Dieting to protect your brain

New evidence has been published this week by a team of researchers led by Veronica Witte and colleagues from the University of Munster in Germany, showing that cutting down the daily calorie intake of elderly people is linked to an improvement in their memory.

Statistics show that we are living in an aging population, and thanks to modern medicine, in general, people are living longer than ever before. But even if our bodies live for longer, our brains don't always do as well, and there is an increasing incidence of neurodegenerative diseases among elderly people. So is there really a brain-healthy diet that people can adopt later in life to help keep their brain in fully functioning state?

Various studies in the past in both people and laboratory animals, have hinted that restricting calories and a diet rich in unsaturated fatty acids could help to protect the brain later in life.

To test the link between diet and memory, Witte and her team worked with a group of 50 people aged between 50 and 80. Some of them were put on a diet for three months that cut their average calorie intake by a third; some were put on a diet rich in unsaturated fatty acids like olive oil and fish oil; and the rest were the control group, with no change in their normal diet.

Before and after the changes in diet, the volunteers had their memories tested. This involved asking them to memorize a list of 15 words. They were then asked to recall as many of those words as possible half an hour later.

When they were tested again after the three month experiment, the group who had a calorie restricted diet remembered more words and made fewer mistakes then they did before. There was no before-after difference in the other volunteers.

The researchers also found that levels of insulin dropped in the blood of the volunteers put on the calorie restricted diet which could help explain the effects on the brain. Lower levels of insulin are thought to lead to greater insulin sensitivity, and improvement in insulin-regulated pathways in our brains which is thought to have a protective role.

Calorie restriction is also linked to anti-inflammatory affects in the body which could help explain how reducing the input of calories can improve memory function.

The results of this study do not necessarily mean that as we get older we should all start starving ourselves, but it does help point the way to a better understanding of what changes take place in our brains as we age and may lead the way to new ways of preventing cognitive decline.