According to a new study, eating five servings of fruit and vegetables a day does little to reduce a person's risk of cancer. The findings go against the long-standing advice that regular helpings of fruit and vegetables will lower cancer risk.
In 1990, the World Health Organization recommended eating five servings of fruit and vegetables a day to reduce cancers, and this is heavily promoted in the US, UK and Australia.
However, since then studies had failed to confirm of any specific health benefit in adhering to the five a day advice, according to authors of the study published by Oxford University Press, in the Journal of the National Cancer Institute.
The study examined the risks of 142,605 men and 335,873 women. They were all recruited between 1992 and 2000 for the Epic study, European Prospective Investigation into Cancer and Nutrition.
The details of the eating habits of the recruits from23 centres in Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden and the UK were recorded.
Over the eight years, more than 30,000 participants eventually developed cancer. Based on analysis, the authors found there was only a very small association between high intake of fruit and vegetables and a reduced cancer risk.
For those keen on vegetables, the benefits recorded were modest, with gain only seen in women, not men.
Analysis on heavy drinkers showed that those who ate plenty of fruit and vegetables also gain a small benefit. The reduction of cancer risk was only seen in tumours associated with smoking and alcohol consumption.
The authors of the study, led by Dr Paolo Boffetta of the Mount Sinai school of Medicine in New Your and colleagues warn against any assumption that a specific diet could lead to cancer-risk reduction, despite the long-standing wisdom that says so.
The high fruit and vegetables intake may actually reflect a tendency to other positive lifestyle choices, the authors theorize.
In the population, a higher intake of fruits and vegetables was also associated with other lifestyles variables, such as lower intake of alcohol, never smoking, short duration of tobacco smoking and higher level of physical activity, which may have contributed to a lower cancer risk.