chapter 9

Diet and cancer

Foods that can lower risk Plant-based foods Nonstarchy vegetable and fruit intake Lower risk of esophageal, stomach, and colon cancer Cauliflower, broccoli, brussels sprouts Reduced bladder cancer in men Tomatoes Reduced prostate cancer in men Nutrients associated with lower risk Vitamins A, D, C, and E, folate, selenium Fiber Omega-3 fatty acids Foods that can increase cancer risk Red meat, especially when grilled Nitrates and nitrites in processed meats Bacon, ham, sandwich meats Ways to protect against cancer Maintain a healthy weight Participate in regular physical activity Avoid overconsumption of energy-dense foods Consume a varied, healthy, plant-based diet Avoid tobacco Limit alcohol intake

Parathyroid hormone

Parathyroid hormone, also called parathormone or parathyrin, is a hormone secreted by the parathyroid glands that is important in bone remodeling, which is an ongoing process in which bone tissue is alternately resorbed and rebuilt over time. Wikipedia

Provitamins

Provitamins Substances found in foods that are not directly usable by the body Converted to an active form once absorbed Example: beta-carotene--> vitamin A

What are vitamins?

Tasteless, organic compounds Required in small amounts Functions: Regulate metabolism Help convert energy in fat, carbohydrate, and protein into ATP Promote growth and reproduction Deficiencies can result in potentially serious symptoms.

Vitamin A- food sources, deficiencies, toxicity, characteristics, functions

The liver is the main storage site for vitamin A A family of fat-soluble retinoids (retinol, retinal, retinoic acid) Preformed vitamin A is found primarily in animal foods. Some plants contain provitamin A compounds, which are converted to retinol in your body. Carotenoids, including beta-carotene, are pigments that give color to carrots, butternut squash, and cantaloupe. All forms of vitamin A are absorbed by active transport with bile salts and micelles. Beta-carotene is absorbed by passive diffusion. Reduced with high fiber intake Improved in cooked foods Most forms of vitamin A are packaged into chylomicrons enter lymph Retinoic acid is attached to albumin. Stored in the liver Participates in Vision Protein synthesis and cell differentiation Reproduction Bone health A healthy immune system May help fight cancer Carotenoids are antioxidants. Vitamin A: Adults Males: 900 micrograms (g) retinol activity equivalents (RAE) Females: 700 g RAE Upper limit: 3,000 g Beta-carotene: 3-6 milligrams daily Strict vegans need to meet vitamin A intake through carotenoids and beta-carotene-rich foods. Foods: pumpkin, collards, sweet potato, liver (braised), etc Too much: Excessive amounts of preformed vitamin A can accumulate to toxic levels. Toxic levels are generally a result of overconsumption of vitamin A in supplements. Hypervitaminosis A can lead to liver damage and even death. Overconsumption During pregnancy can cause birth defects in the face, skull, and CNS of the child Can potentially result in osteoporosis and bone fractures in adults. Carotenoids in foods are not toxic. Do not pose serious health problems Excess carotenoids can cause carotenodermia (yellowish of the skin) Overconsuming beta-carotene supplements May increase lung cancer risk Too little: Chronic vitamin A deficiency causes night blindness. Prolonged vitamin A deficiency leads to xerophthalmia. Leading cause of preventable blindness in children, mostly in developing countries Deficiency can lead to keratinization of epithelial tissues. Epithelial cells don't secrete mucus. Cells are unable to function properly, promoting infection.

Carotenoids

Carotenoids, including beta-carotene, are pigments that give color to carrots, butternut squash, and cantaloupe. Carotenoids are antioxidants. Strict vegans need to meet vitamin A intake through carotenoids and beta-carotene-rich foods. Carotenoids in foods are not toxic. Do not pose serious health problems Excess carotenoids can cause carotenodermia (yellowish of the skin) Overconsuming beta-carotene supplements May increase lung cancer risk Phytochemical's: -Carotenoids -Flavonoids

All Vitamins Are Organic, but Differ in Structure and Function

All vitamins contain carbon, hydrogen, and oxygen. Some vitamins contain nitrogen and sulfur. The chemical structure of each vitamin is unique. Each vitamin is a singular unit. Vitamins are absorbed intact. Vitamins perform numerous essential functions. Some vitamins have more than one role in metabolism.

Bioavailability

Bioavailability varies based on Amount in food Preparation Efficiency of digestion and absorption of food Individual nutritional status Natural or synthetic Fat-soluble vitamins are generally less bioavailable than water-soluble vitamins. Vitamins from plant foods are generally less bioavailable than those in animal foods.

Coumadin

Blood thinners It can treat and prevent blood clots.

An antioxidant works to fight free radicals by __________.

donating electrons to stabilize them

Addition of nutrients to foods to enhance quality and to prevent or correct dietary deficiencies is called __________.

fortification

A condition resulting from excess amounts of vitamins in the body is called __________.

hypervitaminosis

Carotenoids are a precursor form of __________.

vitamin A

Some research suggests that consuming too much __________ may lead to osteoporosis.

vitamin A

Anticoagulant medications such as Coumadin act by decreasing __________ activity.

vitamin K

Individuals taking anticoagulant medications need to keep a consistent intake of __________.

vitamin K

Overdosing on preformed vitamin A may lead to __________.

liver toxicity

An early sign of vitamin A deficiency is __________.

night blindness

Excessive intake of vitamin D may cause __________.

overabsorption of calcium from the intestines

The main function of vitamin K is to __________.

promote healthy blood clotting

The best dietary source of vitamin K is __________.

raw kale

The vitamin D deficiency disease in children is known as __________.

rickets

A great food source of vitamin D is __________.

salmon

Vitamin K- food sources, deficiencies, toxicity, characteristics, functions

Three forms of vitamin K Phylloquinone is found in green plants. Menaquinone is synthesized by intestinal bacteria. Menadione is the synthetic form. Most vitamin K is absorbed in the jejunum. Ten percent of vitamin K is produced by bacteria in the colon. Vitamin K is incorporated into chylomicrons and transported to the liver. When a diet is deficient in vitamin K Storage forms are transported by VLDL, LDL, and HDL. Stored mostly in the liver Promotes blood clotting Involved in synthesizing four blood-clotting factors. Thromboplastin- Is a enzyme released from damaged cells, especially platelets, that converts prothrombin to thrombin during the early stages of blood coagulation. Thrombin- Is and enzyme in blood plasma that causes the clotting of blood by converting fibrinogen to fibrin. Promotes strong bones Assists with the carboxylation of other proteins Interacts with proteins osteocalcin and matrix Gla protein (MGP), which is essential for the formation of a strong bone matrix Daily needs: Adults Men: 120 g/day Women: 90 g/day Recommendations are based on current consumption, as the amount contributed by intestinal synthesis is unknown. foods: Kale, canola oil, spinach, brussel sprouts, margarine, etc. Too much No known adverse effects Individuals taking anticoagulant medications should keep vitamin K intake consistent. Changes in intake can increase or decrease drug effectiveness. Too little Infants are born with too little vitamin K. Deficiency severe enough to affect blood clotting is extremely rare. May be a cause of hip fracture in older men and women.

Which nonprofit organization sets reliability and purity standards for dietary supplements?

U.S. Pharmacopeia

Which of the following is considered the "sunshine vitamin," due to the ability to be made by the body with sunlight exposure?

Vitamin D

Rickets

Vitamin D deficiency disease in children Bones aren't adequately mineralized with calcium and phosphorus, causing them to weaken, leading to bowed legs. On the rise in the United States due to decreased milk consumption, fear of skin cancer from sun exposure, and air pollution

Antioxidants and phytochemicals- chart

What are antioxidants? They're a group of compounds that neutralize free radicals, helping to counteract the oxidation that takes place in cells Includes Vitamin E Vitamin C Selenium Flavonoids Carotenoids Free radicals- By-products of the body's metabolic reactions Molecules with an unpaired electron, which makes them unstable Factors that increase free radical production UV light Exposure to toxins from smoking Exposure to environmental pollutants Oxidative stress is when free radicals accumulate faster than the body can metabolize them. Damages DNA and body proteins, and alters cell structure Contributes to chronic diseases Heart disease Cancer Aging Diabetes Parkinson's disease Alzheimer's disease Age-related macular degeneration (AMD) Free radical damage to the macula in the eye Most common cause of blindness in Americans over 60 AMD risk and loss of vision is reduced with supplementation. Vitamin C, vitamin E, beta-carotene Zinc and copper Cataracts Vitamins C and E and lutein and zeaxanthin may lower risk of cataracts. **Antioxidants Neutralize Free Radicals Antioxidant-rich foods also contain other protective compounds. These sources also act as antioxidants, stimulate the immune system, and interact with hormones to prevent cancers. Phytochemicals Carotenoids Flavonoids Antioxidants and phytochemicals from the diet have more health benefits than those from supplements. ** look at chart to see what phytochemicals are

A great dietary source of vitamin E would be __________.

almonds

A compound that gives foods their characteristic yellow-red pigment and is a provitamin is __________.

beta-carotene

The degree to which a nutrient is absorbed from foods and used in the body is known as __________.

bioavailability

Vitamin E- food sources, deficiencies, toxicity, characteristics, functions

Alpha-tocopherol is the most active form in the body. The synthetic form in supplements is only half as active as the natural form. Absorbed with bile salts and micelles Packaged in chylomicrons lymph circulation liver Ninety percent of vitamin E is stored in adipose tissue. Acts as a powerful antioxidant Protects cell membranes; prevents oxidation of LDL cholesterol Acts as an anticoagulant, inhibiting formation of harmful clots inside bloodstream No evidence supporting a role in prevention of cancer or other diseases has been conclusively identified. Adults need 15 mg of alpha-tocopherol equivalents. Upper limit is 1,000 mg/day Current suspicion that the upper limit may be too high foods: wheat germ, almonds, carrots, olive oil, Italian salad dressing, etc Too much No known risk of consuming too much vitamin E from natural food sources Overconsumption of synthetic form in dietary supplements and fortified foods can increase risk of a hemorrhage Too little Rare Chronic deficiency of vitamin E can cause nerve problems, muscle weakness, and free radical damage to cell membranes

Hypervitaminosis

Also known as Vitamin toxicity, Rare Results from ingesting excess vitamins, which leads to tissue saturation Can damage cells, sometimes permanently Results from supplementing with megadoses of vitamins The Dietary Reference Intakes include a Tolerable Upper Intake Level (UL) for most vitamins, to prevent excess.

Vitamin D- food sources, deficiencies, toxicity, characteristics, functions

Vitamin D is mainly stored in the fat and muscle tissue. Called the "sunshine vitamin" Derived from a reaction between ultraviolet rays and a form of cholesterol in the skin Exposure to sunlight can synthesize all of the body's vitamin D needs. Considered a conditionally essential nutrient Considered a prohormone Found in two forms Cholecalciferol (vitamin D3): Produced in the skin and found in animal foods Ergocalciferol (vitamin D2): Found in plants and dietary supplements Bone growth Calcitriol stimulates intestinal calcium and phosphorus absorption. Maintains healthy ratio of calcium and phosphorus in the blood Controls interaction between osteoblasts and osteoclasts May prevent some cancers Incidence of breast, colon, and prostate cancer is higher in individuals living in sun-poor areas of the world. May prevent diabetes Type 2 diabetes is associated with low blood vitamin D levels. Potentially helps reduce risk of some autoimmune disorders May regulate blood pressure Sun exposure cannot meet everyone's vitamin D needs. The skin pigment melanin and use of suncreens reduce vitamin D production. Sunlight intensity during winter in some locations is not sufficient to make enough vitamin D. Vitamin D needs based on dietary sources Adults 15-20 g (600-800 IU) per day, depending on age UL: 100 g Children 15 g per day UL: 50 g Foods: salmon, milk, raisin brand, tuna fish, etc Too much Vit. D: A high intake can cause loss of appetite, nausea, vomiting, and constipation. Overuse of supplements may lead to hypervitaminosis D. Hypercalcemia Can cause damaging calcium deposits in kidneys, lungs, blood vessels, and heart Can affect the nervous system and cause severe depression Too-high levels are extremely rarely caused by food intake or overexposure to the sun. Too little: Rickets: Vitamin D deficiency disease in children Bones aren't adequately mineralized with calcium and phosphorus, causing them to weaken, leading to bowed legs. On the rise in the United States due to decreased milk consumption, fear of skin cancer from sun exposure, and air pollution Other vitamin D deficiency disorders Osteomalacia: Adult equivalent of rickets Osteoporosis Muscle weakness and pain

What vitamin is made by the bacteria in the GI tract?

Vitamin K