Wednesday, December 10, 2008

We'll get to lower back pain and sex later.

Just take the damned pill and shut up—As we’ve discussed, the three things physicians know the least about are sex, nutrition and lower back pain Today we are going to talk about nutrition--again.

In the last decade, nutrition experts and the media have been swept away with antioxidants, like C and vitamin E. I’ve written about them. They are supposed to prevent coronary heart disease and various forms of cancer. Or not. “Not” is back in vogue. Keep in mind that next year everybody will probably have changed their minds again.

A study in the new issue of the Journal of the American Medical Association concludes that vitamins C and E do not reduce the risk of prostate cancer or any other cancer for that matter. The study, out of Harvard and Brigham and Women’s Hospital, was put out on early release by JAMA because of the results and has stellar credentials. The subjects were members of the Physicians’ Health Study II, a most reputable source, and was randomized, double-blind, placebo-controlled factorial trial. Factorial means high math. This kind of study is the gold standard for science, as the cliché goes. But maybe not.

The physicians, all 14,641 men, 50 years or older, were chosen randomly and either took 400 IU of vitamin E, the standard dose, every other day, and 500 mg of vitamin C every day, or a placebo. The study lasted 8 years.

In the end, there were 1008 confirmed cases of prostate cancer and 1943 total cancers. Vitamin E had no statistical effect on the incidence of prostate cancer or total cancers. Neither did C. Nor was there an effect statistically on colorectal, lung or other site-specific cancers.

In this large, long-term trial of male physicians, neither vitamin E nor C supplementation reduced the risk of prostate or total cancer [the study authors write] These data provide no support for the use of these supplements for the prevention of cancer in middle-aged and older men.

In another study in the same issue, selenium also is useless. Earlier studies showed both were effective.

Well, hold on. The problem with these kinds of studies is the group of subjects. For one thing, the physicians in the study were very well nourished, perhaps more so than many other men. They certainly would be more conscious of health than most, making them different than your average guy, with a whole different life style.

We don’t know what else they ate or what other nutrients they took that might have also had an effect. Whether that changed the results we cannot know. The best news is that there was no apparent harm. Additionally, it is likely that these men had regular PSA tests, more so than non-physicians, which may have skewed the sample, although I don't know if that would effect the results.

Interestingly, the JAMA articles come with a third, an editorial, casting some shadows on prostate studies, so I'm not the only skeptic in the crowd. The editorial does conclude that physicians shouldn't recommend vitamins E or C to patients to prevent prostate cancer.

I have no idea what to tell you. I take 400 IUs of E and 500 mgs of C every day and I’m not dead yet.


azali said...

Great! It looks pretty clever and sweet, i love it so much.


Daro said...

Whe I was in CitGroup (Japan) we had a nutcase for a President. "Hotfoot" I called him. He would dance around on the spot calling us "liars" when we tried to explain anything. The only thing he ever had on his desk was a jar of Omega-3 capsules. I always wondered (jokingly) if it was making people insane. I heard GWB was put on Omega-3 as soon as he became Preznit and we saw HIS performance. Mind you - his mangled English certainly seemed to improve over his reign... Maybe Omega-3 improves the effort performance of idiots but not their judgement-making ability! In which case it should be prescribed only after an IQ test.

Anonymous said...

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Joan Stepsen
Girl geeks