Posted by: Bystander PJ5 JUN 2013
Looking for something to read while waiting to see my GP, I picked up an NHS leaflet that offered tips on “better eating”. Unfortunately, several of the tips merely repeat popular beliefs for which there is little real evidence.
Perhaps the biggest fallacy is: “Have at least five portions of fruit or vegetables every day”.
This five-a-day mantra is not based on scientific evidence. It was devised in 1991 as a marketing ploy by a group of about 20 US food companies in association with the US National Cancer Institute. The campaign has been remarkably successful despite a dearth of research findings to back the claim.
The trouble with links between diet and health is that it is difficult to prove a causal relationship. There is certainly evidence that those who eat plenty of fruit and vegetables have a reduced risk of heart disease. But no one has shown that this is directly due to the consumption of these foods.
It may well be that eating oodles of vegetables and fruit is simply one indicator of a generally healthier lifestyle. Fans of such produce may have a low risk of heart disease because they also eat less processed food, are more active and are less likely to be smokers.
And when one examines research into the benefits of fruit and vegetables, it is far from conclusive. One European study looked at the diet and health of more than 300,000 people across eight countries for an average of 8.4 years. It found that those who ate at least eight portions of fresh fruit and vegetables (each of 80g or more) had a 22 per cent lower chance of dying from ischaemic heart disease than those who ate no more than three portions.
But only 1,636 participants actually died from heart disease. That is 0.5 per cent. So it seems that, for 99.5 per cent of us, eating lots of fresh fruit and vegetables is irrelevant, and for 0.5 per cent there is a modest risk reduction. The only clear beneficiaries of the “five-a-day” campaign seem to be the businesses that sell us our vegetables and fruit.