Five-a-day should be two fruits and three vegetables to maximise life expectancy, study suggests
Britons have long been encouraged to get their "five-a-day", with a daily intake of numerous fruits and vegetables being linked to a lower risk of disease and early death.
Exactly what an individual consumes within this target is up to them, with fresh, canned, frozen and dried produce all contributing to a healthy and balanced diet.
After analysing more than 2 million adults worldwide, Harvard scientists reported that our five-a-day should be made up of two fruits and three vegetables for a longer life.
Watch: Simple steps to a healthier life
Read more: Why one bad meal can put us off a dish for life
"While groups like the American Heart Association recommend four to five servings each of fruits and vegetables daily, consumers likely get inconsistent messages about what defines optimal daily intake of fruits and vegetables such as the recommended amount, and which foods to include and avoid," said lead author Dr Dong Wang.
In the UK, NHS guidelines state that 80g of fresh, canned or frozen fruits and vegetables count as one portion of someone's five-a-day. People can also up their quota with 30g of dried fruit.
Juice and smoothies also count up to 150ml a day, with any more raising the risk of tooth damage from the natural sugars released during the crushing process.
Read more: Apples boost brain health, mice study suggests
While it may sound an easy enough target to hit, less than a third (28%) of adults in the UK got their five-a-day in 2018, with the average Briton consuming just 3.7 portions.
To better understand the optimal fruit and vegetable intake, the Harvard scientists analysed the diets of more than 2 million people from numerous studies.
Results, published in the journal Circulation, reveal eating around two servings of fruit and three portions of vegetables a day was associated with the greatest longevity.
"This amount likely offers the most benefit in terms of prevention of major chronic disease and is a relatively achievable intake for the general public," said Dr Wang.
Nevertheless, eating five servings of fruits and vegetables a day – whatever the produce consumed – was linked to a lower risk of premature death.
Hitting the five-a-day target was associated with a 13% lower premature death risk from any cause, compared to managing just two fruit or vegetable servings a day.
The death risk from heart disease, cancer or a respiratory disorder, like chronic obstructive pulmonary disease, went down 12%, 10% and 35%, respectively.
Consuming more than five servings was not associated with additional longevity benefits, however.
Read more: Coffee reduces heart failure risk
The results further suggest not all fruits and vegetables are created equal.
Starchy produce, like peas and corn, as well as fruit juices and potatoes, were not associated with a reduced risk of premature death from any cause.
These benefits were most pronounced among green leafy vegetables, like spinach, lettuce and kale.
A high intake of produce rich in the antioxidant beta carotene and vitamin C – like citrus fruits, berries and carrots – were also shown to cut the participants' premature death risk.
"We found not all fruits and vegetables offer the same degree of benefit, even though current dietary recommendations generally treat all types of fruits and vegetables, including starchy vegetables, fruit juices and potatoes, the same," said Dr Wang.
The research was observational, and therefore does not prove cause and effect.
"The American Heart Association recommends filling at least half your plate with fruits and vegetables at each meal," said Dr Anne Thorndike, chair of the association's nutrition committee.
"This research provides strong evidence for the lifelong benefits of eating fruits and vegetables, and suggests a goal amount to consume daily for ideal health.
"Fruits and vegetables are naturally packaged sources of nutrients that can be included in most meals and snacks, and they are essential for keeping our hearts and bodies healthy."
Watch: What counts as one of your five-a-day?
