Researchers discovered that those who regularly consumed orange juice or whole grapefruit had a higher risk of developing melanoma, the deadly form of skin cancer compared to people who avoided those foods.
Dietary patterns of more than 100,000 Americans showed an unexpected link between high consumption of citrus - specifically whole grapefruit and orange juice and risk of melanoma, the most dangerous form of skin cancer.
Researchers found that 1,840 of the study participants developed melanoma. Those who had a serving of citrus fruit or juice daily had a 36% higher risk of the cancer as compared with those who consume it less than two times a week.
The link may be due to high levels of furocoumarins found in citrus fruit. Plants as a defence mechanism and are photoactive produce these substances, meaning that ultraviolet radiation increases their toxicity. They have been known to cause skin to be more sensitive to sunlight.
Shaowei Wu, the lead study author and a postdoctoral research fellow at the Warren Alpert Medical School at Brown University, said, "those who consume a lot of grapefruit and/or orange juice should be particularly careful to avoid prolonged sun exposure."
The American Society of Clinical Oncology called the findings "intriguing" but said that it's far too soon for any changes to dietary recommendations about grapefruit and oranges.