Plant-rich diets reduce cognitive impairment risk in old age

The team looked at the diet patterns of the nearly 17,000 middle-aged participants of the Singapore Chinese Health Study over a period of 20 years.

Researchers from the NUS Saw Swee Hock School of Public Health (SSHSPH), NUS Yong Loo Lin School of Medicine and Duke-NUS Medical School (Duke-NUS) are among the team of nine who have found, in the first local study, that keeping to a healthy diet comprising high intake of plant foods and low intake of animal foods in midlife could be associated with a reduced risk of cognitive impairment in old age.

The team looked at the diet patterns of the nearly 17,000 middle-aged participants of the Singapore Chinese Health Study over a period of 20 years. The participants were scored on how similar their diet patterns were to five high quality diets, the alternative Mediterranean diet; the Alternate Healthy Eating Index 2010; the Dietary Approaches to Stop Hypertension diet; the plant-based diet index; and the healthful plant-based diet index.

Rich in plant-based foods, including whole grains, vegetables, fruits, nuts and legumes, and low in red meat and sugar-sweetened beverages, these dietary patterns have been shown to reduce the risk of cancer, diabetes and cardiovascular diseases.

The results, recently reported in the American Journal of Clinical Nutrition, revealed that participants with the most similarity to these dietary patterns had a significant reduction in risk of cognitive impairment, of 18 per cent to 33 per cent, compared with those with the least similarity.

Singaporeans currently lead the world in life expectancy, with life spans averaging 85 years. This, along with an ageing population, has increased the need to identify and take measures to prevent the development of common conditions associated with old age such as cognitive impairment and dementia.

Describing the impact of the findings, Duke-NUS and SSHSPH Professor Koh Woon Puay, Principal Investigator of the Singapore Chinese Health Study, said, “Our study suggests that maintaining a healthy dietary pattern is important for the prevention of onset and delay of cognitive impairment. Such a pattern is not about the restriction of a single food item but the composition of an overall pattern that recommends cutting back on red meats, especially if they are processed, and including lots of plant-based foods — vegetables, fruit, nuts, beans, whole grains — and fish.”

The Health Promotion Board, Singapore (HPB) recommends eating across all food groups for a balanced and varied diet. “A simple guide is to fill half our plate with fruit and vegetables, a quarter with wholegrains such as brown rice and wholemeal bread, and the last quarter with protein foods such as bean products, seafood and meat,” advised HPB Policy, Research and Surveillance Division Group Director Dr Annie Ling.