A daily serving of 1/4 grapefruit or more could raise a woman's risk of breast cancer by up to 30 percent, a study published in the British Journal of Cancer concludes.
Grapefruit is thought to boost the effects of oestrogen, the female hormone that's been linked to an increased risk of breast cancer, researchers at the University of South Carolina and the University of Hawaii wrote.
Study leaders asked some 50 000 post-menopausal women how often they ate the fruit, and how large the portions were, BBC News reported.
More studies needed
The researchers conceded that more study was needed because the questionnaires did not account for consumption of grapefruit juice, only the fruit itself, the BBC said.
The report cited a nutrition scientist at the British Nutrition Foundation, Dr Joanne Lunn, who agreed that follow-up research was needed.
"This study is simply a piece of the jigsaw that will eventually help us to understand how our diets affect our health," she said. – (HealthDayNews)
Grapefruit works as diet aid