Future studies will be required to determine if quercetin, DHBA and other phytonutrients can enhance learning and cognitive function in humans.
Flavonoids, the abundant phytonutrients found in fruits and vegetables, can modulate molecular signalling pathways that influence cognitive abilities.
Dietary flavonoids are naturally occurring in fruit, vegetables, chocolate, and beverages like red wine and tea.
Although it’s known an apple a day keeps the doctor away, two daily apples might be better to reduce the risk of suffering a heart attack or stroke, experts found in 2019.
When 40 people with slightly high cholesterol ate two large apples a day for eight weeks, it lowered their levels of ‘bad’ cholesterol by almost four per cent.
Two apples a day could help to reduce their risk of a stroke or heart attack, which can be caused by cholesterol hardening the arteries.
‘It seems the old adage of an apple day was nearly right,’ said study author Professor Julie Lovegrove, from the Hugh Sinclair Unit of Human Nutrition at the University of Reading, at the time.
‘We believe the fibre and polyphenols in apples are important, and apples are a popular fruit among all ages, which are easy to eat and make great snack foods.’
How an apple a day also helps keep the pounds away: Plant compounds can reduce amount of energy absorbed from foods
An apple a day not only keeps the doctor at bay – it also helps you shed the pounds, according to researchers.
Fruit and vegetables that contain high levels of flavonoids seem to stop people putting on weight.
Flavonoids are plant compounds found in berries, apples, pears, strawberries and radishes.
They have long been celebrated for their antioxidant effect, which is thought to help prevent cell damage.
But experts also think that the compounds may also help reduce the energy – particularly from sugar – that is absorbed from food.
In 2016, researchers at the University of East Anglia (UEA) and Harvard Medical School found that certain flavonoids were linked to maintaining a healthy weight, and even helped people lose a little.
Eating the flavonoids contained in an 80g (2.8oz) handful of blueberries every day for four years would help people lose about 2lb 10oz.
By comparison, the average woman in the same period would usually put on about 2lb 3oz, and the average man 4lb 6oz.
In the study, published in the British Medical Journal, experts examined data for 124,086 men and women in the U.S. over a 24-year period.
The research focused on three large groups of people – one featuring women with an average age of 36 at the start of the study, another with women aged 48, and the third for men with an average age of 47.
Professor Aedin Cassidy, from the UEA’s Norwich Medical School, said: ‘This is the first large study to examine the associations between consumption of all flavonoids and weight gain in middle-aged and older adults.
‘Most adults gain weight as they age and even small increases in weight can have a substantial impact on risk of high blood pressure, developing heart disease, cancer or diabetes – so strategies to help individuals maintain a healthy weight in middle-age are needed.
‘We found that an increased consumption of most flavonoids was associated with weight maintenance, and even a modest weight loss. The results were found to be consistent across men and women, and different ages.
‘However losing even small amounts of weight, or preventing weight gain, can improve health and these modest effects were seen with a small, readily achievable increase in intake of many of these fruits.
‘Just a single portion of some of these fruits per day would have an important impact on health at a population level.’
Professor Cassidy said the strongest links were found for foods containing anthocyanins, which are found in blueberries, strawberries, cherries, blackberries, grapes, radishes and blackcurrants.
She said: ‘We also found that flavonoid polymers – found in tea and apples – were particularly beneficial, along with flavonols – found in tea and onions.’