A new review of international data adds to the growing evidence that diet plays a significant role in the risk for Alzheimer’s disease and that populations consuming a Western diet — more meat, sweets, and high-fat dairy products — tend to have the highest rates of the disease.
Alzheimer’s disease is increasing worldwide. Currently, about 42 million people have dementia, with Alzheimer’s disease being the most common type. The greatest risk factors appear to be associated with diet, particularly the excessive consumption of meat, commonly found in Westernized diets.
“Mounting evidence from ecological and observational studies, as well as studies of mechanisms, indicates that the Western dietary pattern — especially the large amount of meat in that diet — is strongly associated with risk of developing Alzheimer’s disease and several other chronic diseases,” said Dr. William B.Grant, author of the review published in the Journal of the American College of Nutrition.
His findings, which come from ecological and observational studies, also show that fruits, vegetables, grains, low-fat dairy products, legumes, and fish are associated with reduced risk of Alzheimer’s disease.
In addition, the researchers investigated the specific risk each country and region faces for developing Alzheimer’s disease based on their associated dietary habits. They compared the Alzheimer’s disease prevalence of 10 countries — Brazil, Chile, Cuba, Egypt, India, Mongolia, Nigeria, Republic of Korea, Sri Lanka, and the United States — to dietary data that had been gathered five, 10, and 15 years before the prevalence data.
They found that when many people in Japan left behind the traditional diet to start consuming a more Westernized diet, Alzheimer’s disease rates rose from one percent in 1985 to seven percent in 2008.
Overall, the findings show that consumption of meat or animal products (excluding milk) had the highest correlations with Alzheimer’s disease prevalence.
Residents of the United States seem to be at particular risk, with each person in the U.S. having about a four percent chance of developing Alzheimer’s disease. Grant says that “reducing meat consumption could significantly reduce the risk of Alzheimer’s disease as well as of several cancers, diabetes mellitus type II, stroke, and, likely, chronic kidney disease.”
“Although the traditional Mediterranean diet is associated with about half the risk for Alzheimer’s disease of the Western diet, the traditional diets of countries such as India, Japan, and Nigeria, with very low meat consumption, are associated with an additional 50 percent reduction in risk of Alzheimer’s disease,” said Grant.