Dairy intake and cognitive health in middle-aged South Australians.

BACKGROUND Consumption of low fat dairy foods may decrease the risk of obesity, type 2 diabetes, hypertension, and all cardiovascular risk factors linked with increased probability of cognitive impairment. AIM To examine associations between dairy intake and self-reported cognitive function and psychological well-being, and to test the novel hypothesis that dairy consumption may benefit cognitive health via its positive effects on cardiometabolic health. METHODS Retrospective cross-sectional analyses were undertaken on data from food frequency questionnaires and self-reported health of 432 men and 751 women, aged 39 to 65 years. Health measures included cardiometabolic health indicators, cognitive and memory functioning, mental health, anxiety, stress, depression and self-esteem; assessed by standardised questionnaires. RESULTS Regression analyses, adjusted for total energy intake and other health confounders, showed that consumption of low fat yogurt was associated with increased quality of memory recall (p=0.029) and greater social functioning (p=0.045) in men. Consumption of low fat cheese was associated with greater social functioning (p=0.021) and decreased stress (p=0.042) in women. Intakes of whole fat dairy products, including ice-cream and cream, were associated with increased depression, anxiety, stress, cognitive failures, poorer memory functioning and general health (all p<0.05). There was no association between cardiometabolic health indicators and dairy consumption. CONCLUSIONS Low fat dairy may have beneficial effects on social functioning, stress and memory, while whole fat dairy may be associated with poorer psychological well-being. Dietary intervention trials are needed to establish whether there is a direct effect of dairy consumption on cognitive and psychological health.