People who eat plenty of fruit and vegetables, wholegrains and fish, while cutting back on red meat, sweets, fried foods and refined foods, preserve their memory and thinking ability even as they age, explains the first study, carried out by McMaster University in Hamilton, Ontario, Canada and published on 6 May in the journal Neurology.

The researchers found that among 28,000 older adults from 40 countries, those who reported "eating healthily" were less likely to show declines in memory and attention, maintaining their mental abilities over the years. Compared with the group of older adults who consumed red meat and sweets, the risk of mental decline for the first group was approximately one quarter lower.
According to researcher Andrew Smyth, who led the research team, while acknowledging that people with healthy eating habits may be better educated, slimmer, more inclined to physical activity and less likely to smoke than those who pay less attention to their diet, the study nonetheless makes it clear that a healthy diet can reduce the risk of cognitive decline.

On the other side of the world, a Spanish study, published on 11 May in Jama Internal Medicine, demonstrated that adding extra virgin olive oil and walnuts to the Mediterranean diet — rich in fruit, vegetables, fish and wholegrains and low in red meat — can help keep the mind sharper and more active. The Spanish researchers found that older adults who follow this type of diet show improvements in thinking and memory, something not observed in the group of older adults whom the researchers asked to follow a low-fat diet.

"The onset of age-related mental decline can be delayed with a healthy diet rich in foods with high antioxidant power, such as extra virgin olive oil and walnuts," stated Dr Emilio Ros of the Hospital Clinic in Barcelona. "Since the average age of participants was 67 when the trial began, we can say that it is never too late to change our diet, in order to maintain or even improve brain function," concluded Ros.