Researchers from the University of Munster (Germany) studied 50 healthy, normal- to overweight elderly men and women (average age 60 years), dividing them into three groups: one that restricted daily caloric intake by up to 30%; the second that increased unsaturated fatty acids consumption by up to 20%; and a third group that made no dietary changes (control group.)  The team found the calorie-restricted group demonstrated a 20% average increase in verbal memory scores after 3 months.  As well, the researchers observed that the memory improvements in the calorie-restricted group correlated with decreases in insulin levels and markers of inflammation, including high sensitive C-reactive protein (CRP). 

Previous studies involving lab animal models have suggested that caloric restriction may extend lifespan.  While it is premature to recommend a restricted calorie diet across the board, it is important to manage caloric intake judiciously.  Try to avoid consuming far more calories than you expend in a day: doing so will not only help to offset weight gain, it just might give your memory a boost.