SINGAPORE – Individuals who consume a wide variety and substantial quantity of fruits and vegetables during their midlife are less likely to suffer cognitive impairment in their later years, a study has found.
Researchers discovered that participants who consumed an average of around 520g of fruit and vegetables a day were 23 per cent less likely to be cognitively impaired than those who consume an average of 165g a day.
The study, led by Dr Koh Woon Puay, Professor of Healthy Longevity Translational Research Program at 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 decline, independent of quantity.
Dr Koh, corresponding author of the study, said: “It is not enough to just eat more, increasing the variety in the consumption of fruits and vegetables is also important in improving health.”
The study, which was published in the British Journal of Nutrition in March, is the first known study to examine variety of fruits and vegetables independent of quantity intake.
Researchers used data from the Singapore Chinese Health Study, which collected dietary patterns of more than 63,000 Chinese Singaporeans aged 45 to 74 years between 1993 and 1998.
A total of 14 fruits and 25 vegetables were identified as commonly eaten 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 making up the final study population.
The study observed that participants who consumed an average of 10 types of fruit a month were 22 per cent less likely to be cognitively impaired as compared with those who consumed four types.
Participants who consumed 22 types of vegetables monthly had 13 per cent lower risk as compared with those who consumed an average of 13 types.
Fruits were further categorized according to their glycemic index.
Those with a low glycemic index cause a slower rise in blood sugar as compared with those with a higher index.
Vegetable categories included light green vegetables, dark green vegetables, cruciferous vegetables, yellow vegetables, tomato products and mushrooms.
Research found that consumption of fruits with low glycemic index such as apples and peaches, and vegetables from the mushroom, and light green vegetables categories were associated with lower risk of cognitive decline.
Although the study population comprises only Chinese Singaporeans, Dr Koh said the findings would be applicable across all races.
She said: “The benefit (of lower risk of cognitive decline) is due to biological factors and not exclusive to the Chinese. Nutrients and antioxidants in fruit 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 quantity of fruit and vegetable intake was associated with lower risks of cognitive impairment in later stages of life, added Dr Koh.
Dr Chan Tat Hon, who did not participate in the study, said he hopes the research will convince Singaporeans to make changes in their dietary habits.
The doctor, who teaches patients how to make dietary modifications to reduce risk of chronic diseases, added: “This study is extremely actionable. We can start (reducing the risks of declining cognitive ability) today, immediately.”