Tag Archives: public health

Why You Should Not Stop Taking Your Vitamins

pale-woman-taking-vitamins_123rf.com_Do vitamins kill people? How many people have died from taking vitamins? Should you stop your vitamins?

It depends. To be exact, it depends on the quality of the science and the very nature of scientific research. It is very hard to know things exactly through science. The waste bin of science is full of fallen heroes like Premarin, Vioxx and Avandia (which alone was responsible for 47,000 excess cardiac deaths since it was introduced in 1999).

That brings us to the latest apparent casualty, vitamins. The recent media hype around vitamins is a classic case of drawing the wrong conclusions from good science.

Remember how doctors thought that hormone replacement therapy was the best thing since sliced bread and recommended it to every single post-menopausal woman? These recommendations were predicated on studies that found a correlation between using hormones and reduced risk of heart attacks. But correlation does not prove cause and effect. It wasn’t until we had controlled experiments like the Women’s Health Initiative that we learned Premarin (hormone replacement therapy) was killing women, not saving them.

New studies “proving” that vitamins kill people hit front pages and news broadcasts across the country seemingly every day.

Paul A. Offit’s recent piece in The New York Times, “Don’t Take Your Vitamins,” mentioned a number of studies that suggested a correlation between supplementation and increased risk of death. Offit asserts, “It turns out … that scientists have known for years that large quantities of supplemental vitamins can be quite harmful indeed.” The flaws in the studies he quoted have been well documented. Giving large doses of a single antioxidant is known to set up a chain reaction that creates more free radicals.

But many studies do not prove anything. Science is squirrelly. You only get the answers to the questions you ask. Many of the studies that are performed are called observational studies or epidemiological studies. They are designed to look for or “observe” correlations. Studies like this look for clues that should then lead to further research. They are not designed to be used to guide clinical medicine or public health recommendations.

All doctors and scientists know that this type of study does not prove cause and effect.

Why Scientists Are Confused

At a recent medical conference, one of most respected scientists of this generation, Bruce Ames, made a joke. He said that epidemiologists (people who do population-based observational studies) have a difficult time with their job and are easily confused. Dr. Ames joked that in Miami, epidemiologists found everybody seems to be born Hispanic but die Jewish. Why? Because if you looked at population data in the absence of the total history and culture of Florida during a given time, this would be the conclusion you would draw. This joke brings home the point that correlation does not equal causation.

Aside from the fact that they fly in the face of an overwhelming body of research that proves Americans are nutrient deficient as a whole and that nutritional supplements can have significant impact in disease prevention and health promotion, many recent studies on vitamins are flawed in similar ways.

How Vitamins Save Money and Save Lives

Overwhelming basic science and experimental data support the use of nutritional supplements for the prevention of disease and the support of optimal health. The Lewin Group estimated a $24 billion savings over five years if a few basic nutritional supplements were used in the elderly. Extensive literature reviews in the Journal of the American Medical Association and the New England Journal of Medicine also support this view. Interventional trials have proven benefit over and over again.

The concept that nutritional supplements “could be harmful” flies in the face of all reasonable facts from both intervention trials and outcome studies published over the past 40 years. For example, recent trials published within the last few years indicate that modest nutritional supplementation in middle age women found their telomeres didn’t shorten. Keeping your telomeres (the little end caps on your DNA) long is the hallmark of longevity and reduced risk of disease. A recent study found that B12, B6 and folate given to people with memory loss prevented brain atrophy that is associated with aging and dementia. In fact, those who didn’t take the vitamins had almost ten times loss of brain volume as those who took the vitamins.

A plethora of experimental controlled studies–which are the gold standard for proving cause and effect–over the last few years found positive outcomes in many diseases. These include the use of calcium and vitamin D in women with bone loss; folic acid in people with cervical dysplasia (pre-cancerous lesions); iron for anemics; B-complex vitamins to improve cognitive function; zinc, vitamins C and E and carotenoids to lower the risk of macular degeneration; and folate and vitamin B12 to treat depression. This is but a handful of examples. Fish oil is approved by the FDA for lowering triglycerides and reduces risk of heart attacks and more. There are many other studies ignored by Offit in his New York Times piece.

Stay tuned for Part 2!

 

Originally published on my website, DrHyman.com.

Health Benefits of the “Mildly Overweight”: Can We Handle Subtlety in Scientific Reporting?

Screen Shot 2013-05-31 at 11.34.57 AMIf researchers discovered that, contrary to popular belief, carrying a few extra pounds might not actually be that bad for our health – that it could in fact be better for long-term health than being a size zero – would you want to know? Our guess is: Yes, absolutely.

Now imagine a doctor who has worked all his life to combat obesity and promote healthy lifestyles, who has tirelessly preached the dangers of excess weight throughout his career. You can understand that a new report such as this would deeply trouble him – that he might even take steps to prevent its dispersal to the general public.

This is not a theoretical tale from some overly dramatic medical soap opera. The report is real: A review of 97 independent studies, including nearly 3 million people, headed by Katherine Flegal, an epidemiologist at the National Center for Health Statistics. Published earlier this year in the Journal of the American Medical Association (JAMA), Flegal’s study revealed the surprising news that what is medically classified as “overweight” is actually associated to lower mortality rates than both obesity and normal weight.

This of course challenges basically everything we thought we knew about weight and health (apart from the consensus that obesity unhealthy.) And this is where Walter Willett, chair of the Harvard School of Public Health’s nutrition department, enters the picture. A highly quoted nutrition expert, Willett’s research focuses on diet and lifestyle habits (namely alcohol, red meat, birth control pills, and artificial sweeteners, among others) and their correlations with different forms of cancer. Willett is now the subject of considerable public scrutiny for expressing some less-than-professional opinions on Flegal’s report. In an interview with NPR, Willett commented, “This study is really a pile of rubbish, and no one should waste their time reading it.”

Unfortunately, dismissing such a comprehensive report as Flegal’s as “a pile of rubbish” might have been the worst move of Willett’s career. Science is, by definition, a critical and collaborative field. Its findings have power and influence in our society because we trust the scientific method; and we trust it because, presumably, the research is tested, challenged, and peer-reviewed. Willett’s comment reveals a fundamental disregard for this equilibrium, no matter how noble his intentions.

There is certainly something to be said for simplicity in scientific reporting. If the general public needs to hear that excess weight leads to heart disease, diabetes, and other chronic illness in order to adopt healthy eating and lifestyle habits, then maybe we can believe that’s all researchers are responsible for reporting. If, on the other hand, we trust that the general public is thoughtful and discerning enough to consider shades of grey and make informed lifestyle decisions, then it would be dangerously irresponsible for scientists to censor their findings. The obsession with weight in our culture has undermined the promotion of healthy body image, self-esteem, and eating habits, particularly among teenagers and women. If Flegal’s report could introduce a bit of breathing room, then it is worth the effort that may need to go into explaining and elaborating on those pesky shades of grey.

What do you think? Can we handle subtlety in scientific reporting? Tell us your thoughts in the comments section below!

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