Food for thought: Should we be aiming for five a day?

We’re all encouraged to eat a diet packed full of fresh fruit and vegetables, but what’s the evidence that this is good for us? By Jon Turney.

Twenty years ago, the World Health Organization proposed the "five-a-day" guideline for fruit and vegetables. No single study makes a watertight case for this. That would need the rigid control of diets for masses of people and decades of follow-up. But there is much evidence that people who eat more vegetables and - especially - fruit have healthier lives than those who do not.

The EPIC (European Prospective Investigation into Cancer and Nutrition) study is following 500 000 people across ten European countries, for at least ten years, to explore different risk factors for cancers. Results from EPIC indicate that fruit and vegetable intake helps reduce certain types of cancer, although the effect is not as large as researchers anticipated. The results suggest that if everyone ate two more portions of fruit and vegetables a day, around 2.5 per cent of cancers could be avoided.

The protective effect may be higher for smokers and people who drink alcohol. There is also evidence that diets high in fruit and vegetables help reduce heart disease, although that could be because such diets include less fat, salt and sugar.

Read more mythbusting around food online and on p12-13 of 'Big Picture: Food and Diet' magazine. You can order a copy or download a PDF.

Image: A bunch of tomatoes. Tomatoes are commonly referred to as a salad vegetable but are actually fruits. Credit: Wellcome Library, London.

This article is part of the online content for ‘Big Picture: Food and Diet’.