Fruit and vegetables have "little protective effect" against cancer
Researchers have concluded that consuming fruit and vegetables to prevent cancer only has a "modest" effect.
The team analysed data from 500,000 participants and found that eating five portions of fruit and vegetables each day had little effect.
They also said that eating higher or lesser amounts had minimal impact.
Twenty-three centres in 10 European countries contributed to the study which was part of the European Prospective Investigation into Cancer and Nutrition (EPIC).
Although there is evidence of a "small" protective effect of fruit and vegetables, the chance a reduced risk could be caused by something else cannot be ruled out, the researchers said.
In the UK, centres at Cambridge and Oxford were included in the study, which looked at cancer risk between 1992 and 2000.
People's daily consumption of fruit and vegetables was analysed and matched against data on the number of cancers.
Researchers adjusted the results for other factors likely to influence the results, such as smoking, alcohol intake, obesity, meat and processed meat intake, exercise and factors specific to women, such as if they had ever taken the Pill or hormone replacement therapy (HRT).
The latest research, led by Paolo Boffetta from the Tisch Cancer Institute at Mount Sinai School of Medicine in New York, was published in the Journal of the National Cancer Institute.