Munching a bowl of blueberries for breakfast can stop you flagging in the afternoon, a new study shows.
Researchers found that a large helping of the fruit - described by some as nature's 'superfood' - boosts concentration and memory up to five hours later.
In tests, volunteers who drank a blueberry smoothie in the morning did much better at mental tasks in the mid afternoon than people who had an alternative drink. British scientists who made the discovery believe the antioxidants in blueberries stimulate the flow of blood and oxygen to the brain - and keep the mind fresh. The finding means people could use blueberries and other fruit rich in anti-oxidants to improve their chances during exams or on long, difficult days at work.
Dr Jeremy Spencer of Reading University, who carried out the study, said: 'After one hour there was little difference in the attention tests. But after five hours people who didn't have the blueberry smoothie saw their performance fall by 15 to 20 per cent.'
Blueberries are bursting with vitamins C and E. Nutritionists say they are one of the richest sources of cancer-fighting antioxidant called flavonoids, which are also found in green tea, wine, grapes and cocoa.
Past studies have shown that flavonoids can protect against degenerative diseases and even help people lose weight.