Too much citrus fruit consumption may be associated with increased melanoma risk

http://www.eurekalert.org/pub_releases/2015-06/asoc-cfc063015.php

Public Release: 30-Jun-2015
American Society of Clinical Oncology

ASCO Perspective: Gary Schwartz, MD, ASCO Expert "This study adds to the growing discussion around food and cancer risk. While the findings are intriguing, it's far too soon to recommend any broad changes to grapefruit or orange consumption. Until conclusive data are available, we should continue to be cautious about protecting our skin from sun exposure."

A new analysis of dietary patterns among more than 100,000 Americans suggests that frequent consumption of citrus -- namely whole grapefruit and orange juice -- may be associated with an increased risk of melanoma. Melanoma risk was 36% higher in people who consumed citrus fruit or juice at least 1.6 times daily compared to those who consumed them less than twice per week.

Consumption of grapefruit and oranges was not associated with an increased risk for any other non-skin cancers. This analysis, along with an accompanying editorial, "Dietary Advice for Melanoma: Not Ready for Prime Time," was published online today in the Journal of Clinical Oncology.

The study researchers argue that the apparent link between melanoma and citrus fruit consumption may be due to high levels of substances called furocoumarins found in citrus fruits. Prior research showed that furocoumarins make the skin more sensitive to sunlight, including to melanoma-causing ultraviolet (UV) rays.

"While our findings suggest that people who consume large amounts of whole grapefruit or orange juice may be at increased risk for melanoma, we need much more research before any concrete recommendations can be made," said lead study author Shaowei Wu, PhD, a postdoctoral research fellow at the Department of Dermatology, the Warren Alpert Medical School of Brown University in Providence, Rhode Island. "At this time, we don't advise that people cut back on citrus -- but those who consume a lot of grapefruit and/or orange juice should be particularly careful to avoid prolonged sun exposure."

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