The Mediterranean diet, which features plenty of vegetables, fruits, herbs, nuts, beans and whole grains, has long been lauded for its heart health benefits. But now a new study shows that it could also improve brain function in elderly people, even when only eaten for a year. According to the research published in the BMJ, following a Mediterranean diet for just 12 months can inhibit production of inflammatory chemicals in elderly individuals that can lead to loss of cognitive function, as well as prevent the development of chronic diseases such as diabetes, cancer and atherosclerosis. For the study, 612 elderly people from France, Italy, the Netherlands, Poland and the United Kingdom has their gut microbiome analysed. Then, 323 of them were put on a special diet, based on Mediterranean principles, for one year, while the rest were asked to eat as they normally would. After 12 months, all of the study participants had their gut microbiome re-analysed. Those who had followed the Mediterranean diet saw beneficial changes to the microbiome in their digestive system. The rate at which bacterial diversity was lost slowed and the production of potentially harmful inflammatory markers was reduced. Furthermore, there was also a growth of beneficial bacteria linked to improved memory and brain function. So-called “keystone” species, critical for a stable “gut ecosystem”, were also boosted, helping to slow signs of frailty, such as walking speed and hand grip strength. “Our findings support the feasibility of changing the habitual diet to modulate the gut microbiota which in turn has the potential to promote healthier aging,” the study authors said.