How to evaluate health claims

Davis, Robert J. 2008. The Healthy Skeptic.  Cutting through the hype about your health.

This is an overview of a book about health claims.  To try to figure out if a product has whole grains in it, read my article Dishonest Labeling: How to Tell if Something is Really Whole Grain.

This book will help you evaluate health claims of western and “natural” food, supplements, and medicine.  Both often exaggerate, lie, and abuse statistics to convince you to buy whatever they’re selling.

The news media unfortunately gets a lot of its material from manufacturers or trade groups rather than scientific studies, so you always have to be skeptical of what information from newspapers, magazines, and TV.

Nor is the government protecting you, so you can’t assume that what is allowed on labels is true.  In the good old days, the FDA used to only allow health claims backed by significant scientific agreement or an authoritative statement from the National Academy of Sciences.  But now the FDA has yielded to pressures from industry that allows “qualified” claims with limited evidence.

If you’ve been prescribed an expensive drug, or one with potentially life-threatening side effects, Davis suggests you can read the original scientific papers – if you do, I recommend also getting Woloshin’s book “Know Your Chances” to help you interpret it.

Luckily for you, Davis has done the hard work for you and investigates many widely used and prescribed  remedies, such as Lunestra, statins, sunscreen, chemicals, dieting, anti-aging pills, and more.

After reading this book I would never take any medication or supplements without doing in-depth research, because the side effects can range from unpleasant to life-threatening.  And many drugs cost a huge amount of money, yet lower the odds of getting a disease by only 1-2%.  Though you’d never know this from the ads, which might claim 33% — Davis explains the math of how they can make such an outrageous claim and get away with it.

Healthy Food

Davis said many of his friends ask him what foods are the best to eat so they can stockpile these “superfoods”.  Davis tells them there is no such thing as a superfood – just try to eat as wide a variety as possible of fruits, vegetables, whole grains, fish, legumes, and nuts (in moderation).  Avoid red meat, white rice, white bread, and processed or junk food.

The reason there aren’t any “superfoods” is because all food has multiple nutrients that interact with each other and with other food you’ve eaten that affect your body in many ways.  It’s impossible to tease out the effect of individual components.

The FDA now allows “weasel” words to make “structure/function” claims without any proof at all.  So “lowers cholesterol” is not allowed, but the corporation or quack can get around this with “helps maintain healthy cholesterol levels”.  Some other weasel phrases: “maintains heart health” and “provides immune support”.  Unless a product is labeled clearly and unambiguously with a statement that it prevents a condition, ignore the label.  A legitimate label can be found on whole grain products, because several decades of peer-reviewed scientific research has shown whole grains reduce your odds of getting heart disease, stroke, cancer, and diabetes.


I was surprised to learn the decades long Framington findings on high cholesterol applied only to middle-aged people – and that after that the risk of high cholesterol declines. By age 70, there’s no relationship between high cholesterol and death from heart disease.  After 80, low cholesterol is correlated with a higher risk of death from all causes.

And even for the middle-aged, the risks of high cholesterol are exaggerated.

  • A 40 year old man with a high cholesterol level of 240 mg/dL but no other risk factors and no history of heart disease only has a 2% increased risk of heart disease over the next 10 years.
  • The same guy at 180 mg/dL has a 1% risk.
  • For a high cholesterol 50 year old woman who doesn’t smoke or have high blood pressure, there’s only a 1% heart disease risk over the next ten years.
  • A 50-year-old man with normal cholesterol who smokes and has high blood pressure has a 13% chance of heart disease within 10 years, and 22% if he also has high cholesterol.

Bottom line: you can’t view cholesterol levels in isolation.


Statins mainly help those who already have heart disease and only reduce the odds 1.5% for those who don’t.  The main group they help are high risk men between 30 and 69.

Women without heart disease don’t seem to be helped at all.

And statins have some potential bad side effects, including liver damage, muscle weakness, impaired memory and thinking, and possibly cancer (more research needs to be done).  Yet many are calling for statins to be taken preemptively for those in good health.


Your first line of defense is staying out of the sun between 10 and 4 or covering up with a big hat, and long sleeves and pants.  Your last line of defense should be sunscreen.  Sunscreen has not been proven to guard against melanoma and there isn’t much evidence that sunscreen reduces the risk of basal cell carcinoma.  People usually don’t put enough sunscreen on, and worse yet, stay out in the sun longer than the sunscreen will protect them.  Very few are formulated to protect from UVA which is also damaging.

Perhaps a little sun is good for you since it’s hard to get enough vitamin D from food. Adults need roughly 2,000 IU.   Ssalmon has 400 iu’s, one cup of milk (500 iu’s) and you’ve still got to get 1100 iu’s to get somehow.  But you can get thousands of IU’s with some sunshine in 15 minutes or less.

Multi-vitamins and supplements

Recently, several studies of long-term vitamin use did not provide evidence that taking vitamins prevents disease.

Studies that have shown no benefits of multivitamins or other supplements *


Years   of people          Study name

4          35,333           The Selenium and Vitamin E Cancer Prevention Trial

8        161,000           Multivitamin Use and Risk of Cancer and Cardiovascular Disease in the Women’s Health Initiative Cohorts

10          15,000           Physicians’ Health Study II Vitamins E & C in the prevention of cardiovascular disease in Men

232,606           Mortality in Randomized Trials of Antioxidant Supplements for Primary and Secondary Prevention

* Tara Parker-Pope. Feb 16, 2009.  Vitamin Pills: A False Hope?  New York Times.


What’s dangerous is the intermediate chemical perfluorooctanoic acid (PFOA) that is only around during its production, not in your pots and pans (and clothes, carpets, food packaging, and insulation on wires and cables, etc – Teflon is used in many products).

Living a long and healthy life

A landmark study of thousands of healthy people over 70 identified regular exercise, both aerobic and resistance training as “the single most important thing an older person can do to remain healthy”.  Other big factors: staying mentally active, socially connected, don’t smoke or drink alcohol to excess, learn how to handle stress well, get appropriate screening tests, keep your blood sugar and blood pressure levels normal, and eat a diet rich in whole grains, vegetables, fish, fruit, and legumes.  You could do all of the above and still get run over by a truck or be tripped up by your genetic weaknesses, but at least you’ll feel better while you’re still around.


Whatever you’re afraid of, it’s important to put risk into perspective.  The main risk of injury and death you face every day comes from cars.  Every year more than 2,500,000 Americans are injured and 43,000 killed – cars are the main cause of death for those under 35.  So find out the stats before you worry yourself to death.

And above all, ask the right questions:

1)      What kind of a study was it? Order is from least to most credible:

  1. Test-tube research
  2. Animal studies
  3. Population studies (i.e.d diet in Finland versus Japan)
  4. Short-term human experiments
  5. Case-control studies – similar people, but one group has the disease and the others don’t
  6. Cohort-healthy people examined for years (i.e. Framington Heart Study & other long-term studies)
  7. Randomized clinical trials, double-blind

2)      How big was the effect?

  1. For example, the risk of breast cancer for post menopausal drinkers is 1.3, or 30% greater.  1.3 is so small it could be partly or completely due to other causes. Epidemiologists think a relative risk less than 3 is small, especially if there’s no corroboration.  Relative risk of 1 = no increase, 2 = 100%, 3 = 300% etc
  2. Next determine the ABSOLUTE DIFFERENCE IN RISK. If people exposed to substance X have 3 times the chance of disease Y, but only 3 in 1,000,000 exposed get disease Y – so what?

3)      Could the finding be a fluke – chance?

4)      Who was studied?  Men over 70?  If the group isn’t similar to you, you may not need to worry

5)      Is there a good biological explanation of why X happens?

6)      Who paid for the research?

7)      Was it peer-reviewed?

8)      What about other studies?

It’s up to you to investigate health claims.  Below Davis provides to websites with good information, places where there’s no profit motive.

Resources to verify “clinically proven claims”

Nutrition  age/gender daily requirements

Natural medicine and supplements

Natural does not equal safe.  Look for side effects on the package or manufacturers web site.  If there are no warnings, then the product was either not sufficiently tested or the manufacturer is hiding something.

UV protection


Preventive testing

Book: H. Gilbert Welch. 2004. Should I Be Tested for Cancer?  Univ of CA press.


Toxic chemicals:


Steve Woloshin. 2008. Know your chances : understanding health statistics

John Rowe. 1998. Successful Aging.

Thomas Perls. 1999. Living to 100

Ray Moynihan.  2005.  Selling Sickness.  How the World’s Biggest Pharmaceutical Companies Are Turning Us All into Patients.

Steve Salerno.  2005. SHAM.  How the Self-Help Movement Made America Helpless.

Miscellaneous and for conflict of interest issues non-profits with corporate funding

About Alice

I've milled and baked with whole grains for many years, because whole grains are delicious, and white flour is missing the nutrition that protects you from cancer, stroke, heart disease, diabetes and many other diseases. Plus it's a good emergency food.
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