An international study of almost 500,000 people has shown eating a diet rich in fruit and vegetables may not lower a person's risk of getting cancer.
The report was published in the Journal of the National Cancer Institute, highly regarded as a source for the latest news on cancer research.
The study examined the diets of 478,000 men and women in 10 western European countries for over eight years, and found those who ate a lot of fruit and vegetables did not have a significantly reduced chance of cancer.
This contradicts the long held view of the World Health Organisation that a diet high in fresh produce could help prevent the disease, the Sydney Morning Herald reported.
The authors said their study pointed to only a weak link between a high intake of fruits and vegetables and a reduced cancer risk.
Health experts warned people not to disregard fruit and vegetables, as a diet rich in them could help prevent heart disease, while some cancer types, like bowel and breast, are linked with obesity.
'We are still not clear why fresh fruits and vegetables would reduce cancer but we do know that some cancers are related to obesity, so regardless of these findings, people should be staying within a normal weight range,' said Ian Olver, chief executive of the Cancer Council of Australia.
The report's findings were questioned by Bruce Armstrong, a professor of public health at the University of Sydney, who said the study did not focus on specific cancer types, and masked the results for some types that were linked to diet.
'Fruit and vegetables definitely do have a protective effect against some cancers. The evidence for bowel and oesophageal cancers remain strong, so we have not been giving people the wrong message,' he said.