Researchers at Brown and Harvard Universities have found a link between orange juice and melanoma. By conducting a study of over 100,000 people, the researchers found that those consuming one and a half servings of citrus a day were 36 percent more likely to develop the skin cancer than those consuming two servings a week. The study was reported on the website GrubStreet, a site devoted to all things food. A serving was defined as six ounces of orange juice, one orange or half a grapefruit.
The conclusion of the scientist is a group of substances called furocoumarin as the likely culprit. All citrus fruits contain this group of chemicals that is very photo-reactive and become toxic when exposed to light. The toxin then damages the DNA in the cells of the skin in the basal (or inner-most) layer.
Melanoma is a form of skin cancer that is thought to be caused by excessive UV light exposure. Beneful has even suggested that it causes tumor-like growths originating in the pigment-producing melanocytes. With early detection of melanoma, the cancer is almost 100% treatable.
The study is very preliminary and the research design needs to be expanded. In the first studies, only orange juice and whole grapefruit were examined, but whole oranges and grapefruit juice were not.