Keith Roach, M.D.

DEAR DR. ROACH: Is there any evidence that high doses of vitamin C have decreased or prevented the risk of Alzheimer’s disease? I ask this question because none of the people I know who have developed Alzheimer’s have been taking high doses of vitamin C daily (4,000 to 6,000 milligrams). So, I wonder if this safe, inexpensive, natural remedy, found in health-food stores, could have stopped these tragedies by preventing atherosclerosis in the brain. — A.S.

ANSWER: Many people have had the same idea, and it has been the subject of scientific study. A recent review of the many studies that have been done shows that a diet rich in vitamin C (and other nutrients) is of benefit in helping prevent dementia (including Alzheimer’s). However, taking supplements, even high-dose supplements, is unlikely to have any additional benefit over a healthy diet. Most of the studies showed no benefit of vitamin C compared with placebo. I don’t recommend vitamin supplementation for the purposes of preventing Alzheimer’s disease.

The booklet on Alzheimer’s disease gives a detailed presentation of this common illness. Readers can obtain a copy by writing:

Dr. Roach

Book No. 903

628 Virginia Dr.

Orlando, FL 32803

Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. ROACH: I was considering getting a DNA test in order to get personalized diet recommendations. It’s very expensive. Do you think it’s worth it? — J.B.

ANSWER: In theory, it’s a great idea. Knowing about our precise genetic makeup might allow for personalized recommendations not only on diet, but also on exercise, medication and medical treatments. But in practice, the science is in its infancy. There are a few genes identified that predict better outcomes with one treatment or another and that can identify metabolism of medications, but for the specific indication of choosing the best diet, I don’t know of any good evidence that the diet recommended by the results of genetic testing has any better outcome than a diet that would be recommended for someone in general.

Until there is solid evidence of benefit, I’d recommend saving your money.

DEAR DR. ROACH: I have a family member who is an alcoholic. One year ago, he stopped drinking copious amounts of beer on a daily basis. Since then, he drinks only non-alcoholic beer every day, but continues to consume large volumes of this. Even though it contains less than 0.5 percent alcohol by volume, is this harming him in any way? Is he addicted to it due to the fact that there is still a very small amount of alcohol content? Is it OK for a recovering alcoholic to drink this? — C.R.

ANSWER: Non-alcoholic beer has very, very little alcohol, and at least one brand, Kirin Free, has no alcohol at all. It would be very difficult to become intoxicated with non-alcoholic beer. A typical non-alcoholic beer has about 1.5 grams of alcohol, meaning 10 of these beverages would have the alcohol in one standard drink. Intoxication is unlikely, due to the stomach and liver having the ability to metabolize the alcohol. However, these beverages do contain sugars and calories, so drinking 10 isn’t recommended for overall health.

That being said, your family member has made a large improvement in his health, and I think he would benefit from support, encouragement and congratulations.

EDITOR’S NOTE: Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters or mail questions to P.O. Box 536475, Orlando, FL 32853-6475.