Broccoli and tomato cancer impact "unclear"
The effect of broccoli and tomato on health remains "unclear", Cancer Research UK has said, following research linking the vegetables to a reduced risk of prostate cancer.
The University of Illinois trials found that rats fed a diet including ten per cent tomato and ten per cent broccoli as powder developed smaller prostate tumours than other rats.
"While this work supports previous suggestions that both broccoli and tomatoes may contain chemicals with anticancer properties, their effects in humans are still unclear." said Dr Julie Sharp of Cancer Research UK.
"This research has been done in the laboratory but studies of these specific vegetables in large numbers of people have produced conflicting results.
"However, studies have shown that a healthy balanced diet, including plenty of fresh vegetables and fruit,can help to reduce the risk of cancer ."
Some studies have supported the idea that lycopene, the substance which makes tomatoes red, and sulphur compounds found in broccoli, can have an anti-cancer effect.
Prostate cancer is the most common form of the disease among British men, with around 32,000 new cases diagnosed every year.
The study is published in the journal Cancer Research.