Eating less can help older adults improve their memory and prevent or delay the onset of Alzheimer''s, suggests a new study.

London, Jan 27: Cutting on calorie intake increases lifespan in mice, reduces the risk of heart disease in people and boosts cognitive ability in elderly animals, it has been shown.

To see if the cognitive benefit held for people, Agnes Floel and team, at the University of Munster in Germany tested the short term memory of 50 people with an average age of 60, who were overweight, but not obese, and then got one-third to eat 30 percent fewer calories than normal each day.

Post three months, the dieters scored 20percent higher on the test than they had before the diet, recalling on average 12.5 words compared to 10.5.

"Two words may not seem like much, but it''s more than the difference between people under 30 and above 50," says Floel.

Those who did not go on the diet showed no change, reports New Scientist.

The dieters had lower levels of glucose and insulin in their blood which previous studies have linked to greater neural function, the study found.

The study has been published in Proceedings of the National Academy of Sciences.