Week 2 nutrition

A hundred years ago, however, it was a novel idea that most medical experts dismissed because they thought only

"germs" caused disease.

analytic study design

*first three on triangle -provide more evidence -allow for testing of epidemiological hypotheses -use explicit comparison group -best results

placebo fake treatment

,such as a sham pill, injection, or medical procedure

analytic study design split into two groups -interventional experimental -observational studies

-interventional experimental (top one) -observational studies (bottom 2)

hierarchy of studies (triangle)

-randomized controlled trails/intervention studies -cohort studies -case-control studies -cross sectional studies -ecological studies -case series -case reports

peer review

Before articles are accepted for publication, they undergo peer review, a critical analysis conducted by a group of "peers." Peers are investigators who were not part of the study but are experts involved in re-lated research.

Limitations of Epidemiological Studies

By studying differences in dietary practices and disease occurrences among populations, epidemiologists may establish nutritional hypotheses for the prevalence of certain diseas- es. If one group of people is more likely to develop a certain health disorder than another group, and the two populations consume very different diets, scientists can speculate about the role diet plays in this difference. When two different natural events occur simultaneously within a population, it does not necessarily mean they are correlated

Scientific studies have their own limitations.

Companies can influence study outcomes and since it's hard to get funding for nutrition research, industry funds a large portion of nutrition research. Industry certainly has a stake in the outcome of nutrition research and even peer-reviewed journals (this will be defined in the reading) occasionally let poorly conducted research in. Studies have been done about studies and found that research results are likely to favor funder interests

pseudoscience

Consumers also need to be alert for promoters' use of pseudoscience, the presentation of information masquerading as factual and obtained by scientific methods presentation of information masquerading as factual and obtained by scientic methods

spreading on the media

If the information is simplistic and sensational, such as a finding that drinking green tea can result in permanent weight loss, it is more likely to be reported in the popular press.

analyzing data from study

Nutrition researchers use a variety of statistical methods to analyze data collected from observations and experiments. These methods may enable the researchers to find rela- tionships between the variables and health outcomes that were studied. As a result, sci- entists can determine whether their hypotheses are supported by the data.

skeptical consumer of nutrition information, you need to be aware of "red flags,"

Promises of quick and easy remedies for health-related problems Claims that sound too good to be true, Scare tactics that include frightening, false, or misleading statements about a food, dietary practice, or nutrition-related health condition Attacks on conventional scientists and health care practitioners,

diff between quackery and malpractice

Quackery entails the use of methods that are not scientifically accepted, but malpractice, on the other hand, occurs when a licensed health professional fails to meet diagnosis and treatment standards established by their profession.

research biases

Research Bias Scientists expect other researchers to avoid relying on their personal attitudes and biases when collecting and analyzing data, and to evaluate and report their results objec- tively and honestly. This process is important because much of the scientific research that is conducted in the United States is supported financially Peer-reviewed journals usually require authors of articles to disclose their affiliations and sources of financial support. Such disclosers may appear on the first page or at the end of the article

Dietary supplement manufacturers, promoters, and sales outlets make considerable money as a result of consumer ex- pectations in the health-promoting powers of their products.

Sales of dietary supplements totaled nearly $19 billion in 2002.10 In a recent survey, 52% of adult Americans reported taking a dietary supplement during the past month.11

Why do scientists often use placebos? placebo effect

Some people report positive or negative reactions to a treatment even though they received the placebo. If a patient believes a medical treatment will improve his or her health, the patient is more likely to report positive results for the therapy. Such wishful thinking is called the placebo effect.

following up with more research

The results of one study are rarely enough to gain widespread acceptance for new or un- usual findings or to provide a basis for nutritional recommendations. Thus, the findings obtained by one research team must be supported by those generated in other studies. If the results of several scientific investigations conducted under similar conditions confirm the original researcher's conclusions, then these findings are more likely to be accepted by other nutrition scientists.

problems facing scientist and their studies

Unfortunately, many scientists are faced with perceived and real sources of conflicts of interest, which may either negatively influence science or serve as fodder for critics to wantonly dismiss well-conducted science. Financial conflicts are the most discussed, with financial ties to industries serving as the source of many expressions of concern regarding potential distortions of research reporting.

How can you become a more careful, critical consumer of nutrition-related information?

What motivates the authors, promoters, or sponsors to provide the information? Do you think they are more interested in your health and well-being or selling their products? (salesperson/clerk health food store) Does the promoter or advertisement rely on anecdotes or testimonials? As mentioned earlier, these sources of information are unreliable. Reliable nutrition information is research- or evidence-based.

registered dietitian

When you need food and nutrition information based on fact or need to know how a healthy diet improves health and fights disease—rely on qualified professionals in the field.

using the internet wisely

Who or what organization sponsors the site? Is the information intended to promote sales? Be wary if the site discusses benefits of dietary supplements and enables you to purchase these products online. Furthermore, a site is likely to be unreliable if it includes comprehensive disclaimers such as, "The manufacturer is not responsible or obligated to verify statements," or "The FDA has not evaluated this website. This product is not intended to diagnose, cure, or prevent any disease." Also avoid sites that publish disclaimers Be wary of websites that are authored or sponsored by one person, or sites that promote or sell products for profit

What is the benefit of using a large sample size in an experiment? a. Chance variation can be ruled out. b. There will be no placebo effect. c. The experiment will be double-blind. d. The control group will be similar to the experimental group.

a Large sample sizes are needed in order to achieve "statistical significance" when the results are analyzed. Generally, a sample size larger than 30-50 subjects will give the researchers statistically significant results. Double-blind, placebo, and control groups are all research techniques that are independent of sample size. A study can have a large sample size, but be poorly designed and/or not use control groups, placebos, and/or double-blinded treatments.

testimonial,

a personal endorsement of a product. People are usually paid to provide their testimonials for advertisements, therefore their remarks may be biased (slanted) in favor of the product.

Understanding the nature of science involves: [mark all correct answers] a. The design of meaningful studies b. The testing of hypotheses c. The establishment of theories d. The feeling that something is right or true.

abc Understanding the nature of science involves weighing the criteria of evidence, design of meaningful studies, weighing of possibilities, testing of hypotheses, and the establishment of theories. These are all critical parts of the scientific method that makes it possible to draw reliable conclusions about the physical universe. Science should upon self-questioning, testing, & analytical thinking that should make it hard to fool yourself or avoid facing the facts. A belief, on the other hand is just a feeling that something is right or true (

Giorgio A. Tsoukalos from the History Channel's Ancient Aliens series argues that aliens must exist because no one is able to prove that they do not. This is an example of: a. logical contradiction. b. an elementary fallacy. c. appealing to a false authority. d. a conclusion based on arbitrary conventions of human culture.

b . "Many pseudoscientists base their claims on incompleteness of information about nature, rather than on what is known at present. But no claim can possibly be supported by lack of information. The fact that people don't recognize what they see in the sky means only that they don't recognize what they saw. This fact is not evidence that flying saucers are from outer space. The statement "Science cannot explain" is common in pseudoscience literature. In many cases, science has no interest in the supposed phenomena because there is no evidence it exists; in other cases, the scientific explanation is well known and well established, but the pseudoscientist doesn't know this or deliberately ignores it to create mystery"

Among the following, which is the major weakness of a laboratory-based study? a. The costs are usually high. b. It is difficult to replicate the findings. c. The results cannot necessarily be applied to human beings. d. Experimental variables cannot be easily controlled.

c correct Right! Good job! Animals used in experiments are not humans, so results from studies involving animals don't necessarily apply to humans. This is also true for in vitro studies. The results from an experiment on single cells or tissue may not be replicated when the tissue or cells are in their "natural environment"--the human body.

What is biochemical individuality? a. The study of the chemical processes within living organisms. b. The correct notion that that everyone's health needs are so unique that federal/scientific guidelines for health do not apply. c. The false notion that everyone's health needs are so unique that federal/scientific guidelines for health do not apply. d. The labeling of normal symptoms of aging as a disease that can be cured through "alternative" treatments.

c "Supplementation is encouraged by a distorted concept of biochemical individuality—that everyone is unique enough to disregard the Recommended Dietary Allowances (RDAs). Quacks won't tell you that scientists deliberately set the RDAs high enough to allow for individual differences. A more dangerous appeal of this type is the suggestion that although a remedy for a serious disease has not been shown to work for other people, it still might work for you. (You are extraordinary!)

registered dietitians are

college-trained professionals who have extensive knowledge of foods, nutrition, and dietetics, the applica- tion of nutrition and food information to treat many health-related conditions.

Which of the following would be an example of a peer reviewed journal? You can copy and paste the links into your browser to check out the specific examples. a. Scientific American (http://www.scientificamerican.com/) b. National Geographic Magazine (http://www.nationalgeographic.com/magazine/) c. Men's Health (http://www.menshealth.com/) d. Nutrition in Clinical Practice (http://ncp.sagepub.com/)

d For more information on how to assess for a peer reviewed journal, check out these websites (you'll need to copy & paste the links into your browser): What Is A Peer-Reviewed Article? from http://guides.lib.jjay.cuny.edu/c.php?g=288333&p=1922599 and How to recognize peer-reviewed (refereed) journals from http://www.angelo.edu/services/library/handouts/peerrev.php.

peer review

expertcriticalanalysisofaresearch article prior to its publication Before articles are accepted for publication, they undergo peer review, a critical analysis conducted by a group of "peers." Peers are investigators who were not part of the study but are experts involved in re- lated research. If peers agree that a study was well conducted, its results are fairly represented, and the research is of interest to the journal's read-ers, these scientists are likely to recommend that the journal's editors publish the article.

It is possible for research or a researcher to be completly free of bias. True False

false Any research endeavor needs to acknowledge that "there are few if any perfect research studies and the limitations need to be carefully identified, discussed, and implications of limitations incorporated into the interpretation of the findings"

control group

group being studied that receives a placebo

Quackery

involves promoting useless medical treatments.

correlation

relationship between variables A correlation is a relationship between variables. A correlation occurs when two variables change over the same period, such as when a country's percentage of overweight people increases as its population's intake of sugar-sweetened soft drinks also increases.

placebo effect

response to a placebo

self-treatment and/or family in-home treatment; folk healer and quackery differences

self-treatment and/or family in-home treatment; give advice to your neighbors; or utilize a "folk healer" consistent with your cultural and ethnic traditions (for example, a Navajo person diagnosed with an illness attending a 'hand trembling' ceremony). However, folk medicine and quackery are closely connected because folk medicine often provides a basis for commercial exploitation and can form the basis for a claim that the supplement/herb/practice/remedy is "time tested"

correlations

since can't prove cause and effect in observational studies. can only come up with correlations which only prove the correlations involving relationship between variables.

When an experiment or study is completed and the results analyzed, researchers

summarize the findings and seek to pub- lish articles with information about their investigation in sci- entific journals.

when a study has validity

the conclusions support the findings

retrospective study

type of study that determines factors that may have contributed to the development of disease researchers identify a group of people who al- ready suffer from a disease and compare them, particularly their past lifestyle practices, to a group of people with similar characteristics who do not have the disease. The results may identify long-term factors that may have been responsible for the illness

prospective study

type of study that follows a group of healthy people over time to determine characteristics associated with the development of diseases follows a large group of healthy people over time to deter- mine whether those with a certain characteristic develop a disease and those with- out that characteristic remain disease-free

junk science

untested and unproven science that is presented as facts

Consumers need to recognize that conflicting findings often result from dif- ferences in the ways (when studies are done and one proves and the other disproves)

various studies are designed. Even when investigating the same question, different groups of scientists often conduct their studies and analyze the re- sults differently. For example, the numbers, ages, and physical conditions of subjects; the type and length of the study; the amount of the treatment provided; and the sta- tistical tests used to analyze results typically vary among studies.

how to identify junk science

-some studies use animals results and apply to humans (animals have limited relevance to human health) -statistical science is different than biological science in scientific study (ex one group who ate a banana ran faster than group didn't-- doesn't mean the group that ate the banana can outrun a tiger) -how many people did they test it on? what else where those people doing in addition to lose weight -if study is confirmed by additional studies the study might be an outlier

the peer review of research results

-vital part of the scientific method -research should try to get published in preview journals in order to share results of their studies this is a research publication in which fellow scientist review publication to asses whether they are scientific accurate

positive correlation negative correlation no correlation

1 thing increases the other increases. ex: smoking increase= increase cancer 1 thing increases, other decreases ex: increase fruit/vegs= decrease cancer no conclusions to be made. most conclusions lead to more questions

Some examples of white-hat bias include the following:

1) selectively citing only the portion of results that favor a particular viewpoint (also called "unbalanced citation"); 2) inappropriate inclusion or exclusion of data in reviews; 3) is communication within research conclusions, press releases, or media about research results; 4) publication bias (in this case, only publishing results that are perceived to match a preconceived beneficial effect); and 5) only making conclusions about results consistent with the hypothesis (3). Each of these distortions was described in other ways, but white-hat bias seems predicated on researchers' beliefs that such distortions will improve human health"

more detailed final steps nutrition research

1. Hypothesis supported (or not) in research 2. submit findings publications 3. articles/findings (undergo the perreview proces) 4. findings are replicated by other research 5. develop scientific theory (if others replicate it) 6. establish conclusions

scientific method

1. Make observations that generate questions 2. Formulate hypotheses to explain events 3. Design studies, perform tests, and collect data 4. Analyze data and draw conclusions based on the results 5. Share results with peers (report findings) 6. Conduct more research, the results of which may confirm or refute previous findings

final steps in nutrition research

1. publish in peer review journal 2. effects are repeated by other researches 3. consensus is established by scientific study

set of 6 steps of scientific method

1. question (pose problem want to solve) 2. hypothesis (predict the outcome) 3. experiment (order, investigate or dispose hypothesis) 4. observation (statement or knowledge gained through sense or the use of scientific equipment

If a hypothesis is not supported by the resulting research, that means the scientists didn't learn anything. True False

F correct Right! Good job! Having your hypothesis disproven is disappointing, but not the end of the world, in fact it should just raise more questions to study!

dietary supplements have been thoroughly evaluated?

Few dietary supplements have been thoroughly evaluated by reputable scientists. In some instances, these products have been scientifically tested, but the bulk of the research has shown that most dietary

What is nutrition quackery?

Nutrition quackery is the selling of products or services of questionable scientific validity. Nutrition quackery is the promotion & selling of health products & services of questionable validity. A quack is a person who promotes these products and services in order to make money

case-control study

type of study in which individuals who have a health condition are compared with individuals who have similar characteristics but do not have the condition Epidemiologistsanddietitiansoften rely on physical examinations of people to obtain health data.

However, people who tell you that the "medi- cal/scientific establishment and drug companies are hiding information

about natural cures from you just to make money from your misery..." are using scare tactics to build mistrust in the medical establishment. People's lives have been improved by contributions of medical researchers, such as physicians

Quackery can be defined as: a. Failure by a health professional to meet accepted standards of diagnosis and treatment. b. The promotion & selling of health products & services of questionable validity. c. Unproven methods of treatment currently under scientific study. d. Folk remedies given by family members to each other.

b

Which of the following would be a poor source of nutrition information? a. A peer-reviewed nutrition journal you found in PubMed. b. A men's health & nutrition magazine you bought at GNC. c. The USDA's MyPlate website. d. The website of the American Heart Association.

b Before making dietary and lifestyle changes based on media reports, read with a critical eye and ask: Was the research finding published in a peer-reviewed journal? Was the study done using animals or humans? Do the study participants resemble me? Is this the first time I've heard about this? Wait until research findings are confirmed and consensus reached by reputable health organizations before making changes . "The increased use of research summaries on websites makes it even more challenging for consumers to ascertain whether a research report has been peer reviewed and who funded the research and/or website. In general, the research literacy of consumers and the media would need significant enhancement if this were to be the desired end state"

What is the benefit of using placebos in an experiment? a. All subjects are similar. b. All subjects receive a pill, shot, or technique. c. Neither subjects nor researchers know who is receiving treatment. d. One group of subjects receives a treatment and the other group receives nothing.

b correct Right! Good job! Our attitudes are a pretty powerful influence on our health. If we take something that we think we'll help us, we'll feel better. Placebos are given during research studies to mitigate this effect. Making sure that all subjects are similar depends on what a researcher is studying. It would be important for subjects in a control group (the one receiving standard treatment and/or the placebo) and subjects in the experimental group to be similar, but just the fact that researchers gave a placebo to one group does not guarantee that the subjects in that group are different from the experimental group—that relates to the study design, not the use of a placebo. When neither the subjects nor the researchers know who is getting the placebo vs the treatment, that is called a double-blind study, but placebos can still be given when researchers know who is receiving what. Again, this relates more to study design and researcher bias than the effect of the placebo on the subjects themselves. If one group received a treatment and the other group received nothing, that is when the placebo effect can be seen: the group receiving the treatment may just feel better because they're receiving a treatment, whether or not the treatment actually is working.

Which of the following must a person aspiring to be a registered dietitian complete? [mark all correct answers] a. They must obtain a PhD in Nutritional Science. b. They must graduate from an accredited undergraduate dietetics program. c. They must pass a national certifying examination. d. They must complete an accredited dietetic internship program.

bcd Registered dietitians have completed accredited undergraduate programs and real-world graduate internships. They have also passed a board certified national exam and must keep up their registration with continuing education. A PhD program on the other meets only the specifications of the university offering the program—not the national, certifying body for registered dietitians (Commission on Dietetic Registration [CDR]). Undergraduate dietetics programs and dietetic internships must meet the requirements laid out by CDR. A student who graduates with a nutrition degree from an UNcredited program is not eligible to apply for a dietetic internship or to sit for the national exam. This process is similar to what nurses, doctors, and lawyers all go through.

direct or positive correlation An inverse or negative correlation

because the two variables—body weight and regular soft drink consumption—are changing in the same direction; they are both increasing. occurs when one variable increases and the other one decreases.

descriptive studies

bottom 4 -dont asses disease etiology (casualty) -use generate hypothesis -described the relationship between the exposure and disease (try to explain, but can't confirm) -do these experiment to generate hypothesis -used to allocate responses and plan programs

"Natural remedies" that promotors believe are effective a. are always safe to use if they are all natural. b. are effective if used and dosed properly. c. are organically produced and grown. d. are not proven to be safe or effective.

d Just because something is "natural" doesn't mean its ineffective, but its true that the majority of "alternative" therapies have not been shown to be effective. Moreover, a supplement manufacturer does not have to demonstrate that their product is safe or effective prior to it going to market!

media problems

they often post when research is conducted well before established conclusions which take time

In the same series, Mr. Tsoukalos argues that aliens must exist because if you ask a person what an alien looks like, they'll describe a "Grey" (little body, huge eyes, bald head, slits for nose, etc). Since everyone describes largely the same thing, this must mean that everyone has really seen an alien. This is an example of: a. logical contradiction. b. an elementary fallacy. c. appealing to a false authority. d. arbitrary conventions of human culture.

d correct Right! Good job! If we were to base scientific conclusions on arbitrary conventions of human nature, then we must also admit that Santa Claus exists. You can ask any American what Santa Claus looks like, they'd all give you similar descriptions of an old European man with white beard, red fur outfit, reindeer and so forth. So then we must conclude that Santa Claus exists!?

What is the benefit of using controls in an experiment? a. The size of the groups can be very large. b. The subjects do not know anything about the experiment. c. The subjects who are treated are balanced against the placebos. d. The subjects are similar in all respects except for the treatment being tested.

d correct Right! Good job! In order to be able to tell if a treatment was the actual cause of the outcome, researchers need a "control" group. Review the required reading for more information.

double blinded studies

experimental design in which neither the participants nor the researchers are aware of each participant's assignment Randomized human studies are usually double-blind—that is, both the investigators and subjects are not aware of the subjects' group assignments. Codes are used to identify a subject's group membership, and this information is not revealed until the end of the study. Maintaining such secrecy is important during the course of a human study involving placebos, because researchers and subjects may try to predict group assignments based on their expectations.

peer review

expert critical analysis of a research article prior to its publication Randomized human studies are usually double-blind—that is, both the investigators and subjects are not aware of the subjects' group assignments. Codes are used to identify a subject's group membership Maintaining such secrecy is important during the course of a human study involving placebos, because researchers and subjects may try to predict group assignments based on their expectations.

treatment or experimental group

group being studied that receives a treatment In some prospective studies, researchers perform an intervention, such as a spe- cific dietary or behavioral change, on a group of people (the treatment or experimental group), and the results of the intervention are monitored over a long period. Data collect- ed from the treatment group are compared to a population with similar characteristics who has not made the specific change during the same period (the control group) If the data indicate that the health of the treatment group differs from the health of the con- trol group, the researchers may associate the difference with the intervention

real world" we use the term theory differently than in science.

in life, we use the word "theory" to indicate a speculation. However, in the natural and biological sciences, theory is used to indicate the scientific consensus indicator around a set of facts, principles, and/or phenomena

White-hat bias"

is a form of nonfinancial bias, defined as bias leading to distortion of research-based information in the service of what may be perceived as righteous ends.

A hypothesis

is a possible explanation for an observation

scientific method

is how we understand the nature of science. It involves criteria of evidence; design of meaningful studies; weighing of possibilities; testing of hypotheses; and establishment of theories.

Epidemiology

is the study of disease rates among differ- ent population groups, factors associated with the occurrence of diseases, and how diseases spread in a population.

be skeptical about claims

it is prudent to be skeptical and not believe what you read or hear about nutrition-related topics without investigating the credibility of their sources. To be a careful consumer, do not assume that all nutrition information presented in the popular media is reliable.

Nutrition researchers can perform controlled laboratory experiments on components derived from

living organisms (in vitro or "test tube" experiments) or on whole living organisms (in vivo experiments). Nutrition scientists often conduct in vivo experiments on small mammals, particularly mice or rats that are raised for experimentation pur- poses. These rodents are inexpensive to house in laboratories, and their food and other living conditions can be carefully controlled

Americans each year spend billions of dollars on supplements most

of which do not work and some which are harmful

scientific method

set of procedures that scientist use to gain knowledge about the world

The Dietary Supplement Health and Education Act of 1994 (DSHEA)

severely weakened the government's ability to regulate the dietary supplement industry. DHSEA "does not require that dietary supplements (defined broadly to include many substances, such as herbs and amino acids, that have no nutritive value) be shown to be safe or effective before they are marketed. The FDA does not scrutinize a dietary supplement before it enters the marketplace. Supplement manufactures do not have to submit safety testing information to the Food & Drug Administration (FDA) prior to selling their product on the market, nor do they have to prove it actually works (unlike with medications

An alternative practitioner is being sued by the family of a cancer victim. The family is arguing that the practitioner charged the family member a lot of money for something that not only didn't work, but dissuaded the victim from continuing conventional medical treatment (e.g. chemo and/or radiation). In court the practitioner argues that the reason their supplements didn't work to cure the cancer is because the conventional methods "knocked out" the individual's immune system so it couldn't then respond to the alternative therapies. This is an example of a common technique quack's use to justify their

shifting blame Right! Good job! "Quacks also capitalize on the natural healing powers of the body by taking credit whenever possible for improvement in a patient's condition. One multilevel company—anxious to avoid legal difficulty in marketing its herbal concoction—makes no health claims whatsoever. "You take the product," a spokesperson suggests on the company's introductory videotape, "and tell me what it does for you." An opposite tack—shifting blame -- is used by many cancer quacks. If their treatment doesn't work, it's because radiation and/or chemotherapy have "knocked out the immune system"'

Many variables may influence the outcome of an epidemiological study. Thus, scien- tists performing research to determine the effect or effects of a single variable need to control

the influence of other variables.