Even people who eat five portions of fruit and vegetables a day may be missing out on a key nutrient, researchers have suggested.
Fewer than one in five people get enough flavanols in their diets, but eating plenty of blueberries, plums, blackberries, broad beans and cherries, all washed down with green tea, is an ideal way to boost levels of this nutrient.
Flavanols, found in berries as well as dark chocolate, are a type of antioxidant that can support heart health and boost circulation by reducing inflammation.
Dr Javier Ottaviani, lead author of the study, said: “Flavanols can significantly reduce the risk of dying from cardiovascular disease, but only if you consume enough of them.
“Most people assume that eating plenty of fruit and vegetables covers this, but what this research shows is that the specific choices you make matter far more than the total amount. Including a handful of blackberries, a whole apple or having a cup of green tea alongside your meal could make a real difference to how much of these beneficial compounds you actually consume and absorb from the diet.”
In a study published in the journal Food and Function, researchers tracked the diets of 30,000 people from the US and UK and found most people didn’t consume enough flavanols (500mg) every day.
The largest clinical trial of flavanols by researchers at Harvard found a daily intake of 500mg of flavanols significantly reduced the risk of dying from heart disease, but most people do not consume this amount.
The foods with the highest flavanol content per portion are:
- Plums (500g, roughly one punnet): approximately 450mg of flavanols
- Cranberries (250g, roughly one punnet): approximately 300mg of flavanols
- Blackberries (200g, roughly one punnet): approximately 250mg of flavanols
- Green tea (one 250ml cup): approximately 200mg of flavanols
- Broad beans/fava beans (80g, a small handful): approximately 140mg of flavanols
- Cherries (400g, roughly one punnet): approximately 130mg of flavanols
- Apples with skin (200g, one medium apple): approximately 110mg of flavanols
- Strawberries (200g, roughly one punnet): approximately 90mg of flavanols
- Blueberries (150g, roughly one punnet): approximately 80mg of flavanols
- Pinto beans (40g, two tablespoons dry): approximately 70mg of flavanols
Professor Gunter Kuhnle, of the University of Reading, said: “Five-a-day is the right message, but we may need to think more carefully about which five.
“Different fruits and vegetables offer very different nutritional benefits beyond vitamins and minerals, and as our understanding of these compounds grows, there is a real opportunity to make dietary guidance more specific and more effective.”
The researchers at the University of Reading, Harvard Medical School, and the University of California in Davis have been doing flavanol studies with the chocolate manufacturing giant Mars Inc, which is investigating cocoa flavanol supplements.
Although some small trials have shown flavanols can have a positive effect on blood pressure, there is insufficient evidence for eating more flavanol-rich foods.
Naveed Sattar, professor of cardiometabolic medicine at the University of Glasgow, said people should be encouraged to eat more fruit and vegetables, but not just for their antioxidant qualities.
“The primary rationale for this remains increasing fibre intake, which has a far more robust and consistent evidence base. At present, there is insufficient justification for focusing specifically on flavonoid-rich foods per se,” he told The Independent.
