Healthy eating promises sharp brain
Keeping a healthy diet in midlife protects against cognitive impairment in older age, according to a recent Singapore study.
“[W]e found that five predetermined healthful dietary patterns were inversely associated with the risk of cognitive impairment in the Singapore Chinese population,” said researchers. “These findings suggest that maintaining a healthy dietary pattern is important for the prevention of onset and delay of cognitive impairment.”
Accessing the Singapore Chinese Health Study, researchers identified 16,948 participants (mean age, 53.5±6.2 years; 59.2 percent female) in whom cognitive function was assessed using the Singapore-modified Mini-Mental State Examination (MMSE); five different scales were used to measure diet quality. A total of 2,443 (14.4 percent) participants were identified to have cognitive impairment. [Am J Clin Nutr 2019;doi:10.1093/ajcn/nqz150]
Better diet quality lowered the risk of cognitive impairment. For instance, the risk was significantly lower for participants in the highest vs lowest quartile of the alternate Mediterranean Diet (aMED) score (odds ratio [OR], 0.67, 95 percent CI, 0.59–0.77; p-trend<0.001). Taking aMED scores as a continuous variable yielded a similar effect (OR, 0.84, 0.80–0.88).
The same was true for high scores in the Dietary Approaches to Stop Hypertension (DASH; Q4 vs Q1: OR, 071, 0.62–0.81; p-trend<0.001; continuous: OR, 0.89, 0.84–0.93) and alternative Healthy Eating Index (AHEI; Q4 vs Q1: OR, 0.75, 0.66–0.85; p-trend<0.001; continuous: OR, 89, 0.85–0.94).
Moreover, participants who had high scores in the plant-based diet index (PDI; Q4 vs Q1: OR, 0.82, 0.71–0.94; p-trend<0.001; continuous: OR, 0.93, 0.88–0.97) and healthful PDI (Q4 vs Q1: OR, 0.78, 0.68–0.90; p-trend<0.001; continuous: OR, 0.92, 0.88–0.97) were also significantly less likely to develop cognitive impairment.
Generalized linear models showed that each quartile increase across all five dietary scores was associated with better scores in the MMSE. In contrast, each year increment in age produced a decrease of 0.185 points in MMSE scores.
In absolute terms, the difference in cognitive scores between the highest and lowest aMED score quartiles was the equivalent of a 2.93-year age gap. The corresponding values for DASH, AHEI and PDI and healthful PDI were 2.72, 2.45, 1.76 and 1.86 years, respectively.
“Several explanations have been provided for the protective role of these healthy dietary patterns on cognitive health,” such as the positive effects of a healthy diet on metabolic, inflammatory and microvascular function, researchers explained.
“Future longitudinal studies with repeated measures of diet and cognition and clinical diagnosis of dementia among diverse populations are needed,” said researchers. “This would help identify the critical window for diet intervention to have a major impact on cognition and identify the potential population that would benefit the most.”