A recent study has reportedly claimed that diets high in calories and animal fat are associated with increased rates of Alzheimer’s disease (AD) in Japan and eight other countries. William Grant, "Trends in Diet and Alzheimer’s Disease During the Nutrition Transition in Japan and Developing Counties," Journal of Alzheimer’s Disease, September 2013. Using nutrition data supplied by the U.N. Food and Agriculture Organization, Sunlight, Nutrition and Health Research Center Director William Grant compared AD trends in Japan with changes in national dietary supply factors, alcohol consumption and lung cancer mortality rates over 25 years, in addition to comparing AD trends in eight developing countries with changes in national dietary supply factors over the same time period.

The results evidently showed that in Japan, "alcohol consumption, animal product, meat and rice supply, and lung cancer rates correlated highly with AD prevalence data, with the strongest correlation for a lag of 15-25 years," while the eight-country study found that "total energy and animal fat correlated highly with AD prevalence data, with a lag of 15-20 years." As Grant thus concluded, these findings suggest that "the rate of AD and dementia will continue to rise as estimated… unless dietary patterns change to those with less reliance on animal products or new ways are found to reduce the risk of AD." See Journal of Alzheimer’s Disease Press Release, September 22, 2013.