognitive measures are better predictors of mental health than physical health), and socioeconomic resources and support systems (social, economic, and personal resources are related to mental and physical health) contribute to the health and quality of life of older adults, including centenarians. And in a recent study of U.S. and Japanese centenarians, in both countries, health resources (better cognitive function, fewer hearing problems, and positive activities in daily living) were linked to a higher level of well-being

In a classic study, Judith Rodin and Ellen Langer (1977) found that an important factor related to health, and even survival, in a nursing home is the patient's feelings of ...

control and self determination. A group of elderly nursing home residents were encouraged to make more day-today choices and thus feel they had more responsibility for control over their lives. They began to decide such matters as what they ate, when their visitors could come, what movies they saw, and who could come to their rooms. the residents who had been given responsibility and control were more alert and active, and said they were happier, than the residents who were only encouraged to feel that the staff would try to satisfy their needs. And the "responsible" or "self-control" group had signifcantly better improvement in their health than did the "dependent" group. Even more important was the fnding that after 18 months only half as many nursing home residents in the "responsibility" group had died as in the "dependent" group (see Figure 17). Perceived control over one's environment, then, can literally be a matter of life or death.

Intriguing explanations of why we age are provided by three categories of biological theories:

evolutionary theory, genetic/cellular process theories, and hormonal stress theory.

Hearing impairment usually does not become much of an impediment until late adulthood (Moore, Mariathasan, & Sek, 2020). Only 19 percent of individuals from 45 to 54 years of age experience some type of hearing problem

hearing loss defned as an inability to hear sounds at frequencies higher than 25 dB with their better ear. Older adults often don't recognize that they have a hearing problem, deny that they have one, or accept it as a part of growing old. Also, a study that spanned 10 years found that poor nutrition and a lifetime of smoking were linked to more rapid onset of hearing diffculties in older adults. Hearing loss in older adults is linked to declining performance in activities of daily living, cognitive functioning, and language ess time spent out of home and in leisure activities (Mikkola & others, 2016), increased falls (Jindal & others, 2019), reduced cognitive functioning (Bowl & Dawson, 2019), and loneliness. initiation of hearing aid use in older adults was linked to either stable or improved executive function 18 months later (Sarant & others, 2020). And in another study, older adults' hearing aid use was associated with less loneliness

Life expectancy in the United States is predicted to increase to 83.3 years for women and 79.5 years for men by 2030. However, the United States, although expected to increase in life expectancy, has one of the ...

lowest growth rates in life expectancy among all the countries in the study. South Korea is projected to have the highest life expectancy in 2030, with South Korean women predicted to have an average life expectancy of 90.8, the first nation to break the 90-year life expectancy barrier.

How do centenarians view their lives? What are their opinions about why they have been able to live so long?

made up his mind to do so, focused on what is good now and not give in to negative thoughts. Ruth also believes that staying busy and always moving forward are keys to longevity, being active, sense of humor, living moderately, and sleeping well,

benefts conferred by evolutionary selection decrease with age (Baltes, 2003). In the evolutionary theory of aging ...

natural selection has not eliminated many harmful conditions and nonadaptive characteristics in older adults (Laisk & others, 2019). Why? Because natural selection is linked to reproductive ftness, which is present only in the earlier part of adulthood. . For example if Alzheimer disease occurred earlier in development, it might have been eliminated many centuries ago. Evolutionary theory, however, has its critics. One criticism is that the "big picture" idea of natural selection leading to the development of human traits and behaviors is diffcult to refute or test because evolution occurs on a time scale that does not lend itself to empirical study. Another criticism is the failure of evolutionary theory to account for cultural infuences

the role of antioxidants in health?

no link was found between antioxidant vitamin intake and mortality (Henriquez-Sanchez & others, 2016; Stepaniak & others, 2016). Additionally, research reviews have not supported the belief that antioxidant vitamin supplements can reduce the incidence of cancer and cardiovascular disease (Khodaeian & others, 2015; Paganini-Hill, Kawas, & Corrada, 2015). And in a recent analysis, it was concluded that antioxidant supplements do not increase the life span and even can increase the incidence of diseases (Milisav, Ribaric, & Poljsak, 2018). However, a meta-analysis of seven studies concluded that dietary intakes (not vitamin supplements) of vitamins E, C, and betacarotene were linked to a reduced risk of Alzheimer disease

we know about older adults suggests that the more active they are, the healthier and happier they are likely to be (Strandberg, 2019). For example, a recent study confrmed that older adults who engage in regular exercise have a higher level of life satisfaction

one study revealed that 60-year-old and older adults who were in the lowest ffth in terms of physical ftness as determined by a treadmill test were four times more likely to die over a 12-year period than their counterparts who were in the top ffth of physical ftness (Sui & others, 2007). A longitudinal study found that men who exercised regularly at 72 years of age had a 30 percent higher probability of still being alive at 90 years of age than their sedentary counterparts (Yates & others, 2008). And a study of more than 11,000 women found that low cardiorespiratory ftness was a signifcant predictor of death

How do vision, hearing, taste, smell, touch, and sensitivity to pain change in late adulthood?

researchers have found that visual decline in late adulthood is linked to (a) cognitive decline (Monge & Madden, 2016), and (b) having fewer social contacts and engaging in less challenging social/leisure activities (Cimarolli & others, 2017). For example, in a longitudinal study of individuals 60 years and older, visual and hearing diffculties predicted cognitive diffculties in verbal fuency, processing speed, and memory 8 years later (de la Fuente & others, 2019). In this study, cognitive decline was steepest in individuals with both visual and hearing problems.

life expectancy is

the number of years that the average person born in a particular year will probably live

important to remember that health and well being of adults are not the only things that have contributed to increased longevity but also ...

the substantial reduction in infant deaths in recent decades.