Eating a heart-healthy diet in young adulthood — one rich in fruits and vegetables, moderate in nuts, fish and alcohol, and low in meat and full-fat dairy — is associated with better cognitive performance in middle age, according to a new study.
“Our findings indicate that maintaining good dietary practices throughout adulthood can help to preserve brain health at midlife,” said study author Claire T. McEvoy, Ph.D., of Queen’s University Belfast in Northern Ireland.
The study included 2,621 people who were an average age of 25 at the start of the study and were then followed for 30 years. They were asked about their diet at the beginning of the study and again seven and 20 years later.
Cognitive function was tested twice, when they were about 50 and 55 years old, according to the researchers.
Dietary patterns were evaluated to see how closely they adhered to three heart-healthy diets: The Mediterranean diet, the Dietary Approaches to Stop Hypertension (DASH) diet, and diet quality score designed as part of a study called the CARDIA a priori Diet Quality Score, or APDQS.
The Mediterranean diet emphasizes whole grains, fruits, vegetables, healthy unsaturated fats, nuts, legumes, and fish and limits red meat, poultry, and full-fat dairy.
The DASH diet emphasizes grains, vegetables, fruits, low-fat dairy, legumes, and nuts and limits meat, fish, poultry, total fat, saturated fat, sweets, and sodium.
The APDQS diet emphasizes fruits, vegetables, legumes, low-fat dairy, fish, and moderate alcohol, and limits fried foods, salty snacks, sweets, high-fat dairy, and sugar-sweetened soft drinks.
For each diet, study participants were divided into one of three groups — low, medium or high adherence score — based on how closely they followed the diet, the researchers explained.
The researchers found that people who followed the Mediterranean diet and the APDQS diet had less decline in their cognitive function at middle age between ages 50 and 55.
People with high adherence to the Mediterranean diet were 46 percent less likely to have poor thinking skills than people with low adherence to the diet, according to the study’s findings. Of the 868 people in the high group, 9 percent had poor thinking skills, compared to 29 percent of the 798 people in the low group, the researchers discovered.
People with high adherence to the APDQS diet were 52 percent less likely to have poor thinking skills than people with low adherence to the diet. Of the 938 people in the high group, 6 percent had poor thinking skills, compared to 32 percent of the 805 people in the low group, the study showed.
The results were adjusted for other factors that could affect cognitive function, such as level of education, smoking, diabetes, and physical activity.
McEvoy noted there were large differences in fruit and vegetable intake between the low and high groups for the diets.
For the Mediterranean diet, the low group had an average of 2.3 servings of fruit per day and 2.8 of vegetables, compared to 4.2 servings of fruit and 4.4 of vegetables for the high group. For the APDQS diet, the low group ate 2.7 servings of fruit and 4.3 of vegetables, compared to 3.7 and 4.4 for the high group, according to the study’s findings.
McEvoy added the study does not show that a heart-healthy diet results in better thinking skills. It only shows an association between the two.
This association was not seen with the DASH diet, the researcher noted.
“One possibility is that DASH does not consider moderate alcohol intake as part of the dietary pattern, whereas the other two diets do,” McEvoy said. “It’s possible that moderate alcohol consumption as part of a healthy diet could be important for brain health in middle age, but further research is needed to confirm these findings.”
“While we don’t yet know the ideal dietary pattern for brain health, changing to a heart-healthy diet could be a relatively easy and effective way to reduce the risk for developing problems with thinking and memory as we age,” she continued.
The study was published in Neurology, the medical journal of the American Academy of Neurology.
Source: American Academy of Neurology