Chapter 2: Evaluating Nutrition Information

Scientific Method: Basic Steps

1. Make observations that generate questions 2. Formulate hypotheses to explain events 3. Review current scientific literature (published studies) that relate to the questions 4. Design studies, perform tests, and collect data (facts) 5. Analyze data and draw conclusions based on the results 6. Share results with peers (report findings) 7. Conduct more research, the results of which may confirm or refute previous findings.

Direct correlation

As a population's intake of sugar-sweetened soft drinks increases, the percentage of overweight people in that population increases.

Dietary Supplements

Ask yourself if use of dietary supplements is necessary Discuss with primary care giver Watch out for possible false or exaggerated claims See reliable websites this chapter to use to learn about a supplement

Epidemiology:

Assessment of health in populations in humans and animals to decrease preventable morbidity and mortality Study of human and animal disease to estimate Occurrence: Morbidity (sickness) and mortality Uses scientific method

Advertising and Online Information

Based on scientific evidence! False, old research

Using the Internet Wisely

Be careful and consider sources of Internet information. Consider: •Who or what organization sponsors the site? •Is the information intended to promote sales? •Is there a comprehensive disclaimer such as: "The manufacturer is not responsible or obligated to verify statements."

Type of Epidemiologic studies include

Experiments (such as clinical trials) Cross-sectional studies Cohort (longitudinal) studies Case-control studies

Registered dietitian nutritionist (RDN)

Focus on science, not tradition

Most experiments that involve animals or humans have a treatment group as well as a control group.

Having the two groups allows scientists to compare results.

A real world example is deciding if DARE should still be funded in schools.

How do you let this research affect your decision-making?

Inductive and Deductive Reasoning

Hypothesis-> Deductive Reasoning -> Empirical Observation ->Inductive Reasoning

Correlation

If variable X increases as variable Y increases, there is a positive (direct) association. If one variable decrease as the second variable increases, we label this as an indirect (negative) association. Not able to make remarks about cause and effect based on correlation

Considering the Use of Dietary Supplements

If you are thinking about using dietary supplements: •determine if the supplement is necessary. •consult a physician as soon as you develop signs and symptoms of serious illness. •be wary of claims made about a supplement's benefits and investigate by searching for reliable information.

Observational Epidemiological Studies: Case-control study:

Individuals who have a health condition are compared with individuals with similar characteristics who do not have the condition.

Finding Other Red Flags

Information that promotes a product's benefits while overlooking its risks Vague, meaningless, or scientific-sounding terms Sensational statements without citing references or sources

What we have to trust without scientific research

Intuition, Authority Figures, and Blind Luck

Scientific Knowledge is empirical

It is rooted in objective, tangible evidence. It can be observed time and time again, regardless of the observer.

Mass media

Journalists have good intentions usually, but their reading of the scientific literature may be hampered by their level of knowledge. Beware. Think for yourself.

Sedative, Calming Action

Kama Valerian Dangerous if use with anesthetics

Conventional medicine

Mainstream health care US, other developed nations, major cities in developing world Includes FDA approved medications

Herbal products

May not provide benefits People think their herbal product is helping in the absence of data demonstrating efficiency May be an example of a placebo effect Beware of remedies that are not supported by true experiments with a comparison group.

Examples of observational studies

Naturalistic studies Cross-sectional studies Longitudinal studies Sequential studies - is a combination of (cross-sectional and longitudinal studies) Case-comparison research

Dietary Supplements from FDA perspective

No intention to Prevent Diagnose Treat Cure FDA does not allow claims on dietary supplements such as those for approved medications. No use of these words is appropriate Reduce pain Cure Treat

Nutraceuticals

No real definition

Alternative health care

Not conventical medicine May not have been studied scientifically May not have been proven scientifically to be Safe Effective (useful) Includes: Vitamins, minerals, herbs, chiropractic manipulation, homeopathy, naturopathy, and massage therapy. Many not widely accepted by conventional medicine practitioners Not widely accepted

Peer review

Other scientists scrutinize articles submitted for publication to ensure high quality

Dependent variable

Outcome, endpoint Example: Depression, yes or no

US Food and Drug Administration (FDA)

Oversees regulation of foods and drugs at federal level Goals include barring damaging foods from the market and scrutinizing new drugs Regulates marketing of dietary supplements If harm to consumers from dietary supplements, then FDA alerts consumers FDA can initiate recall of dietary supplements FDA can seize products if warranted FDA works with the approval of medications, such as vaccines, also.

Allergic Reaction

Possible if pollens or other plant parts provoke allergies

Look for Red Flags

Promises of quick and easy remedies Claims that sound too good to be true Scare tactics Personal attacks on registered dietitian nutritionists or conventional scientists Statements about the superiority of certain dietary supplements or unconventional medical practices Reliance on testimonials and anecdotes

Research design video Topics:

Randomization, random assignment, cause and effect, extraneous factors, observational research, correlation, dependent variables, independent variables, replication (repeatability/reproducibility),

Recognizing Other Red Flags

Recommendations based on a single study Information concerning nutrients or human physiology that are not supported by reliable scientific evidence Results disclaimers, usually in small or difficult-to-read print

Ansel Keys

Researcher university of Minnesota focused on dietary fat in relation to heart disease

Experiments

are often conducted on rats or mice before performing similar research on humans. Hallmark of this is researcher controls which study subjects have a particular exposure. Hallmark is that the investigators have control over the independent variable Control is exercised through randomization. All other study designs try to mimic an experiment to the extent that is possible. Experiments are the only study design that allow scientists to make conclusions about causation. We observe changes in an experiment.

Botanicals

are plant material including herbs. Taken by mouth Include Extracts Constituents Metabolites Concentrated substances

Human Intervention Studies1 Placebo effect:

effect that occurs when a person reports a positive reaction to a treatment even though he or she received the placebo. People receiving the placebo are compared to a treatment.

Inductive Reasoning

empirical observations lead to new ideas. Empirical evidence->Larger Conclusion (not always correct) Example Evidence: You notice that all your favorite fruits-apples, bananas, and oranges-are grown on trees. Conclusion: All fruits grow on trees.

Human Intervention Studies2 Double-blind study:

experimental design in which neither the participants nor the researchers are aware of each participant's group assignment.

In vivo

experiments are conducted on whole living organisms, such as lab rodents.

In vitro

experiments or "test tube" experiments are conducted on parts derived from living organisms, such as cells. Inexpensive to have in lab Can carefully control Nutrition uses rodent research Problem may be that tissue removed from organism is not a representation of reality Latin meaning 'In glass,' Occurs in test tube,

Human Intervention Studies1 Placebo

fake treatment, such as a sham pill, injection, or medical procedure. Can be an inert pill or inoculation, as examples Control group receives the placebo

Control group

group being studied that does not receive a treatment Is a comparison group that provides perspective (context) for assessing treatments Without a comparison group, we do not really know if the treatment works. Same as Comparison Group, Is either A proven treatment (such as Paxil), or A fake treatment (a placebo)

Treatment group

group being studied that receives a treatment

Deductive Reasoning

ideas are tested against the empirical world. General Hypothesis -> Conclusion Correct Hypothesis -> New Conclusion Example: Hypothesis: All living things require energy to survive. Ducks are living things. Conclusion: Ducks require energy to survive.

Human Research: Experimental (Intervention) Studies Experimental studies

in humans may be used to obtain information about health outcomes related to specific dietary practices.

Evidence based:

information that is based on results of scientific studies

Laboratory Experiments experiment

is a systematic way of testing a hypothesis (question).

Randomization

is done to make all groups are comparable thus getting around bias. Each study subject has an equal chance of getting into either pill group.

Quackery

is promoting useless medical treatments. •Practicing medicine without proper training is illegal. •However, providing nutrition information and advice without proper training is legal.

Epidemiology;

is the study of disease rates among different population groups, factors associated with the occurrence of diseases, and how diseases spread in a population. a. Data for epidemiological studies may be obtained by physical examinations or surveys. b. These studies are conducted to gain information about the effect of specific dietary practices on health conditions.

Bias

not the same as skewed data

Facts

observable realities

Variable

personal characteristic or other feature that changes and can influence an outcome Examples: Height, weight

Opinions

personal judgments, conclusions, or attitudes that may or may not be accurate

Correlations

pertain to associations, not causation.

Anecdotes

reports of personal experiences

Single-blind study:

researchers know which subjects are in the treatment and control groups.

Today, nutrition experts rely on...

results collected from scientific research (evidence-based results).

When alternative health care practices are used along with conventional medical practices,

the combination is called "integrative" medicine.

Human Research: Epidemiological Studies Epidemiology

the study of the occurrence, distribution, and causes of health problems in populations.

What is a correlation?

•A relationship between variables •Occurs when two variables change over the same period •A direct correlation results when two variables change in the same direction. •An inverse correlation occurs when two variables change in opposite directions. It is important to understand that some changes could be coincidences (unrelated events) and not the result of "cause-and-effect" relationships.

Understanding the Scientific Method In the past, nutrition facts and dietary practices were often based on:

•Intuition •Common sense •Conventional wisdom ("tradition") •Anecdotes (personal reports)

Retrospective

•Means "to look back" •Examines people's past exposures to explain why some people are affected by a condition and not others

Types of Cohort Studies Prospective

•Means "to look forward" •Follows group of healthy people into the future and looks for factors that may have contributed to changes in their health

Dietary supplements include:

•Nutrient pills, •Protein powders, •Herbal extracts, and •Energy bars and drinks.

Alternative health care includes:

•Using supplements, such as herbal products, to treat disease or promote good health; •Chiropractic manipulations; •Homeopathy and naturopathy; •Massage therapy.

Name of supplement Benefits known Risks Known

"Little scientific evidence" "Studies indicate mixed results" "Evidence.........weak" "Potential harm" "May be effective" "Studies support"

Analyzing data, drawing conclusions, and reporting findings

1. Statistical methods are used to test relationships between the variables under study. a. Researchers analyze data, discuss results, and then summarize and seek to publish findings. b. During peer review, investigators who were not part of the study critically analyze the research design and conduct of the study, and they determine whether the results are fairly represented and conclusions are supported by the research. 2. Research bias may occur when the scientists or their funding agencies have certain expectations about the research outcomes; reliable journals require authors to disclose their affiliations and financial support. Such information can help readers interpret the reliability of the findings. 3. Spreading the news a. Media may sensationalize or oversimplify scientific findings. b. Nutrition information presented in the media may be faulty or biased, as it is generally not subject to peer review.

Questioning Claims

1. What is the expertise of the person's making the claim? 2. What might he/she/they gain if the claim is valid? 3. Does the claim seem justified given the evidence? 4. What do other researchers think of the claim?

Becoming a Registered Dietitian Nutritionist

1.Complete an accredited baccalaureate degree program. 2.Complete a supervised professional practice experience. 3.Pass the national registration examination.

1.Popular health-related magazines typically publish articles that have been peer-reviewed. True or false?

1.False Popular health-related magazines typically publish articles that have not been peer-reviewed.

1.Scientists use anecdotes as scientific evidence to support their findings. True or false?

1.False Scientists do not use anecdotes as scientific evidence to support their findings.

1.By conducting a prospective epidemiological study, medical researchers can determine risk factors that may influence health. True or false?

3.True By conducting a prospective epidemiological study, medical researchers can determine risk factors that influence health outcomes.

4.Dietary supplements include vitamin pills as well as products that contain echinacea, ginseng, and garlic. True or false?

3.True Dietary supplements include vitamin pills as well as products that contain echinacea, ginseng, and garlic.

4.In general, registered dietitian nutritionists are reliable sources of food and nutrition information. True or false?

3.True In general, registered dietitian nutritionists are reliable sources of food and nutrition information.

Theory

A complex set of ideas that proposes an explanation.

Human Research: Experimental (Intervention) Studies

A large group of human subjects are randomly assigned to either the treatment or control group.

NHANES

A national survey that has been ongoing since 1999 Representative sample National Health and Nutrition Examination Survey (NHANES)

Hypothesis

A testable prediction that includes an "If, then" statement and tests one piece of theory. Capable of being incorrect. Information->Tested repeatedly.

What Are Dietary Supplements?1

According to the Dietary Supplement Health and Education Act of 1994 (DSHEA), •adds to a person's dietary intake and contains one or more dietary ingredients, including nutrients or botanicals (herbs or other plant materials); •is taken by mouth; and •is not promoted as a conventional food or the only item of a meal or diet. > 50% of Americans take one FDA regulates supplements - differently than medicine Add nutrients or botanicals Botanicals are plant material including herbs. Taken by mouth Include Extracts Constituents Metabolites Concentrated substances Multivitamin/mineral (mv/m) most common dietary supplement Include Pills Protein powder Herbal extract Many dietary supplements are referred to as nutraceuticals.

Becoming a registered dietitian (RD) or registered dietitian nutritionist (RDN)

An RD or RDN has completed a BS degree in an accredited school. Student dietitian nutritionists must also complete a supervised practice program or complete a dietetic internship program after graduation. After completing a supervised practice or dietetic internship, student dietitian nutritionists are eligible to take a national certification exam to become an RD or RDN. RDs and RDNs must continually update their knowledge by obtaining continuing education credits.

Testimonials on anecdotes

Anecdotes provide insight Do not provide proof A lot of advertisement is based on testimonials or anecdotes.

Antibiotic use

Antibiotic use may lead to overgrowth of less friendly bacteria in large intestine Overgrowth may lead to Cramps Diarrhea Death if severe

Testimonials and Anecdotes

Are not proof of a remedy

Inverse Correlation

As a person's fruit intake increases, the percentage of people in that population with hypertension decreases.

Pellagra

Before Dr. Joseph Goldberger's research common thinking was that pellagra was caused by an infectious disease agent Goldberger was physician who Thought patients might have dietary flaw Goldberger that missing dietary components might be foods associated with foods consumed by people with higher incomes especially milk and meat He did experiments in two Mississippi orphanages and among patients in Georgia mental institutions Goldberger gave Georgia mental institution patients milk and meat Patients were cured within a month Research occurred in early 1900s Critics rejected Goldberger's research Goldberger died 8 years before niacin was discovered by Dr. Conrad Elvehjem's team discovered niacin.

Side effects and interactions from dietary supplements

Beware. Use of dietary supplements may lead to: Interactions with other dietary supplements or medications. Dangerous side effects. Example: Aspirin plus ginkgo bilota may lead to increased bleeding. Excess bleeding could be dangerous if patient is taking Coumadin (Warfarin), an anticoagulant prescribed to people with a stroke history, as an example Excess bleeding may stem from Garlic Ginseng Ginkgo bilota Vitamin E

Observational Epidemiological Studies: Cohort study:

Collects information about people, analyzes the information, and measures changes in variables of a group of people over time. Longitudinal study Follow subjects over time Begin as a cross-sectional study Done to find potential causes of disease Example: Framingham Heart study started in 1949 in Framingham, Massachusetts

Integrate Health

Combination of alternative and conventical health care

Confusion and Conflict

Conflicting study results are often the result of different study methods. The science of nutrition is constantly evolving. Old beliefs and practices are discarded and advice changes as nutrition scientists conduct more research and gain greater understanding.

Real world examples

Consult experts in those fields Read from trusted scholarly journals Explore validated websites

Probiotic foods

Contains helpful microbes Beneficial to gastrointestinal (GI system, gut) Helpful microbes are present in the gut.

Case-control studies

Contrast made between people with a condition (cases) versus similar people without the condition of interest (controls, who are a comparison) group Study design to assess causes of disease

Conventional medicine vs. alternative health care

Conventional medicine refers to health care practices that have been scientifically tested and evaluated for safety and effectiveness. Alternative health care refers to health care practices that may or may not have been scientifically tested for safety and effectiveness. Alternative health care practices include the use of dietary supplements, chiropractics, homeopathy, naturopathy, and massage therapy. Combining alternative health care practices with conventional medical care is called integrative health care.

Correlation coefficient -1.0 to +1.0

Correlations that are Indirect, Direct, Positive, Negative

Conflicts of interest

Currently when publish must disclose any conflicts of interest such as owning stock in a company that sells a nutrition supplement in an experiment used in the research Need to know about possible conflicts of interest to keep bias out

Correlational method:

Determine whether two or more variables are related in a systematic way. •No random assignment or manipulation of IV •Calculate correlation coefficient. •Index of the strength of the relationship between two variables of interest •Ranges from +1.00 to −1.00

How are Dietary Supplements Regulated?

Dietary supplements are regulated as foods not as drugs. Supplements bypass strict FDA regulations imposed on drugs. FDA regulates labels on supplements and claims allowed on them.

Become a Critical Consumer of Nutrition Information

Do not assume that information in popular media is reliable. Be wary of ads for nutrition-related products that rely on testimonials and anecdotes. The First Amendment to U.S. Constitution guarantees freedom of speech. •Information or claims do not need to be true. Consumers are responsible for questioning and researching the accuracy (reliability) of nutrition information.

More Tips for Searching Nutrition Information on the Internet

Do not trust a site that attacks the medical or scientific establishment. Avoid sites that provide online diagnoses or treatments. Be wary of commercial sites (*.com), even those with links to reliable sites. Avoid providing your personal information.

Money

Do not waste your money on useless unwarranted or dangerous dietary supplements

Experimental group

Drug X, the new treatment

Pretend study (a clinical trial)

Drug X- New pill for depression Paxil - Depression pill that works (Efficacy has been established.) See these topics below Independent variable Experimental group Control group Placebo

Random sample

Each study subject has an equal chance of being chosen.

Limitations of Epidemiological Studies

Epidemiological studies can show relationships, but cannot establish causation, that is, whether a practice is responsible (the cause) for an effect. Cause ⟶ Effect When two events or observations occur simultaneously within a population, it is not necessarily an indication that one is related to (or causes) the other.

Limitations of epidemiological studies

Epidemiological studies can suggest hypotheses, but cannot establish causation. i. A specific practice causes a particular outcome. b. A correlation is a relationship between two variables that change together over the same period of time. Refer students to Figure 2.5 for descriptions of direct and inverse correlations. c. Correlations may be coincidental in that they occur by mere chance and have nothing to do with the variables being studied.

Nutrition deficiency disease

Examples of deficiency diseases include Scurvy (because vitamin C is lacking) Pellagra (because we now know this disease arises from a niacin deficency) Niacin is a B vitamin

Analyzing Data, Drawing Conclusions, and Reporting Findings

Researchers use a variety of statistical methods to analyze data. These methods allow for finding relationships between variables and health outcomes. Researchers summarize findings and seek to publish scientific articles. Articles submitted for publication in scientific journals undergo peer review before being published. Peer review is a critical analysis of the study and its findings conducted by another group of scientists in the same field. Scientists spend a lot of time testing hypotheses to come up with evidence based truths called conclusions.

Science involves constant updating

Science fields, including nutrition, evolve as new discoveries occur or when traditions thinking becomes discredited

Research Bias

Scientists are expected to collect and analyze data in an honest and objective manner. •Avoid the influences of personal attitudes or biases. •Sources of funding for research may influence scientists involved in the study, making findings less reliable. •Peer-reviewed scientific journals require authors to disclose funding sources.

USP label on products

Seal of approval from U.S. pharmacopeia and consumers but this offers no guarantee

Blinding (same as masking)

Single blind: Only study subject that does not know which treatment they received Double blind: Neither study subject nor the health care team know if the subject received the active preparation Controls bias more than single blind Triple blind: None of the following know if the study subject received the active treatment Study subject Health care team / immediate researchers Study statisticians working with the research group Will have a second set of statisticians who know the treatment and placebo assignments

Skewed data leans to one side or the other side

Some data naturally lean in one direction. Leaning in one direction does not necessarily suggest that something is wrong.

Use dietary supplements wisely

Some herbal supplements are made from plants that have toxic parts or can cause allergic reactions. Herbal supplements may interact with prescription or OTC medications. Consult a physician before using a dietary supplement. Precautions should be taken with the use of all dietary supplements. Dietary supplements are not substitutes for nutritious foods. Report any negative side effects to the FDA's MedWatch program. Highly toxic or cancer - causing (carcinogenic) Comfrey Pennyroyal Sassafras Kana Lobelia Ma hang

Eat nutritious food

Supplements are not a substitute for nutritious food

How are dietary supplements regulated?

The FDA is responsible for the safety and efficacy of medications and other health-related products. The FDA regulates dietary supplements as foods, not as drugs. Most of the strict FDA regulations that apply to the manufacturers of medications do not apply to dietary supplement manufacturers. a. According to the FDA, dietary supplements are not intended to prevent, diagnose, treat, or cure diseases. b. Dietary supplements do not need FDA approval before being marketed. If the FDA determines that a dietary supplement poses a risk to consumers, then an alert and recall of the product is issued.

Scientific Knowledge:

The trademark of scientific research is that there is evidence to support a claim.

Theory vs. Hypothesis Example

Theory: An emotional experience relies on a physiological arousal associated with it. For example, if you walked out of your home and saw a large snake, your heart might race. Brain-> associates this feeling with fear. Hypothesis: A person who is unaware of the physiological arousal will not feel fear.

Reliable Nutrition Experts

There is no standard definition for "nutritionist" or "nutritionalist." Physicians generally do not have extensive education in nutrition. Reliable sources of information include nutrition professors at colleges and universities with nutrition and/or dietetics departments, registered dietitians,* or registered dietitian nutritionists.* * Legally protected credentials

Reliable Nutrition Experts Introduction

There is no standard legal definition for the term "nutritionist." Dietetics is the application of food and nutrition information to help treat many diet-related disorders. A registered dietitian (RN) or a registered dietitian nutritionist (RDN) is a college-trained expert in nutrition. This credential is legally protected.

Independent variable

Thought to be potentially in the causal pathway Occurs before the outcome (dependent variable) Obviously is not the dependent variable There can be many we study through a particular investigation. We manipulate in a true experiment, such a clinical trial for a new drug. Clinical trial to learn if a new pill treatment for depression is efficacious and is safe. (Efficacy pertains to improving the patient's well-being.) For this study there are two arms (Drug X vs. Paxil). The investigators control which drug (the independent variable) each study subject receives. How do they control drug assignment? Through randomization

Becoming a Registered Dietitian Nutritionist (RDN)

Three major professional divisions in dietetics: •Clinical dietetics •Community nutrition •Food systems management

Tips for Searching Nutrition Information on the Internet

Use multiple web sites, especially government sites. Be wary of sites that have personal surveys. Rely on sites reviewed or managed by health professionals. Look for Health on theNet (HonCode) symbol. Do not trust a site that doesnot indicate valid sources.

Non-experimental studies that are observational

We need to do non-experimental studies that are observational when we cannot control independent variables. In observational studies there is no experimental control of any independent variables exercised by the investigators (researchers). We cannot beat one group of kids and not hit another group of kids to assess the impact of physical violence on criminal behavior in these same people when they are adults.

Something is wrong when there is bias.

We seek to minimize bias.

Ask Questions

What motivates the authors, promoters, or sponsors to provide the information? Is the source scientific, such as an article in a peer-reviewed nutrition journal? If a study is cited, how was the research conducted? Does source cite respected nutrition or medical journals or mention reliable experts?

Using Dietary Supplements Wisely

When used properly, micronutrient supplements are generally safe. Herbal supplements may contain toxins. Highly toxic or cancer-causing plants include comfrey, pennyroyal, sassafras, kava, lobelia, and ma huang.

Three possible explanations for correlations

X causes Y. Y causes X. Z causes both X and Y.

Scientific Research

a critical tool to help us navigate the world around us.