Wednesday, March 21, 2012

Vitamins Are Not Good For You

I sent my "Tevye Channel" post to a physician friend who is also a medical researcher.  (I have mentioned him from time to time.)  A brilliant guy, and not afraid to ask my favorite question "What if the opposite is true?" or be skeptical about those who think themselves skeptics.  He mentioned his running theory that vitamins are bad for you (Note: he is big on fish oil however), remembering my claim that exercise is bad for your health.  He put in the following recent research evidence: (italics mine, if you want to skip to that point.)

Antioxidants May Not Help Patients With Alzheimer's.
MedPage Today (3/19, Phend) reported, "Antioxidant supplements don't appear
to have an impact on cerebrospinal fluid (CSF) biomarkers related to
Alzheimer's disease," according to a study published in online in the
Archives of Neurology. "The combination of vitamin E, vitamin C, and
alpha-lipoic acid did not lower levels of the amyloid and tau proteins that
make up the plaques and tangles seen in the brain with Alzheimer's
disease," researchers reported. Notably, "the popular antioxidant coenzyme
Q (CoQ) had no significant impact on any CSF measures in the Alzheimer's
Disease Cooperative Study antioxidant biomarker trial."

        Researchers "gave antioxidant supplements to 78 patients with
Alzheimer's disease who were part of a study funded by the US National
Institute on Aging," HealthDay (3/19, Reinberg) explained. "The patients
were placed into three groups" where "one group received daily doses of
vitamin E, vitamin C and alpha-lipoic acid," the "second group was given
coenzyme Q (a compound made naturally in the body to protect cells from
damage) three times a day," and "the third group received a placebo. After
16 weeks, 66 patients had their cerebrospinal fluid analyzed."

        Medscape (3/19, Brooks) reported, "The antioxidant combination led
to a relatively small reduction in CSF F2-isoprostane level, suggesting a
decrease in oxidative stress in the brain, but it was also associated with
accelerated cognitive decline on the Mini-Mental State Examination (MMSE)."
The authors said, "It is unclear whether the relatively small reduction CSF
F2-isoprostane level seen in this study may lead to clinical benefits in
AD," and noted that "the more rapid MMSE score decline 'raises a caution
and indicates that cognitive performance would need to be assessed if a
longer-term clinical trial of this antioxidant combination is considered.'"
Additionally, they said, "These results do not support further clinical
trial development of CoQ in AD." Also covering the story is Reuters (3/20,
Accelerated cognitive decline on a standard, concrete, instrument.  Ouch.

I made my usual encouraging but banal remarks to such things.  He elaborated in his return email.  I was going to summarise, but he speaks for himself better than I could for him.
  Vitamins are likely to cause unexpected consequences when you take them in
doses never seen in nature (almost always the case) thinking there is no
such thing as too much vitamin (almost never the case) to prevent a disease
that is separated from the biochemical function of the vitamin by several
incompletely understood causal relationships.  Another way to look at it is
that you're using a very precise tool like a scalpel, and by means of large
doses, applying it to your body with the force and precision of a grenade
launcher.  There's recent evidence on iron supplementation for example with
mortality increases...

We in medicine often fall prey to the hubris that comes from success
stories such as scurvy and vitamin C. The allure of preventive medicine and
the conceit of understanding some biochemistry are pleasant diversions from
the ugliness of complexity and a lack of clinical outcomes data.

1 comment:

Jan said...

The AD thing doesn't surprise me, I think health nuts and their doctors have jumped the shark with the 'anti-oxidants will cure everything' meme. The iron supplement thing worries me though, as I have to take them for chronically low blood ferritin levels. But hey, what fun would life be without something to worry about?