Eating seven or more portions of fruit and vegetables a day gives people a far greater chance of staving off an early death, according to a study suggesting the five a day recommendation should be doubled.
Researchers found that eating seven fruit and veg helpings a day reduced a persons risk of dying of cancer by 25 per cent and of heart disease by 31 per cent. But in a surprising finding, eating tinned and frozen fruit appeared to increase the risk.
Current NHS guidance, which is in turn based on advice from the UN's World Health Organization, states that every person should try to have five different 80g portions of fruit and vegetables a day.
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Examining the eating habits of 65,000 people in England between 2001 and 2013, the researchers from University College London (UCL) found that people who ate seven or more portions daily had a 42 per cent reduced risk of death overall compared with those who managed just one.
Fresh vegetables were found to have the strongest protective effect, followed by salad and then fruit. Overall, vegetables pack more of a protective punch than fruit, the authors said.
The study was published in the Journal of Epidemiology and Community Health. In an accompanying editorial, public health doctors from the University of Liverpool said the findings prompted the question: Is it perhaps now time for the UK to update the five a day message to 10 a day?
The doctors added that as a maximum recommended daily amount of fruit and vegetables could not easily be defined, the Government's current five-a-day guide might provide a false reassurance and risk complacency among people who already ate that amount. They need to aim higher, they said.
We all know that eating fruit and vegetables is healthy, but the size of the effect is staggering, said the study's lead author, Dr Oyinlola Oyebode, of UCLs Department of Epidemiology and Public Health. The clear message here is that the more fruit and vegetables you eat, the less likely you are to die at any age.
The research suggested that vegetables are more effective at warding off an early death than fruit. Two to three daily portions of vegetables resulted in a 16 per cent lower risk of death among those studied, compared with 10 per cent for the equivalent amount of fruit.
In Australia, official health advice encourages people to eat two helpings of fruit and five portions of vegetables a day. The authors said their findings suggested that the two plus five diet was a sensible approach.
The most controversial finding was that tinned and frozen fruit increased a persons risk of death by 17 per cent, which the authors suggested may be down to the high amounts of sugar contained in many brands, cancelling out the positive effect of the fruit itself.
Most canned fruit contains high sugar levels and cheaper varieties are packed in syrup rather than fruit juice, Dr Oyebode said. The negative health impacts of the sugar may well outweigh any benefits.
However, other scientists raised concerns about reading too much into the link because the researchers were not able to rule out other aggravating factors, such as poor access to fresh groceries or pre-existing health conditions.
Dr Gunter Kuhnle, a food scientist from the University of Reading, said: Its possible that eating tinned fruits is an indicator of high sugar intake, but it might also be a marker of poverty or lower socio-economic class. As there is no data, its simply not possible to speculate.