Four studies from the Alzheimer's Association conference in Vienna shed more light on the links between diet and exercise, and Alzheimer's disease. The first looked at the effects of a diet designed to help people with high blood pressure, which is a risk factor for Alzheimer's. The study, carried out by researchers at Utah State University, looked into the links between how closely people followed the DASH (Dietary Approaches to Stop Hypertension) diet and their risk of cognitive decline and dementia. Over the course of an 11-year study of 3,831 people they found that those who stuck most closely to the DASH diet had better cognition. Four types of food - vegetables, whole grains, low-fat dairy and nuts/legumes - were particularly associated with higher scores for cognition over the course of the study
A second study by researchers at the University of California, San Francisco looked at the links between physical activity and cognition in 3,075 people aged between 70-79. It found that those participants who were more physically active had better cognition and that people who were sedentary at the start of the 7-year study but who then took more exercise showed an improvement in cognitive function.
A third study looked into the links between activity levels and cognition in women who had just been through the menopause. Researchers from the University of Toronto studied 90 women between the ages of 50 and 63. After adjusting for factors such as age, education, cigarette smoking and alcohol consumption they found that while moderate exercise was associated with improved cognitive function long-term strenuous exercise was associated with a decline in cognitive function. This could be because strenuous exercise reduces levels of ovarian hormones; something associated with a decreased risk of breast cancer but an increased risk of cognitive impairment.
Finally researchers at Howard University in Washington, D.C. looked at how genes affect the links between exercise and cognition. They studied 1,799 people over 60. They found that after adjusting for age, ethnicity, chronic illness, body fat and education exercise still had a significant association with improved cognitive function. However, among people with the APOE-E4 gene - which increases the risk of Alzheimer's - there was no statistically-significant association between exercise and Alzheimer's risk.