NIH: Prevention of Alzheimer's Disease and Cognitive Decline

The dreaded NIH report

For anyone who has heard about the NIH report from the State-of-the-Science Conference on Prevention of Alzheimer's Disease and Cognitive Decline, things may appear to be a bit gloomy. After all, the report basically says that there is no current evidence of scientific quality that any modifiable factors (diet, exercise, dietary supplements, OTC and prescription drugs, etc) are beneficial in reducing the risk of Alzheimer's, nor of slowing cognitive decline. However grim this report may seem, it indicates that part of the problem comes from the wide variation in how Alzheimer's and cognitive decline are being defined. Essentially this problem stems from a lack of universal agreement on these terms. It does not mean that these factors are completely void of benefits but rather that the science is not strong enough to support them as much as would be needed. In order to gain this support, future research needs to emphasize collaboration and address some of the limitations of existing studies by agreeing on how these terms will be defined and implementing more long-term longitudinal, epidemiological studies.

It's not that we have no idea what causes Alzheimer's. In fact, we know a lot about the risk factors for the disease. However, the truth is, we still don't know enough, as there are many risk factors for Alzheimer's which are quite complicated and interactive. With no single factor being the sole cause of this disease there can be no single measure to stop it. This is what complicates the existing research in the field the most, and is the biggest reason the report appears so grim.

Luckily, there are some general findings which are supported by preliminary studies, that the panel state simply need to be further researched before they can fully support them:

• Cardiovascular Health: Cardiovascular health-related problems, such as high blood pressure, have  consistently been linked with a decline in cognitive functioning. Thus, it's important to keep your heart healthy!
• Diet: A great deal of different diets and supplements have been studied, with mixed results. However, omega-3 fatty acids (most typically found in fish) and adhering to a Mediterranean diet are among those receiving the most support in reducing the risk of cognitive decline.
• Smoking: It should come as no real surprise, but smoking is not recommended, and is a risk factor, not only for Alzheimer's, but many other health conditions as well. While a current history of smoking appears to be most detrimental, it is unclear, as of now, what kind of effect a previous history of smoking has on the risk of Alzheimer's.
• Staying Active: Important in many ways, remaining active by exercising and maintaining a regular social network may help to keep the brain alert and healthy.

Additionally, in their summary of results, the panel stated that the factors associated with an increased risk of Alzheimer's and cognitive decline were things such as the ApoE4 gene (a genetic factor which      cannot be changed), diabetes, and depression. As these last two factors can be partially controlled by things such as stress reduction, adequate sleep, and proper diet, it is likely that they will also provide some benefits in reducing the risk of Alzheimer's. Finally, while there are many measures which were not supported by the NIH report, it's important to keep in mind the effect these measures can have on overall health.

Links to the archived webcast of the conference that took place to develop this NIH report can be accessed here.