Eating a "heart healthy" diet may help preserve our memory and thinking abilities as we age, according to new research reported at the Alzheimer's Association 2009 International Conference on Alzheimer's Disease (ICAD 2009) in Vienna.

"We can't do anything about aging or family history, but research continues to show us that there are lifestyle decisions we all can make to keep our brains healthier, and that also may lower our risk of memory decline as we age," said William Thies, Ph.D., Chief Medical & Scientific Officer at the Alzheimer's Association.

The Dietary Approaches to Stop Hypertension (DASH) diet is often recommended by physicians to people with hypertension or pre-hypertension. The DASH diet eating plan has been proven to lower blood pressure in studies sponsored by the National Institutes of Health. High blood pressure is considered a risk factor for Alzheimer's and dementia.

Heidi Wengreen, RD, Ph.D., Assistant Professor of Nutrition at Utah State University, and colleagues examined associations between how closely people adhered to the DASH diet and risk of cognitive decline and dementia among older participants in the Cache County Study on Memory, Health and Aging.

In 1995, 3,831 study participants 65 years of age or older completed a survey that included a food frequency questionnaire and cognitive assessment. Cognitive function was checked again during four assessments over 11 years using the Modified Mini-Mental State examination (3MS), which is graded on a 100-point scale. A DASH diet adherence score was created based on consumption levels of nine food-group/nutrient components - fruit, vegetables, nut/legumes, whole grains, low-fat dairy, sodium, sweets, non-fish meat, and fish. Participants were ranked by DASH score into five quintiles.

The researchers found that higher DASH scores were associated with higher scores for cognitive functioning at the beginning of the study and over time. Those in the highest quintile scored 1.42 points higher at baseline and 1.81 points higher after 11 years on the 3MS than did those in the lowest quintile of the DASH score (p<0.001).

They also found that four of the nine food-group/nutrient components used to create the DASH score were independently associated with 3MS scores - vegetables, whole grains, low-fat dairy, nut/legumes. The scientists created a diet adherence score based on just these four components that they then tested for association with changes in cognitive abilities on the 3MS. Those in the highest quintile scored 1.72 points higher at baseline and 3.73 points higher after 11 years than did those in the lowest quintile of the four-component score (p<0.001).

"Our results suggest that including whole grains, vegetables, low-fat dairy foods, and nuts in one's diet may offer benefits for cognition in late life," Wengreen said. "However, we need more research before we can confidently say how much of these foods to include in your diet to experience some benefit."