Five portions of fruit and veg a day is good for you, but 10 is much better and could prevent up to 7.8 million premature deaths worldwide every year, say scientists.
The findings of the study led by Imperial College London may dismay the two in three adults who struggle to manage three or four portions – perhaps some tomatoes in a sandwich at lunchtime, an apple and a few spoonfuls of peas at dinner.
All of that is good because a daily intake of even 200g, or two and a half standard 80g portions, is associated with a 16% reduced risk of heart disease, an 18% reduced risk of stroke, a 13% reduced risk of cardiovascular disease, 4% reduced risk of cancer and a 15% reduction in the risk of premature death.
But the study suggests we should be piling up platefuls of vegetables and raiding the fruit bowl every day if we want the best chance of avoiding chronic diseases or an early death.
“We wanted to investigate how much fruit and vegetables you need to eat to gain the maximum protection against disease, and premature death. Our results suggest that although five portions of fruit and vegetables is good, 10 a day is even better,” said Dr Dagfinn Aune, lead author of the research from the School of Public Health at Imperial.
Eating up to 800g of fruit and vegetables – equivalent to 10 portions and double the recommended amount in the UK – was associated with a 24% reduced risk of heart disease, a 33% reduced risk of stroke, a 28% reduced risk of cardiovascular disease, a 13% reduced risk of total cancer, and a 31% reduction in premature deaths.
And not all fruit and veg are created equal. Apples and pears, citrus fruits, salads and green leafy vegetables such as spinach, lettuce and chicory, and cruciferous vegetables such as broccoli, cabbage and cauliflower were found to be best at preventing heart disease and stroke.
To reduce the risk of cancer, however, the menu should include green vegetables, such as green beans; yellow and orange vegetables such as peppers and carrots; and cruciferous vegetables.
The researchers did not find any difference between the protective effects of cooked and raw fruit and vegetables.
“Fruit and vegetables have been shown to reduce cholesterol levels, blood pressure, and to boost the health of our blood vessels and immune system,” said Aune. “This may be due to the complex network of nutrients they hold. For instance they contain many antioxidants, which may reduce DNA damage, and lead to a reduction in cancer risk.”
Compounds called glucosinolates in cruciferous vegetables, such as broccoli, activate enzymes that may help prevent cancer. Fruit and vegetables may also have a beneficial effect on the naturally occurring bacteria in our gut, he said.
And it will not be possible to bottle the effects of fruit and vegetables or put them in a pill, he said. Forget the supplements. “Most likely it is the whole package of beneficial nutrients you obtain by eating fruits and vegetables that is crucial to health,” he said. “This is why it is important to eat whole plant foods to get the benefit, instead of taking antioxidant or vitamin supplements (which have not been shown to reduce disease risk).”
The analysis in the International Journal of Epidemiology pooled the results from 95 different studies involving a total of approximately 2 million people. They assessed up to 43,000 cases of heart disease, 47,000 cases of stroke, 81,000 cases of cardiovascular disease, 112,000 cancer cases and 94,000 deaths.
Aune said more research was needed, but “it is clear from this work that a high intake of fruit and vegetables hold tremendous health benefits, and we should try to increase their intake in our diet”.
Sarah Toule, from the World Cancer Research Fund, said: “This interesting research shows just how incredibly important vegetables and fruit are as part of a healthy diet. In fact, they’re essential for maintaining a healthy weight, which our own evidence has shown reduces the risk of 11 common cancers.
“People should aim to eat at least five portions of vegetables and fruit a day but the more the better. If people find this hard, why not start by adding an extra portion of fruit or veg a day to your lunch or try swapping one of your naughty snacks for a piece of fruit?”
