Recently, the NIH asked a large group of scientists to examine the published evidence to determine whether there is anything a person can do to prevent or slow the onset of Alzheimer's disease. Their collective answer was not encouraging. There are plenty of claims to the contrary, including recommendations for mental and physical exercise, dietary additives and supplements as well as an array of herbs and prescriptions drugs. But do these interventions help and what dietary factors or lifestyles might do harm? At the moment, no one knows for sure. The panel of scientists concluded that there is not enough good evidence to make a decisive statement - yeah or nay. So where does this leave aging boomers who are worried about getting Alzheimer's disease? Many physicians - who certainly feel pressure from their patients to offer something, anything at all - continue to encourage patients in the early stages of cognitive decline to engage in healthy activities that will stimulate their minds and bodies in spite of the absence of evidence for any real long term benefits.
However, one of the guiding principles of science is that absence of evidence is not evidence for absence. During the past couple of decades neuroscientists have learned quite a lot about how brain cells die in patients with Alzheimer's disease. Currently, scientists are actively devising ways to prevent the consequences of these toxic processes and have identified nutritional and lifestyle choices that can greatly slow down these toxic cellular processes. My own research, guided by epidemiological findings, has focused upon the potential benefits of coffee and marijuana [see video link below]. The real challenge is proving, using available epidemiological evidence, that any particular intervention can significantly reduce our chances of ever getting Alzheimer's disease. Unfortunately, epidemiology is not a precise business when it comes to humans. We all live complicated lives with complicated diets and have no control over who our parents were. Given this, it's no wonder that it is so hard to prove or disprove that Vitamin E is good or that smoking is bad when it comes to altering our future cognitive decline.
The conclusions reached by the NIH's panel of scientists are spot-on; currently, no single intervention can be proven to increase a person's chances of avoiding dementia. However, I predict that one day we will realize that our true goal is to accumulate lots of relatively minor dietary and lifestyle habits and to maintain them for long periods of time. Many years ago cancer researchers learned that multiple exposures to low levels of specific toxins in our environment are required in order to develop any particular carcinoma. I predict that the same approach will work for drugs and nutrients that are beneficial to our health. Long term exposure to daily doses of fruits, vegetables and grains and regular low level physical and mental exercises may together reach a threshold of benefit that will allow us to die of old age before we suffer significant mental decline. That's the point: ultimately, we may not need to prevent Alzheimer's disease, just slow it down.
Marijuana and Coffee are good for the brain. http://www.youtube.com/watch?v=2uVXs6CY2ps
What to do now?
© Gary L.Wenk, Ph.D. author of Your Brain on Food
(Oxford, 2010); http://faculty.psy.ohio-state.edu/wenk/