Eating fruits, vegetables, fish and nuts, as well as reducing alcohol intake and red meat, contributes to cognitive abilities and memory improvement. These findings add to existing research linking a healthy diet along with a lower risk of dementia.
The scientists, led by Andrew Smyth, of McMaster University in Hamilton, analyzed the cognitive aspects, memory and feeding habits of a total of 27,860 people from 40 countries over five years: before the study, two years after the study and five years later. The participants were 55 years old and had diabetes or a history of heart disease, stroke or peripheral arterial disease. According to the authors, their objective was to determine the relation between diet and cognitive impairment in population at high risk of cardiovascular disease.
Benefits of anti-inflammatory nutrients
At the start of the study, researchers asked the patients how often they use to eat certain foods, including fruits, vegetables, nuts, soy protein, whole grains, fried foods, alcohol, as well as portions of fish, of meat and eggs.
In cognition tests, the maximum score was 30 points. If the overall result of a patient was reduced by three or more points during the investigation, he was considered showing a decline in his cognitive abilities. During 56 months follow-up period, 4,699 cases of cognitive impairment occurred. However, persons serving a healthier diet, proved a superior level of cognition compared to those eating less healthily food (consumers of more red meat, sweets, and alcohol-among others). Among the 5,687 people with the healthiest diet, 782 (about 14 percent), had cognitive impairment compared to 987 (18 percent of the 5,459) people with less healthy habits.
The authors obtained similar results taking into account factors that could have altered the results, such as physical activity and high blood pressure of the participants. They also found that the basal cognitive level did not influence the results.
Why food may help preserve memory? Smyth’s team said one possibility is that the anti-inflammatory nutrients in fruits, vegetables and fish help preserve mental health. “Also, what advantages the heart tends to benefit the brain too: low blood pressure improves blood flow and strokes are avoided”, says Smyth.
The authors argue that improving the quality of the diet may help reduce the global burden of cognitive impairment.