The truth behind the 10-a-day claim

A new study led by Imperial College London suggests that eating 10 portions of fruit and veg per day can cut the risk of heart disease, stroke, cardiovascular disease and cancer. Overall, scoffing this mound of vegetation appeared to cut the risk of ‘dying prematurely’ by 31 per cent.

Understandably, many people reacted with a degree of horror. One portion of fruit and veg, according to official guidelines, is 80 grams. So 10 portions is a bowel-challenging 800 grams. Such an intake is fine if you’re a chimpanzee or a vegan, but for the rest of us – who already struggle to eat the regulation five-a-day – it’s a complete non-starter.

However, a little nuance is required. The study is comparing health outcomes with people who eat no fruit and veg at all. And the kind of people prepared to eat enormous quantities of fruit and veg are undoubtedly very different in lots of other ways from those who are complete veg-dodgers. We shouldn’t assume that all the benefits identified by the study are simply down to diet. There could be other differences not controlled for in the study that could explain at least some of the difference.

There are nutrients in fruit and veg that are important – but we don’t need huge amounts of them. That’s reflected in the study’s findings: eating 200 grams of fruit and veg per day – or 2.5 portions – offers half or more of the benefits of eating 10 portions. For example, the 10-portion eater could expect a cut in heart disease risk of 24 per cent, but someone eating a quarter of that amount would still get a 16 per cent reduction, according to the study.

So the study’s findings are not nearly as gobsmacking as that ’10-a-day’ claim appears. Eat some fruit and veg every day. Ideally, it would appear, choose ‘cruciferous’ veg like broccoli, cabbage and cauliflower, which seem to have the biggest effect on health. In short, eat some greens. Whether eating 800 grams per day rather than 200 grams a day is worth the effort, or the flatulence, is up to you.

Rob Lyons is a spiked columnist.