From William Grant, Sunlight, Nutrition and Health Research Center
While you highlight decreasing dementia rates in England and Wales (11 January, p 32), in China, Japan and the developing world the rates are increasing. For example, in Japan, Alzheimer’s disease rates for those over the age of 65 increased from 1 per cent in 1985 to 7 per cent in 2008.
According to my own research, there is a correlation between the transition from a traditional Japanese diet to a Western one, with a 15 to 25-year lag. Higher food consumption and obesity rates may explain increases in developing countries.
San Francisco, California, US
