SINGAPORE – People who eat a wide variety and substantial amount of fruits and vegetables during middle age are less likely to experience cognitive decline in their later years, according to a study.
The researchers found that participants who ate an average of around 520g of fruit and vegetables a day were 23% less likely to experience cognitive decline than those who ate an average of 165g a day.
The study, led by Dr. Koh Woon Puay, a professor in the Healthy Longevity Translational Research Program at the National University of Singapore Yong Loo Lin School of Medicine, also found that increasing the variety of fruits and vegetables consumed also reduced the risk of cognitive impairment, regardless of amount.
Dr. Koh, corresponding author of the study, said: “It is not enough to eat more, increasing the variety in the consumption of fruits and vegetables is also important for improving health.”
The study, which was published in the British Journal of Nutrition in March, is the first known study to examine the variety of fruits and vegetables regardless of the amount of intake.
The researchers used data from the Singapore Chinese Health Study, which collected dietary patterns from more than 63,000 Chinese Singaporeans aged 45 to 74 between 1993 and 1998.
A total of 14 fruits and 25 vegetables were identified as commonly consumed foods and included in the study.
Twenty years after the study, a follow-up interview was conducted to measure their cognitive function, with 16,737 participants who made up the final study population.
The study found that participants who ate an average of 10 types of fruit per month were 22 percent less likely to have cognitive problems compared to those who ate four types.
Participants who ate 22 types of vegetables monthly had a 13 percent lower risk compared to those who ate an average of 13 types.
Fruits were further ranked according to their glycemic index.
Those with a low glycemic index cause a slower rise in blood sugar compared to those with a higher index.
Vegetable categories included light green vegetables, dark green vegetables, cruciferous vegetables, yellow vegetables, tomato products, and mushrooms.
The research found that consumption of fruits with a low glycemic index, such as apples and peaches, and the vegetable categories of mushrooms and light green vegetables were associated with a lower risk of cognitive decline.
Although the study population comprises only Chinese Singaporeans, Dr. Koh said the findings would be applicable across races.
She said: “The benefit (of lower risk of cognitive decline) is due to biological factors and is not unique to the Chinese. The nutrients and antioxidants in fruits and vegetables are good for protecting brain function.”
The findings were consistent with other studies conducted in Europe, the United States and Japan, which similarly concluded that higher fruit and vegetable intake was associated with lower risks of cognitive decline later in life, added Dr. Koh.
Dr Chan Tat Hon, who was not involved in the study, said he hopes the research will convince Singaporeans to make changes to their eating habits.
The doctor, who teaches patients how to make dietary modifications to reduce the risk of chronic disease, added: “This study is extremely actionable. We can start (reducing the risks of decreased cognitive ability) today, immediately.”
