I know when I tread on people’s cherished beliefs when I get pushback from readers, some of it ,let’s say, quite emotional. But that’s good. It is important that we challenge our beliefs, and if the sacred cows don’t stand up to scrutiny, we should slaughter them (to our Hindu readers – I meant it as a metaphor, honestly).
The October 14 of MedPage Today had an interesting article on the issue of vitamins and other food supplements. Highly recommended. Here are a few choice quotes:
“As the dust begins to settle, physicians interviewed by MedPage Today and ABC News agreed on a bit of simple wisdom –a healthy diet is more important than a fistful of supplements”.
“I had already asked my patients to stop their vitamin supplements four to five years ago, with the exception of those with a deficiency of vitamin D, …pregnant patients [who should get] folate and prenatal multivitamins, or those with cognitive impairment, when I would recommend vitamin B complex”, Albert Levy, MD, a primary care physician in New York, said in an email to MedPage Today and ABC News.”
“And there is sure to be pushback from the largely unregulated dietary supplements market –estimated to be a $20 billion industry –
which has already launched multiple critiques of the latest evidence.”
David Katz, MD, of Yale’s prevention research center told MedPage Today in an interview:
“What we had was a notion that this was an insurance policy. Many people don’t eat the way they ought to, so they are not getting the optimal doses of nutrients from foods. Instead, we can rely on on a pill that ought to do some good, and certainly couldn’t do you harm. That was the thinking. But more studies suggested that health outcomes in patients taking multivitamins appear to be slightly worse”.
“Considering the weak basis for recommending multivitamins in the first place”, Dr Katz said, “when you combine that with evidence that maybe it could hurt, the rationale for making routine use of multivitamins goes away”.
Which Supplements are Supported?
“That’s not to say supplements shouldn’t be used at all, Katz said. He recommends omega-3 fatty acids and vitamin D for most of his patients, plus calcium for women. Prenatal vitamins and folic acid supplementation are also on the list. There is evidence behind those supplementations, he said. The GISSI trial found cardiovascular benefits for omega-3. Study after study has shown that the majority of Americans are deficient in vitamin D, and the supplement study included more positive finding for folic supplementation around the time of conception. As for the rest of supplement lot- give them only in the face of deficiencies, Katz said”.
Why don’t they Work?
“It’s not clear why these vitamins don’t do why they’re expected to do, and researchers are actively looking into why. [Patients] should stop trying to look for health in a pill, Lee green, MD, of the University of Michigan, said in an email. Health is not found in pills. It’s found in good food and regular exercise. There is something in our psyche that makes us want to believe in magic, and that desire to believe has focused on vitamins.”
So far for MedPage Today.
The politics of dietary supplements
So with all this evidence, how is it that this industry is unregulated? How could they mislead the public for so many years without a peep from the FDA? Chalk this one up to our peculiar form of democracy.
The state of Utah is the home for the multibillion dollar industry, and they own the influential senator from Utah, Orrin Hatch. They funnel millions of dollar to the coffers of his PAC, ensuring that their guardian angel stays on duty in Washington D.C. When the evidence mounted that certain supplements are not just useless, but outright toxic, certain senators’ onsciences began to bother them; they proposed to put the supplements under the FDA jurisdiction. Hatch’s son, a lobbyist for the industry,”worked” the Congress, but failed to derail the bill coming before the senate. So Hatch Senior pulled the ultimate senatorial weapon: he promised to filibuster to death the FDA authorization bill if the supplement industry is not exempted from any future regulation. And this is why we are where are today. Shouldn’t the “occupy Wall Street” protesters widen it to “Occupy D.C.” as well?
So will all this evidence change minds? Will there be a massive desertion of the multivitamin cult by consumers? I doubt it. We are behaviorally addicted to our multivitamin pills. We fear that we are exposing ourselves to disease, or at least to sub optimal health. I found myself reaching for the multivitamins this morning, and had to argue with myself that it’s time to kick the habit. I was successful; I am sure tomorrow is going to be a lot easier. Just like any going-clean process. Try it.
Reader reactions and responses:
Our post of October 13 on dietary supplements generated quite a few comments and questions. Some of them are of general interest, so rather than replying to them individually I decided to reply in this posting.
Juanito had several questions. One of his concerns was my emphasis on peer-reviewed publications. He is asking whether they are “clean”, by which he means untainted by commercial considerations. Papers are reviewed on multiple levels. First to see the manuscript and vet its acceptability is the editor of the journal. The editor’s considerations are primarily suitability and newsworthiness. To cite an extreme example, a paper on nuclear physics is not suitable for publication in a journal of psychology. Likewise, a study that merely confirms multiple previous studies is not newsworthy enough for weekly journals like Science or Nature, that report on cutting edge research. The manuscript is then sent to a panel of reviewers, usually three. The identity of the author is kept anonymous to prevent bias. The reviewers are usually academic, and expert in the subject matter of the paper. Sometimes, a reviewer can guess at the identity of the author by the type of experiment, style of writing or opinions, and this is a possible weakness in the process. On the whole, though, the integrity of the review process is quite good; some Nobel Prize winners are known to have had their papers rejected for poor experimental design, faulty statistical analysis, unwarranted conclusions, etc. As you can see, great care is taken to keep the process “clean”, and rigorously vetted. This is why a peer-reviewed paper has the “seal of good housekeeping”.
Juanito also asked about calcium prescribed by his gastroenterologist, his primary care physician prescribing calcium “for another reason” in addition to multivitamins, and his ophthalmologist prescribing fish oil for dry eye symptoms. Some papers claim that calcium inhibits intestinal adenomatous polyps (polyps that can be pre-cancerous). The evidence is mainly pre-clinical (lab and animal studies). In terms of human clinical trials, a large observational study of white post- menopausal women showed that calcium supplements reduced death rate of all causes. The recent study showing increased risk of mortality caused by multivitamins (archives of Internal medicine, Oct.10, 2011) also showed reduced mortality in people taking daily calcium supplements.
The evidence for fish oil (specifically n-3 omega fatty acids) for the treatment of dry eye syndrome is pretty shaky. Some research links eating more fish with lower risk of dry eye syndrome in women. The only effect that fish oil has been convincingly shown to have is reduction in serum triglycerides. So regardless of its effect on your dry eyes, it may be good for your lipid profile. My preference –a fish dinner once or twice a week, but this may be because my wife is a great cook.
Jim Salber asked about calcium for bone health. Although it makes intuitive sense, recent studies actually showed no effect of calcium supplements on bone density. But as I said before, it may be good for prevention of intestinal polyps .
Taking a ”minerals” supplement is more complicated: it depends what kind of minerals are included. For instance, the same study showing increased mortality risk in subjects who take multivitamins also showed increased mortality in people who take magnesium, zinc, iron, and copper supplements. So unless your doctor actually tested the blood levels of these minerals and found deficiencies –there is no reason to take them.
Fish oil for the brain is a claim without good evidence. The only supplement that may have an effect on cognition is B complex. It was shown that low levels of B12 may contribute to cognitive problems for older adults. Older people also suffer from reduced absorption of dietary B12. So supplementation is indicated if your serum level is low.
Joy Slaughter is asking if her vitamin supplements may be responsible for her atrial fibrillation. The short answer is most probably not. I don’t know of any evidence that multivitamins have this adverse effect.
Bottom line: supplements are indicated if and when a deficiency is diagnosed. There is good evidence for vitamin D (600 mg/day for ages 1-60, 1000 mg/day for age >60), fish oil (3 grams or less per day), and vitamin B12 in the elderly if indicated by changes in cognition. In the minerals group, calcium supplementation is the only one with evidence of potential benefit in prevention of intestinal adenomatous polyps.
Taking multivitamin pills used to be thought of as an insurance policy; this is not true anymore -they are at best bad for your pocketbook, and at worst bad for your health.