Research suggests that eating grapefruit may increase the risk of breast cancer in older women by one-third.
The Daily Mail reports that the study was conducted by researchers from the University of Southern California and the University of Hawaii, and the related paper was published in the British Journal of Cancer.
The researchers analyzed data from 50,000 postmenopausal women from five racial groups, including 1,657 breast cancer patients. They found that grapefruit raises estrogen levels in the blood. "It is a well-established fact that there is an association between estrogen and the risk of breast cancer, therefore, frequent consumption of grapefruit may increase the risk of breast cancer in women." Overall, older women who eat a quarter or more of a grapefruit daily have a 30% increased risk of developing breast cancer. [China Food]
The researchers said: "This is the first study report on a common food potentially increasing the risk of breast cancer in postmenopausal women."
The Daily Mail reports that among all women with cancer, breast cancer cases account for more than a quarter. In the UK, more than 40,000 women are diagnosed with breast cancer each year, and about 12,500 die from it.