Eating five portions of fruit and veggies every day is known to lessen the chance of heart attack, stroke, cancer and early death. But ten portions daily provides the greatest benefit, based on new research, led by scientists from Imperial College London, which analysed 95 studies on vegetable and fruit intake.
The study, which was a meta-analysis of available research in populations worldwide, included up to 2 million people, and assessed up to 43,000 installments of cardiovascular disease, 47,000 installments of stroke, 81,000 installments of coronary disease, 112,000 cancer cases and 94,000 deaths.
In the study, which is published within the International Journal of Epidemiology, the team estimate approximately 7.8 million premature deaths worldwide might be potentially prevented every year if people ate 10 portions, or 800 g, of fruit and vegetables a day.
The team also analysed which types of fruit and veggies provided the best protection against disease.
Our results suggest that although five servings of fruit and vegetables is nice, ten each day is even better.
Dr Dagfinn Aune, lead author of the research in the School of Public Health at Imperial explained: “We wanted to investigate just how much fruit and veggies you have to eat to achieve the utmost protection against disease, and premature death. Our results suggest that although five servings of fruit and vegetables is nice, ten a day is even better.”
The results revealed that even a daily consumption of 200g was of a 16 percent reduced chance of cardiovascular disease, an 18 percent reduced chance of stroke, and a 13 per cent reduced risk of coronary disease.
This amount, which is equal to 2 . 5 portions, seemed to be related to 4 percent reduced risk in cancer risk, and 15 per cent decrease in the risk of premature death.
Further benefits were observed with higher intakes. Eating up to 800g fruit and vegetables each day – or 10 portions – was associated with a 24 percent reduced risk of cardiovascular disease, a 33 per cent reduced risk of stroke, a 28 percent reduced risk of cardiovascular disease, a 13 per cent reduced risk of total cancer, along with a 31 percent decrease in dying prematurely. This risk was calculated compared to refusing to eat any fruit and vegetables.
The current UK guidelines will be to eat at least five portions or 400g per day. However fewer than one out of three UK adults are believed to meet this target.
The team were not able to research intakes greater than 800 g each day, as this was our prime end of the range across studies.
An 80g part of fruit and veggies equals approximately one small banana, apple, pear or large mandarin. Three heaped tablespoons cooked vegetables such as spinach, peas, broccoli or cauliflower count like a portion.
The researchers also examined the types of fruit and vegetables that could prevent specific diseases.
The current UK guidelines will be to eat at least five portions or 400g per day
They found the next vegetables and fruit may help prevent cardiovascular disease, stroke, cardiovascular disease, and early death: apples and pears, citrus fruits, salads and green leafy vegetables for example spinach, lettuce and chicory, and cruciferous vegetables for example broccoli, cabbage and cauliflower. Additionally they found the next may reduce cancer risk: green vegetables, for example spinach or peas, yellow vegetables, for example peppers and carrots, and cruciferous vegetables.
Similar associations were observed for raw and cooked vegetables in relation to early death, however, additional studies are needed on specific types of fruits and vegetables and preparation methods. The team the quantity of studies was more limited of these analyses, and also the possibility that other specific fruits and vegetables may also reduce risk cannot be excluded.
Dr Aune said that several potential mechanisms could explain why fruit and veggies have such profound health benefits: “Fruit and vegetables have shown to reduce cholesterol levels, blood pressure level, and also to boost the health in our arteries and defense mechanisms. This can be because of the complex network of nutrients they hold. For example they contain many antioxidants, which might reduce DNA damage, and lead to a decrease in cancer risk.”
He added that compounds called glucosinolates in cruciferous vegetables, for example broccoli, activate enzymes that may help prevent cancer. Furthermore fruit and veggies could also possess a beneficial effect on the naturally-occurring bacteria within our gut.
The vast array of beneficial compounds can't be easily replicated inside a pill, he said: “Probably it's the whole package of beneficial nutrients you get when you eat fruits and vegetables that's crucial is health. This is why it is important to eat whole plant foods to get the benefit, rather than taking antioxidant or nutritional vitamin supplements (which have not been proven to reduce disease risk).”
In the analysis, the team took into consideration additional factors, such as a person’s weight, smoking, exercise levels, and overall diet, but still discovered that fruit and vegetables were beneficial.
Dr Aune added: “We want further research in to the effects of specific kinds of vegetables and fruit and preparation ways of fruit and vegetables. We need more research around the relationship between vegetable and fruit intake with reasons for death other than cancer and coronary disease. However, it's clear from this work that a high consumption of fruit and vegetables hold tremendous health advantages, and that we need to improve their intake in our diet.”