Expert: Mary Gordon - 4/10/2007

Question
What is the incidence of these diseases in other countries of the world?  If there is a higher incidence in some countries there may be a correlation with diet or something else to cause it to be lower.

Answer
Although there are stats comparing countries, I don't think they are reliable.

Even in North America today, dementia in the elderly is often poorly investigated by medical professionals. All too often, the underlying cause of the cognitive problems is never diagnosed - so although we may know the person had a dementia, its not possible to know what it was from. You may know there are many illnesses that cause memory and cognitive decline in the elderly. All too often people accept confusion in older people as something to be expected, so no one can say with any confidence whether they had Alzheimer's or something  else. That fact makes it hard to get accurate statistics, not just in North America - but from other countries.

In many cultures, senility in the old can be seen as normal, and the person is cared for by their family, and not taken to a doctor about their condition, much less seen by a specialist for formal examination to rule out everything else it could be.

The other thing to realize about Alzheimer's itself, is that it really IS a disease of privilege in many ways, given that the longer you live, the higher your odds of getting it. So, if you have a very healthy population with good nutrition and medical care and a long life expectancy,  you are going to see a much higher rate of Alzheimer's than in a population where the average lifespan is shorter.  In every country where life expectancy has increased, so has the incidence of Alzheimers.

On top of everything else are racial differences. For example, the second most common cause of dementia in North America tends to be multi-infarct dementia, caused by an endless series of small strokes or blockages. However, in China and Japan, multi-infarct dementia is more common than Alzheimers's. Is the difference diet (or some other lifestyle factor), is it  geography, or perhaps genetics. I don't think we can answer any of those questions at that point - mostly because we don't yet really understand what triggers Alzheimer's.

The best thing any of us can do to live to a happy old age with all our marbles intact is do exactly what doctors have been telling us forever (advice that few of us listen to) - take good care of ourselves - exercise, don't smoke, don't drink too much, keep our weight under control, keep our blood pressure down,  avoid stress, and eat right.

So yes, eat a healthy diet. It can't do you anything but good in the bigger picture.

Here is a good article
http://www.medscape.com/viewarticle/466037

Mary G.