Saturday, July 20, 2013

Vitamins, Snake Oil, and Jenny McCarthy

Since The Atlantic - Health published my piece on Jenny McCarthy, I've gotten a lot of email. A lot of it has been from parents saying: I don't like Jenny McCarthy, and I'm not sure about vaccines, but let me tell you about my child and the dramatic improvements I've seen as a result of dietary changes.

I believe that in many cases with special needs, changing diets can result in changes in behavior and response to other kinds of interventions. I believe that without doing blind studies, the correlation and causation is nearly impossible to tease out, and of course we can't (ethically) really do this kind of blind study with a sufficient sample of children with disabilities. All we can do is try to collect post-intervention data and sort it.

So this morning I read Paul Offit's piece on vitamins. The anti-vax crowd HATES Offit, calling him (I'm not linking to Age of Autism) - "millionaire vaccine industrialist." Now let's not get into the issue that the people selling snake oil to kids with autism are also millionaires, and yes, there are profit margins on all sides. Offit wrote, "Autism's false prophets." He's deep in this fight, much more so than I.

The essay is extremely long and works through the long history of Linus Pauling, vitamin advocate (he claimed that vitamin C cured cancer at one point), and finishes with a terser discussion of lots of recent studies on vitamins. Here's the final point:

Two days later, on October 12, researchers from the Cleveland Clinic published the results of a study of 36,000 men who took vitamin E, selenium, both, or neither. They found that those receiving vitamin E had a 17 percent greater risk of prostate cancer. In response to the study, Steven Nissen, chairman of cardiology at the Cleveland Clinic, said, "The concept of multivitamins was sold to Americans by an eager nutraceutical industry to generate profits. There was never any scientific data supporting their usage." On October 25, a headline in the Wall Street Journal asked, "Is This the End of Popping Vitamins?" Studies haven't hurt sales. In 2010, the vitamin industry grossed $28 billion, up 4.4 percent from the year before. "The thing to do with [these reports] is just ride them out," said Joseph Fortunato, chief executive of General Nutrition Centers. "We see no impact on our business."

How could this be? Given that free radicals clearly damage cells--and given that people who eat diets rich in substances that neutralize free radicals are healthier--why did studies of supplemental antioxidants show they were harmful? The most likely explanation is that free radicals aren't as evil as advertised. Although it's clear that free radicals can damage DNA and disrupt cell membranes, that's not always a bad thing. People need free radicals to kill bacteria and eliminate new cancer cells. But when people take large doses of antioxidants, the balance between free radical production and destruction might tip too much in one direction, causing an unnatural state in which the immune system is less able to kill harmful invaders. Researchers have called this "the antioxidant paradox."

Whatever the reason, the data are clear: high doses of vitamins and supplements increase the risk of heart disease and cancer; for this reason, not a single national or international organization responsible for the public's health recommends them.
So, according to Offit, vitamins are snake oil. There's a shared sense in the battle over knowing, over epistemology, between this issue (so much less heated) and the autism-diet-vaccine world.