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12 Outline for today

• How to Get Reliable Nutrition Information
• The scientific method
• How to determine if what you read and hear is
  credible
• Supplements
• Next time ?

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Recap of last lecture

• Weight loss diets
• Eating disorders
• Anorexia, bulimia etc.

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Class Bike Ride

• This Sunday at 1000 AM sharp
• Meet at the foot of the Campus
• One and a half hour loop around Wilder Ranch
• Mountain or cross bikes vonly
• Wear a helmet (always)

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NEWS UPDATE

• Obesity is near to overtaking smoking as the No.
  1 cause of death in the United States, CDC
  researchers said on Tuesday, and other research
  shows that its adverse health effects could soon
  wipe out many recent improvements in health.
• A report from the Centers for Disease Control and
  Prevention said that tobacco use was still the
  leading cause of death in 2000, killing 435,000
  people, or 18.1 percent of everyone who died.
• But poor diet and physical inactivity caused
  400,000 deaths, or 16.6 percent of the total, the
  report said.

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Drugs vs. Supplements

• Aspirin vs. Echinacea

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The Dietary Supplement Health and Education Act
(DSHEA) 94

• Classifies vitamins, minerals, amino acids,
  herbal remedies as foods
• Prevents the U.S. FDA from regulating them as
  heavily as additives or drugs
• FDA must prove this food is unsafe before it
  can be pulled from the shelf
• Dietary supplements can be sold without FDA
  approval

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Where to Get Reliable Nutrition Information

• How nutritional knowledge is reliably determined
• How to determine if what you read and hear is
  credible

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Gaining Scientific Knowledge

• Scientific methods
• Observations
• Question
• Testing

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The scientific method

• Observations, questions
• Experiments hypotheses theories
• Controls
• Double-blind studies
• Placebos
• Peer review, publication
• Multiple studies

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History of a typical nutrition-related development

• Hypothesis (based on various observations, ideas)
• Epidemiology
• Designed experiments
• Animal studies
• Human experiments
• Case-control study
• Double-blind study
• Peer Review
• Follow-up studies

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Fig. 1.5
Niacin
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Experiments

• If 1, caretakers would also get the disease.
• 2 Remove moldy corn from diet no effect
• 5 Same for mosquitoes

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Fig. 1.6
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Definitions

• Case control study mini-epidemiological study
• Double blind neither scientists nor patients
  know who is getting placebo and test compound
• Human intervention trials experiments with
  humans to test the hypothesis

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The Web

• One of the marvels of the Internet is that as
  easily as you can receive inaccurate information,
  you can search for and find accurate information.
• The Internet has been a boon to consumers who
  want research and information on voluminous
  issues and topics at the tip of their fingers. It
  has also empowered many people to find health
  information to help them improve their
  well-being. Nevertheless, the ease of Web
  publishing has also given an unregulated forum to
  unreliable sources.

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Nutrients to worry about getting too much

• Vitamin A
• The UL for vitamin A from retinol is 10,000 IU.
  You can find single-nutrient supplements with
  25,000 IU of vitamin A in any health-food store.
  You can put yourself in danger by taking those on
  a daily basis.
• Zinc
• Some single-nutrient supplements exceed the UL
  for zinc.
• Folic acid
• Vitamin D

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Contd
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How you can evaluate nutritional claims

• Scientific support vs. personal testimonials
• Nature of publication
• Lack of supporting evidence
• Credentials of source of claim
• Beware of media sources, advertisements
• Be leery of ads that push a claim for which you
  have to buy their product
• Use common sense and what you learn in this
  class.
• If anyone does come up with a breakthrough it
  wont be kept a secret

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Where to Get Reliable Nutrition Information

• Peer-reviewed journals
• Well known health entities (e.g., American Heart
  Association, American Dietetic Association, etc.)
• Registered Dietitian (RD)

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Tips on Searching for Information on Nutrition

• Try using directory sites of respected
  organizations, rather than doing blind searches
  with a search engine.
• Start with links from the class page
• Ask yourself the following questions
• Who operates the site?Is the site run by the
  government, a university, or a reputable medical
  or health-related association (e.g., American
  Medical Association, American Diabetes
  Association, American Heart Association, National
  Institutes of Health, National Academies of
  Science, or U.S. Food and Drug Administration)?
  Is the information written or reviewed by
  qualified health professionals, experts in the
  field, academia, government or the medical
  community?

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• What is the purpose of the site?Is the purpose
  of the site to objectively educate the public or
  just to sell a product? Be aware of practitioners
  or organizations whose main interest is in
  marketing products, either directly or through
  sites with which they are linked. Commercial
  sites should clearly distinguish scientific
  information from advertisements. Most nonprofit
  and government sites contain no advertising and
  access to the site and materials offered are
  usually free.
• What is the source of the information and does it
  have any references?Has the study been reviewed
  by recognized scientific experts and published in
  reputable peer-reviewed scientific journals, like
  the New England Journal of Medicine? Does the
  information say "some studies show" or does it
  state where the study is listed so that you can
  check the authenticity of the references? For
  example, can the study be found in the National
  Library of Medicine's database of literature
  citations (PubMed link - http//www.ncbi.nlm.nih.g
  ov/PubMed)

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• Is the information current?Check the date when
  the material was posted or updated. Often new
  research or other findings are not reflected in
  old material, e.g., side effects or interactions
  with other products or new evidence that might
  have changed earlier thinking. Ideally, health
  and medical sites should be updated frequently.
• How reliable is the Internet or e-mail
  solicitations?While the Internet is a rich
  source of health information, it is also an easy
  vehicle for spreading myths, hoaxes and rumors
  about alleged news, studies, products or
  findings. To avoid falling prey to such hoaxes,
  be skeptical and watch out for overly emphatic
  language with UPPERCASE LETTERS and lots of
  exclamation points!!!! Beware of such phrases
  such as "This is not a hoax" or "Send this to
  everyone you know."
•  

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• Ask yourself Does it sound too good to be
  true?Do the claims for the product seem
  exaggerated or unrealistic? Are there simplistic
  conclusions being drawn from a complex study to
  sell a product? While the Web can be a valuable
  source of accurate, reliable information, it also
  has a wealth of misinformation that may not be
  obvious. Learn to distinguish hype from
  evidence-based science. Nonsensical lingo can
  sound very convincing. Also, be skeptical about
  anecdotal information from persons who have no
  formal training in nutrition or botanicals, or
  from personal testimonials (e.g. from store
  employees, friends, or online chat rooms and
  message boards) about incredible benefits or
  results obtained from using a product. Question
  these people on their training and knowledge in
  nutrition or medicine.

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• Think twice about chasing the latest headline.
  Sound health advice is generally based on a body
  of research, not a single study. Be wary of
  results claiming a "quick fix" that depart from
  previous research and scientific beliefs. Keep in
  mind science does not proceed by dramatic
  breakthroughs, but by taking many small steps,
  slowly building towards a consensus. Furthermore,
  news stories, about the latest scientific study,
  especially those on TV or radio, are often too
  brief to include important details that may apply
  to you or allow you to make an informed decision.
  

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Check your assumptions about the following

• "Even if a product may not help me, it at least
  won't hurt me." It's best not to assume that this
  will always be true. When consumed in high enough
  amounts, for a long enough time, or in
  combination with certain other substances, all
  chemicals can be toxic, including nutrients,
  plant components, and other biologically active
  ingredients.
• "When I see the term 'natural,' it means that a
  product is healthful and safe." Consumers can be
  misled if they assume this term assures
  wholesomeness, or that these food-like substances
  necessarily have milder effects, which makes them
  safer to use than drugs. The term "natural" on
  labels is not well defined and is sometimes used
  ambiguously to imply unsubstantiated benefits or
  safety. For example, many weight-loss products
  claim to be "natural" or "herbal" but this
  doesn't necessarily make them safe. Their
  ingredients may interact with drugs or may be
  dangerous for people with certain medical
  conditions.

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• " A product is safe when there is no cautionary
  information on the product label."
• Dietary supplement manufacturers may not
  necessarily include warnings about potential
  adverse effects on the labels of their products.
• A recall of a harmful product guarantees that
  all such harmful products will be immediately and
  completely removed from the marketplace."
• A product recall of a dietary supplement is
  voluntary and while many manufacturers do their
  best, a recall does not necessarily remove all
  harmful products from the marketplace.

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