According to a new study, enjoying a glass of ice-cold lemonade on a sunny afternoon may increase your risk of melanoma, a deadly skin cancer. However, before you chuck out your supply of tangy fruits, be aware that the study had some limitations and must be validated by further research. The findings were published online on June 29 in the Journal of Clinical Oncology.
The study authors note that citrus products are widely consumed foods, which have a high content of psoralens and furocoumarins. The substances belong to a group of naturally occurring chemicals with potential photocarcinogenic (cancer stimulating in the presence of sunlight) properties. Therefore, they conducted a study to assess the risk of malignant melanoma associated with citrus consumption.
The study group comprised 63,810 women enrolled in the Nurses’ Health Study (1984 to 2010) and 41,622 men enrolled in the Health Professionals Follow-Up Study (1986 to 2010). Dietary information was repeatedly evaluated every two to four years during follow-up. Cases of melanoma were identified via self-reporting and confirmed by pathologic records.
The investigators found that during 24 to 26 years of follow-up, they identified 1,840 melanoma cases. After adjustment for other risk factors, the risk of melanoma was: 1.00 for overall citrus consumption less than twice a week (reference), 1.10 (95% CI, 0.94 to 1.30) for two to four times per week; 1.26 for five to six times per week; 1.27 for 1 to 1.5 times per day; and 1.36 for 1.6 or more times per day. In regard to specific products, grapefruit had the greatest association with risk of melanoma *this risk was independent of other lifestyle and dietary factors).
The authors concluded that citrus consumption was associated with an increased risk of malignant melanoma in two groups: males and females. They cautioned, however, that the studt did not prove that citrus consumption was the cause of the cancers. Therefore, the recommended that further studies should be conducted to confirm their findings and explore related health implications.
The authors are affiliated with: Brigham and Women’s Hospital and Harvard Medical School, Boston, MA; Harvard School of Public Health, Boston, MA; Brown University, Providence, RI; and Indiana University, Indianapolis, IN.
A list of the known risk factors compiled by the American Cancer Society is available at this link. Diagnosing melanoma starts with examining a mole or other mark on your skin. Your healthcare provider will examine your skin with the ABCDE rules in mind. This means looking at: Asymmetry (One half of the mole does not match the other half); Border irregularity (The edges of the mole are ragged or irregular; Color (the mole has different colors in it. It may be tan, brown, black, red, or other colors. Or it may have areas that appear to have lost color; Diameter (The mole is bigger than 6 millimeters across, about the size of a pencil eraser. But some melanomas can be smaller; Evolving (A mole changes in size, shape, or color). You should also tell your healthcare provider: when you first noticed it; if it hurts or itches; if it oozes fluid or bleeds, or gets crusty; if it has changed in size, color, or shape. Also inform your healthcare provider whether you have had skin cancer in the past. Also tell him or her whether anyone in your family has had skin cancer.