Cutting down calories has obvious physical benefits. Now, a study in PNAS shows that it might also improve memory. People who ate 30% fewer calories than usual for 3 months ended up with better verbal memory than they had before they started the diet.

The memory improvement was correlated with decreases in fasting plasma levels of insulin and high-sensitivity C-reactive protein, both of which have been linked to inflammation. Grant Brinkworth, of the Commonwealth Scientific and Industrial Research Organization in Australia, said: “The fact that they saw ... quite strong correlations between memory and insulin, and also inflammation markers, suggests that there may be some physiological underpinning to the effect.” ( NY Times , 27 January 2009.) According to study author Agnes Floel of the University of Münster in Germany, decreased inflammation might help brain function.

In animals caloric restriction has been linked to an increased lifespan. Jeffrey Keller, of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, commented that it may be “...the aging of the body that promotes the aging of the brain.” ( CNN , 26 January 2009.) Rebecca Wood, of the Alzheimer's Research Trust, said: “Many scientists believe there is a link between diet and risk of dementia. This intriguing piece of research adds to the picture of how diet can affect a person's memory.” ( Telegraph , 26 January 2009.)

A spokesman for the British Dietetic Association pointed out that “A drop of 30% in calories is a significant one for someone who is not overweight, and should not be undertaken lightly.” ( BBC News , 27 January 2009.) For some people, however, it might be worth a try. According to Floel, “It's probably a good idea anyway, and you might also do something for your brain.” (CNN.)