Dr. William Grant provided this thorough review of Alzheimer's disease and, as mentioned in his bio below, he published the first paper linking diet to Alzheimer's disease and identifying the major dietary components that are risk and risk reduction factors.
Before you get into the article, I'd like to point out that one of the dietary recommendations that Dr. Grant mentions is fish. While fish would be an extremely healthy food, I would not recommend it eating it to reduce your risk of Alzheimer's because, unfortunately, most all fish is contaminated with mercury and other pollutants. Unless you can verify via lab testing that the fish you are eating is mercury-free, I would not eat it.
However, an excellent alternative to eating fish is taking high-quality fish oil or cod liver oil, either in the form of Carslon's liquid or Living Fuel Omega 3 and E. Eating plenty of fish oil is an important part of preventing Alzheimer's (and a host of other diseases as well).
Following are additional steps you can use to reduce your risk of Alzheimer's. These inexpensive and natural methods can be easily implemented by anyone, and you can keep them in mind as you read the article below:
By William B. Grant, Ph.D. Sunlight, Nutrition and Health Research Center (SUNARC) www.sunarc.org
[Peer-reviewed by Dr. Russell Blaylock]
Inflammation and NSAIDs
Inflammation appears to be one of the risk factors for AD, and is related to free radicals and oxidative stress from beta-amyloid 98 or, transition metal ions 99. One of the ways that fish oil may reduce the risk of AD is by reducing inflammation in the brain.
The use of non-steroidal anti-inflammatory drugs (NSAIDs) to reduce the risk of AD has been studied 100,101 following the finding that those with rheumatoid arthritis had a reduced risk of AD 102. The reader is cautioned that use of NSAIDs including aspirin and COX-2 inhibitors carries the significant risk of gastrointestinal bleeding 103-106.
A recent paper reports that those with H. pylori increase their risk of gastrointestinal tract bleeding by a factor of two to four times 107, so anyone planning to take NSAIDs on a regular basis should be checked for H. pylori. A better policy is to eat in a manner so as to reduce the risk of oxidative stress in the first place, rather than have to treat it later.
Dietary Recommendations
AD is rare in Africa 108 and India 7, but Africans generally consume far fewer calories than would be tolerated in the United States, and Indians are generally vegetarians with high rates of diabetes and heart disease due to large fractions of carbohydrates in their diets. The Mediterranean diet 14,109-115 is associated with a risk of cognitive impairment and AD intermediate between those of Southeast Asia and the United States.
In addition to diet, additional risk reduction can be achieved by taking antioxidant and B-vitamin supplements as well as a few other substances that one can find described in the literature.
Physical Exercise Reduces Risk
Regular physical exercise is another way to reduce the risk of AD. A study in Canada found that those who engaged in high levels of physical activity had half the risk of developing AD of those who did not 116.
Smoking Doubles AD Risk
Smoking was associated with double the normal risk for AD in a cohort study in Hawaii 117. Since those in the United States who smoke generally have poorer dietary habits than those who don't, it could be that dietary factors explain some of the risk. However, since smoking reduces the body's stores of antioxidants, it could well be a direct effect.
Ethnic Differences in AD Prevalence
It is noteworthy that African Americans have the highest AD rate of any ethnic group in the United States 108,118 while Japanese Americans have the lowest 26,119. This result is probably a combination of both genetic and dietary factors. African Americans have a higher frequency of APOE e4 than European Americans, who, in turn, have a higher frequency than Asians.
In addition, there are very likely ethnic differences in diet, with Asian Americans eating less total energy and animal products and more vegetable products than European Americans. Black Americans may eat more convenience foods and fewer fruits and vegetables than European Americans 120, 121. A predisposing gene combined with poor diet is the worst combination in terms of risk for AD.
Prevalence of AD in the United States
Hebert et al. estimated that of the number of people with AD in the United States in 2000 was 4.5 million 122. According to the authors, by 2050 this number will increase by almost three-fold, to 13.2 million.
I have criticized both estimates 123.
The 4.5-million estimate was based on incidence rates in a biracial community, with African Americans making up about 40 percent of the sampled population. The authors used education level to extrapolate the results to the entire United States.
As shown in 124, ethnic origin is a much better way, especially since African Americans have a frequency of APOE e4 that is two to three times that for European Americans. In addition, Hebert et al. seemed to classify nearly everyone with dementia as having AD. That classification is not consistent with what is normally found in Western developed countries 125. In Asian countries, VaD rates are about the same as AD rates since VaD is more related to hypertension, and hypertension is more related to dietary sodium than to dietary fat, and Asian diets are different from Western Developed Country diets.
As for the 2050 estimate, it is likely high as well. If Americans find a way to reverse the obesity epidemic that is sweeping the country, the numbers need not reach that high.
Other studies have also estimated AD prevalence in the United States. The East Boston Study, which estimated 4 million with AD 126, was criticized in 127, who found 2.3 million in 1997, for having incidence values much higher than any other U.S. study. The ecologic study 5 gave an estimate of about 2.1 million with AD in the early 1990s. In my opinion, some prevalence estimates are intentionally inflated in order to persuade Congress to appropriate more funding for AD research.
Diet and Lifestyle Play an Important Role
While genetics plays a role in the risk of developing Alzheimer's disease, diet and lifestyle also play important roles. Since genetics can't be changed, those who would like to reduce their risk of Alzheimer's disease should make lifestyle choices.
For those who want to reduce their risk of AD, the most important thing appears to be related to dietary factors, including fruits, vegetables and moderate intake of fatty fish (or fish oil). Olive oil also appears to be beneficial. In addition, antioxidant and folate supplements would be beneficial. The red wine ingredient resveratrol is also helpful. Finally, keeping body mass index low and keeping both the mind and body active are very helpful.
William B. Grant has a Ph.D. in physics from U.C. Berkeley and has worked at the level of senior research scientist in the fields of optical and laser remote sensing of the atmosphere and atmospheric sciences at SRI International, the Jet Propulsion Laboratory, and the NASA Langley Research Center. He is the author or coauthor of over 60 physics, instrument development, and atmospheric sciences articles in peer-reviewed journals, has edited two books of reprints, and contributed half a dozen chapters to other books. He published the first paper linking diet to Alzheimer's disease and identifying the major dietary components that are risk and risk reduction factors. He has also studied the links between dietary sugars and heart disease and obesity, diet and breast, colon and prostate cancer, and UVB/vitamin D and cancer and autoimmune diseases. He recently retired from NASA and founded Sunlight, Nutrition and Health Research Center (SUNARC) (www.sunarc.org), where he will continue and extend his health research and educational efforts.
William B. Grant has a Ph.D. in physics from U.C. Berkeley and has worked at the level of senior research scientist in the fields of optical and laser remote sensing of the atmosphere and atmospheric sciences at SRI International, the Jet Propulsion Laboratory, and the NASA Langley Research Center. He is the author or coauthor of over 60 physics, instrument development, and atmospheric sciences articles in peer-reviewed journals, has edited two books of reprints, and contributed half a dozen chapters to other books.
He published the first paper linking diet to Alzheimer's disease and identifying the major dietary components that are risk and risk reduction factors. He has also studied the links between dietary sugars and heart disease and obesity, diet and breast, colon and prostate cancer, and UVB/vitamin D and cancer and autoimmune diseases. He recently retired from NASA and founded Sunlight, Nutrition and Health Research Center (SUNARC) (www.sunarc.org), where he will continue and extend his health research and educational efforts.
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