Colour and Brain Health
You may well have heard about the recommendation to eat colourful foods – the rainbow diet as it is called. This is generally regarded as being good for the immune system. A new study has found that people who eat a diet that includes at least half a serving per day of foods high in flavonoids may have a 20% lower risk of cognitive decline. Flavonoids are antioxidants found in plant foods especially fruits, vegetables, herbs and spices.
The research found that two specific flavanoids called flavones and anthocyanins appear to have the most protective effects. Flavones are found in some spices and yellow and orange fruits and vegetables. Anthocyanins are found in blueberries, blackberries and cherries.
The Research Findings
The study looked at the diets of over 70 thousand men and women over a 20 year time span. The intake of different types of flavonoids was calculated by multiplying the flavonoid content of each food by its frequency. The participants evaluated their own cognitive abilities twice during the study, answering questions such as, “Do you have more trouble than usual remembering recent events?” and “Do you have more trouble than usual remembering a short list of items?” This type of assessment may help identify early memory problems when people’s memory has worsened enough for them to notice, but not necessarily enough to be detected on a formal screening test. After adjusting for factors like age and calorie intake, people who consumed more flavonoids in their diets reported lower risk of cognitive decline (1).
A colourful diet rich in flavonoids, specifically flavones and anthocyanins, seems to be a good bet for promoting long-term brain health. The good news is that it’s never too late to start. The protective effects of eating the colourful foods were there whether people were consuming the flavonoids 20 years ago, or if they had started eating them more recently.
Different coloured foods contain different antioxidants. Eating a wide range of colours means you get a broad range of benefits. Try to eat foods from each of these colour groups at least every week, if not every day:
Black/Blue/Purple – blueberries, black berries, blackcurrants, red cabbage, beetroot, aubergines, black olives, aduki beans, black turtle beans.
Red – strawberries, raspberries, red currants, tomatoes, watermelon, red grapefruit, red onions, paprika, kidney beans, red peppers.
Orange – carrots, winter squash and pumpkins, sweet potatoes, apricots, peaches, nectarines, oranges, satsumas, papaya, mangos.
Yellow – melons, lemons, grapefruit, plums, yellow courgettes, yellow peppers, turmeric.
Green – lettuce, rocket, pak choi, spinach, chard, kale, broccoli, cabbage, green beans, peas, celery, green olives, herbs.
1. Tian-Shin Yeh et al. Long-term Dietary Flavonoid Intake and Subjective Cognitive Decline in US Men and Women. Neurology, 2021;