Consumption of orange juice and grapefruit are associated with an increased melanoma risk, says a study in the Journal of Clinical Oncology.

Nearly 100,000 white participants completed questionnaires about their consumption of citrus fruits and juices and were followed for roughly 25 years. Participants who reported consuming at least 1.6 servings of citrus daily had a 36% increased risk for melanoma, compared with those who ate less than two servings a week. In analyses by citrus type, the findings were significant only for orange juice (increased risk seen with 5-6 servings/week vs. <1/week) and grapefruit (increased risk with <1/week vs. never).

The authors speculate that the association could be due to the psoralen found in citrus fruits. Animal studies have found that psoralen has photocarcinogenic properties.