Flashback Friday: Preventing Alzheimer’s with Lifestyle Changes and Diet

It is safe to say that Alzheimer’s disease research is in a state of crisis. For the past two decades, over 73,000 research articles have been published, yet little clinical progress has been made. The reason a cure may be impossible is because lost cognitive functions in Alzheimer’s disease patients are due to fatally damaged neuronal networks, and dead nerve cells cannot be brought back to life. Consequently, replacement with new brain cells—even if it were technically possible, cannot be done without creating a new personal identity. They may live, but is it really a cure if their personality is lost forever?

Developing drugs that try to clear out the plaques from advanced degenerated brain tissue makes about as much sense as bulldozing tombstones from graveyards in an attempt to raise the dead. Even if drug companies figured out how to stop further disease progression, many Alzheimer victims might not choose to live without recognizing family, friends, or themselves in a mirror.

Thus, prevention of Alzheimer’s may be the key. Just as a heart attack or brain attack (stroke) can be significantly prevented, one can think of Alzheimer’s dementia as a ‘‘mind attack.” Mind attack, like heart attacks or strokes, needs to be prevented by controlling of vascular risk factors like high blood pressure and cholesterol, controlling that chronic brain hypoperfusion, the lack of adequate blood flow to the brain over the years before the onset of Alzheimer’s disease, which means a healthy diet, physical exercise, and mental exercise.

Here’s the potential number of Alzheimer’s cases that could be prevented every year in the United States if we could just reduce diabetes rates 10%, 25%, because diabetes is a risk factor for Alzheimer’s. And so is high blood pressure, depression, not exercising your body, smoking, and not exercising your brain. Altogether, a small reduction in all these risk factors could potentially prevent hundreds of thousands of devastated families.

If modifiable factors such as diet were found conclusively to modulate the risk of AD to the degree suggested by this research, then we would all indeed rejoice at the implications.

Up to half of Alzheimer’s cases may be attributable to just these 7 risk factors, and that’s not including diet, just because there are so many dietary factors that they couldn’t fit them into their model, but they acknowledged that diet might be another important modifiable risk factor for AD. In particular, there is growing evidence that dietary patterns, such as the Mediterranean diet, are associated with lower Azheimer’s risk, as well as slower cognitive decline, but which constituents of the Mediterranean diet are responsible?

The traditional Mediterranean diet is a diet high in intake of vegetables, beans, fruit, and nuts, and low in meat and dairy. When they tried to tease out the protective components, fish consumption showed no benefit, neither did moderate alcohol consumption. The two critical pieces appeared to be vegetable consumption, and the ratio between unsaturated fats and saturated fats, essentially plant fats to animal fats.

In studies across 11 countries, fat consumption appeared to be most closely correlated with the prevalence of Alzheimer’s disease, with the lowest fat intake and Alzheimer’s rates in China to the highest fat intake and Alzheimer’s rates in the United States. But this is grouping all fats together.

Harvard researchers examined the relationships of the major fat types to cognitive change over 4 years among 6,000 healthy older women, and found that higher saturated fat intake was associated with a poorer trajectory of cognition and memory. Women with the highest saturated fat intake had 60 to 70% greater odds of worst change on brain function. The magnitude of cognitive change associated with saturated fat consumption was equivalent to about 6 years of aging, meaning women with the lowest saturated fat intake had the brain function of women 6 years younger.

What if one already has Alzheimer’s, though? Previously, this group of Columbia University researchers reported that eating a Mediterranean-style diet was related to lower risk for Alzheimer’s disease, but whether a Mediterranean diet—or any diet for that matter—is associated with the subsequent course of the disease and outcomes had not been investigated, until now.

They found that adherence to the Mediterranean diet may affect not only risk for Alzheimer disease but also subsequent disease course: Higher adherence to the MeDi is associated with lower mortality. And the more they adhered to the healthier diet, the longer they lived. Within 5 years, only 20% of those with high adherence died, with twice as many deaths in the intermediate adherence group, and in the low diet adherence group, within 5 years, more than half were dead, and by 10 years, 90% were gone, 80% were gone, or less than half. And by the end of the study, the only people still alive were those with higher adherence to the healthier diet.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.

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Image credit: Flood G. via flickr. This image has been modified.