Consuming five portions of fruit or vegetables each day is linked to a lower risk of premature death but eating more portions appears to have no further effect, their study concluded.
The findings contradict research earlier this year which claimed eating “seven a day” holds the lowest risk of death.
The latest study, published on thebmj.com, examined the association between fruit and vegetable intake and risk of premature death from all cause cardiovascular and cancer deaths.
Researchers from China and the United States analysed 16 studies involving more than 830,000 people – 56,000 of whom died during the follow-up period.
Higher consumption of fruit and vegetables was significantly associated with a lower risk of death from all causes, particularly from cardiovascular disease.
They found the average risk of death from all causes was reduced by about five per cent for each additional daily serving of fruit and vegetables.
But once a person had consumed five portions, there was no additional benefit. “This analysis provides further evidence that a higher consumption of fruit and vegetables is associated with a lower risk of all-cause mortality, particularly cardiovascular mortality,” the authors said.
“There was a threshold around five servings of fruit and vegetables a day, after which the risk of all cause mortality did not reduce further.”
The findings come after a study by researchers in London claimed increasing intake of fruit and vegetables to seven portions a day could reduce the risk of dying of cancer by as much as a quarter and from heart disease by nearly a third.
Margo Barker, senior lecturer in nutritional epidemiology at Sheffield University, said the findings differed but the link with healthy eating was clear and it remained the case only 30 per cent of people ate five portions a day.
“This shows a reduction in risk of cardiovascular disease from fruit and vegetable intake of up to five portions a day but there’s no harm from eating more,” she said.
Eight-year-old Finn Johnson, of Farsley, Leeds, is one who has no problem eating his five a day – particularly broccoli, which is his favourite – and even helps with tending a small vegetable plot.
His father Tony said: “He certainly loves his fruit and veg. He has been eating it ever since he was a little lad.
He even takes stuff like carrots to school as a snack.”
Victoria Taylor, senior dietitian at the British Heart Foundation, said: “This study is another reminder that fruit and vegetables shouldn’t be an afterthought but an essential part of our meals and snacks.
“Although our five a day message is well established, worryingly 70 per cent of adults are still not meeting this target.
“It may seem like a difficult task, but it doesn’t have to be. Whether it’s banana with cereal for breakfast, salad in your lunchtime sandwich or swapping biscuits for fruit, there are lots of easy ways we can up our fruit and vegetable intake.”