Following DASH Diet Improves Brain Activity in Overweight Adults

A diet designed to help lower blood pressure may also boost brainpower.

A new study shows the DASH diet in combination with regular exercise improved mental activity by 30% in overweight adults compared with those who didn't diet or exercise. The DASH diet was developed by the Dietary Approaches to Stop Hypertension study and emphasizes low-fat dairy products and low-cholesterol foods as well as carbohydrates and fruits and vegetables.

Researchers say high blood pressure affects about 50% of adults aged 60 and older and increases the risk of Alzheimer's disease and other forms of mental decline like dementia.

Lifestyle modifications, such as diet and exercise, have been shown to lower blood pressure and improve brain activity, but they say this is the first study to look at the combined effects of diet and exercise on brainpower in overweight people with high blood pressure.

"Modifying lifestyles to achieve a healthy body weight, getting regular exercise, and eating properly not only have physical health benefits, but mental health benefits," researcher James Blumenthal, PhD, professor of psychology and neuroscience at Duke University Medical Center in Durham, N.C., says in a news release. "This study has significant implications for slowing down or even reversing age-related cognitive deficits, which may even have greater impact among people vulnerable to develop dementia or Alzheimer's disease."

Diet for the Brain and Body

In the study, published in Hypertension: Journal of the American Heart Association, researchers divided 124 overweight men and women into three groups. One group followed the DASH diet in combination with an aerobic exercise program (30 minutes of exercise, three times a week), another followed the DASH diet alone, and the third did not diet or exercise for four months.

The participants completed a series of tests to assess their brainpower and mental skills, including manipulation of ideas and concepts and planning, at the beginning and end of the study.

The results showed that people who followed the DASH diet in combination with aerobic exercise experienced a 30% improvement in brain function as well as lower blood pressure, improved their cardiovascular fitness, and lost an average of 19 pounds by the end of the study. On average, they lowered their systolic blood pressure (the top number in a blood pressure reading) by 16 points and diastolic blood pressure (bottom number) by 10 points.