Eating a lot of fruit and vegetables has only "a very modest" effect on protecting against cancer, according to a study. Researchers suggest that the "five portions a day" health mantra has strong validity only when it comes to preventing the disease in heavy drinkers. Even then the benefits may apply only to cancers caused by alcohol and smoking, such as those in the gut, throat and mouth.
The verdict is based on a study of almost 500,000 people in 10 European countries and suggests that even the small overall association of fruit and vegetable consumption with prevention of cancer may be linked to other factors. Fruit and vegetable intake was compared with cancer data covering nine years up to 2000 for the research published in the Journal of the National Cancer Institute.
Researchers adjusted the results for other factors likely to influence the results, such as smoking, alcohol intake, obesity, consumption of meat and processed meat, exercise and whether women had taken the contraceptive pill or hormone replacement therapy. The results showed that eating an extra 200g of fruit and vegetables a day reduced the overall risk of cancer by 3%. The link between eating a large amount of vegetables and reduced cancer risk applied only to women.
The study, led by Paolo Boffetta from the Tisch Cancer Institute at Mount Sinai School of Medicine in New York, suggested a "weak" association between high fruit and vegetable intake and reduced cancer risk.