The study recently concluded and conducted by a group of scientists shows that higher diet quality is associated with a reduced risk of cognitive decline. The researchers used the food frequency questionnaire to estimate how “healthy” people’s dietary habits were, awarding higher scores to frequent consumption of foods like vegetables, fruits, nuts, soy proteins and fish.
The research included more than 27,000 men and women age 55 and older, enrolled in 2 international parallel trials of the ONTARGET (Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial) and TRANSCEND (Telmisartan Randomised Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease). The subjects had a history of coronary, cerebral or peripheral artery disease or high-risk diabetes and who were followed until death, stroke, heart attack or hospitalization.
During the 56 months of follow-up, 4,699 cases of cognitive decline occurred. The study observed lower risk of cognitive decline among those in the healthiest dietary quintile of modified Alternative Healthy Eating Index compared with lowest quintile (hazard ratio 0.76, 95% confidence interval 0.66–0.86, Q5 vs Q1). Lower risk of cognitive decline was consistent regardless of baseline cognitive level.
“As our study is observational, we can only say that a healthy diet was associated with a reduced risk of cognitive decline and cannot definitively say there is a causal relationship,” said lead author Andrew Smyth of McMaster University in Hamilton, Ontario, Canada, and the National University of Ireland in Galway.
The top fifth of people with the healthiest diets were about 24 per cent less likely to experience cognitive decline during the study than the bottom fifth with the worst diet scores, the study team reports in Neurology.