Up to 7.8 million deaths per year could be prevented if people were to eat 10 portions of fresh fruit and vegetables each day as opposed to the familiar “five-a-day” mantra that has been pushed by health experts in Britain for more than a decade.
And some of the best fruit and vegetables associated with preventing heart disease, stroke, cardiovascular disease and early death include apples, pears, citrus, salads and green leafy vegetables like spinach, lettuce and chicory, as well as cruciferous vegetables such as broccoli, cabbage and cauliflower.
Imperial College London scientists analysed 95 studies on fruit and vegetables to come up with the findings which show eating above five-a-day leads to major health benefits including reducing the risk of heart disease, stroke, cancer and premature death.
Although the five-a-day message does impact on health, increasing the amount of fresh produce has a significant impact. According to the research, the greatest benefit came from eating 800g (1.7lbs) a day which equates to approximately ten portions.
The meta-analysis of all available research in global population amounted to two million people and investigated 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.
Eating 10 portions a day is 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 dying prematurely. This risk was calculated in comparison to not eating any fruit and vegetables.
“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, ten a day is even better,” said Dr Dagfinn Aune, lead author of the research from the School of Public Health at Imperial.
Published in the International Journal of Epidemiology, the research estimate 7.8 million premature deaths worldwide could be potentially prevented every year if people ate at the 10 portion level. The study also showed that even 200g daily consumption shows a 16% link to reduced risk of heart disease, an 18 per cent reduced risk of stroke, and a 13 per cent reduced risk of cardiovascular disease.
The current UK guidelines are to eat at least five portions or 400g (14.1oz) per day, however fewer than one in three UK adults are thought to meet this target.
The scientific team couldn’t examine the impact of more than 800g a day because this was the high end of the range across studies.
Dr Aune added that several potential mechanisms could explain why fruit and vegetables have such profound health benefits:
“Fruit and vegetables have been shown to reduce cholesterol levels, blood pressure, and to boost the health of our blood vessels and immune system. 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.
“Most likely it is the whole package of beneficial nutrients you obtain by eating fruits and vegetables that is crucial is health. 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).”
During the analysis the team took into account other factors like weight, smoking, physical activity and overall diet.
“We need further research into the effects of specific types of fruits and vegetables and preparation methods of fruit and vegetables. We also need more research on the relationship between fruit and vegetable intake with causes of death other than cancer and cardiovascular disease. However, 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,” adds Dr Aune.