I recently read that Zinc can contribute to Alzheimers disease. It appeared in The Wall Street Journal. Does anyone know more about this and what medical journal this appeared. Most ophthalmoligists are now advising the taking of Zinc with antioxidant vitamins (at least down here in Florida) My medical doctor would like more info. since many of his patients are using Zinc.
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Answered by Richard E. Gans, M. D. (xx102@ofcn.org)
Sometimes in medical practice, the more we think we know, the less we truly know.
In recent years, there has been increasing evidence, based upon population studies, to suggest that dietary supplements of zinc, selenium and anti-oxidants might help to slow the progression of macular degeneration. Despite limited scientific data to prove their efficacy, feelings that these supplements were not harmful prompted many ophthalmologists to suggest these supplements to their patients who are at risk to develop macular degeneration.
Recently, data has begun to surface, questioning the safety of dietary zinc supplements in some specific patient groups. The reference to which you refer, appeared in Science (Vol. 265. September 2, 1994) In it, there are references to studies that showed that zinc supplements caused rapidly progressive dementia in patients with Alzheimer's Disease. An in vitro (test tube) study also showed that high levels of zinc caused clumping of beta amyloid, similar to amyloid plaques found in the brains of people with Alzheimer's Disease.
To sum up what is currently known:
1. Dietary zinc MAY help to slow the progression of macular degeneration.
2. Dietary zinc MAY worsen the dementia associated with Alzheimer's Disease.
3. There is no evidence to suggest that zinc is the cause of Alzheimer's Disease.
4. None of these issues has been satisfactorily proven by prospective clinical studies.
5. A great deal of research will be necessary to sort out the good vs. bad effects of zinc.
The article in Science (Vol. 265. September 2, 1994. p. 1365) quotes Rudolph Tanzi, a researcher at Massachusetts General Hospital as saying: "A decade ago . . . research proposing a link between Alzheimer's and aluminum -- a link now regarded as highly questionable -- caused many people to throw aluminum and Silverstone-coated pans in the garbage. Tossing out cookware might be expensive, but it's not dangerous. But removing zinc, a metal that is important to health, from one's diet could have serious repercussions."
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Copyright, 1994. Richard E. Gans, M.D.
A RICHARD E. GANS, M.D. 11
A A OFCN Primary Sysop, The Eye Clinic 111
AAAAA xx102@ofcn.org 11
A A A C A D E M Y O N E 1111
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