Cancer shows scant regard for healthy diet
April 7, 2010
An international study of almost 500,000 people has confirmed that eating fruit and vegetables does not ward off cancer, debunking a 20-year-old edict by the World Health Organisation.
It also casts a shadow over the federal government's $4.8 million advertising campaign, launched five years ago, to encourage people to eat two pieces of fruit and five serves of vegetables a day.
But cancer experts yesterday urged people not to disregard the advice, saying a high intake of fruit and vegetables was still beneficial against heart disease and that some cancers, such as bowel and breast, were linked to 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,'' the chief executive of the Cancer Council of Australia, Ian Olver, said.
The eight-year study, by researchers in Europe, analysed 478,000 people and found that eating about 400 grams of fruit and vegetables a day offered only modest protection against developing cancer.
Published in the Journal of the National Cancer Institute and undertaken between 1992 and 2000, the study found ''no conclusive evidence'' of a link between cancer and fruit and vegetables despite a review in 1997 by the World Cancer Research Fund that claimed to have found convincing evidence.
But Bruce Armstrong, a professor of public health at the University of Sydney, said the study, which did not focus on any particular cancer, masked the results for some types of the disease that were linked to diet.
''Fruit and vegetables definitely do have a protective effect against some cancers, so we have not been giving people the wrong message,'' he said.
The results also support a 2007 Australian study that found that staying within a healthy weight range was more important in cancer prevention than following nutritional guidelines.