Citrus fruit and melanoma have a potential cancer link as a result of the data reviewed in two long-term studies. Melanoma is the deadliest of skin cancer, the fifth most common in the United States, and sixth in the world. According to the Center for Disease Control (CDC), it is estimated that more than 9,000 people die of melanoma each year.
Data was collected by the Nurse’s Health and the Health Professionals Follow-up Studies from 63,000 women and 41,000 men, between the mid-1980s and 2010, to determine an association between citrus fruit and malignant melanoma. Information collected included the effects of dietary patterns, history of sunburn, overall sun exposure, smoking habits, and self-reports of melanoma diagnosis provided in confirmed medical records.
All the results are providing a preliminary view and currently interpreted with caution due to the small scale representation of the United States population. Additionally, more data of replicated studies are needed to determine whether skin cancer, specifically, is caused by citrus fruits.
The citrus consumption categories included grapefruit, oranges, and the juices from both of these fruits. Orange juice was a strong candidate for the studies because it is consumed more often than grapefruit. Lemons and limes were not selected to be on this particular list for the study.
Over a twenty year period of time, 1,840 cases of melanoma were noted. A comparison was made between the participants who consumed the fruit less than twice a week and those eating two to four times a week.
The risk of melanoma increased by 10 percent for those eating the fruit two to four times per week, and there was an increase of 36 percent for those who ate this fruit more than 1.5 times per day. Researchers stated that there is a chemical explanation for these conclusions.
Citrus fruit and melanoma have a potential link to cancer due to furocoumarins, which are compounds that make the skin more sensitive. The exposure to the sun may cause more damage to the skin cells.
Another compound important to this study is psoralen, which was used in tanning lotions in 1996. It was discovered that there are more furocoumarins and psoralen compounds in the actual grapefruit than in its juice. Together, with furocoumarins, the psoralen can interact with the ultraviolet rays.
One confusing aspect of this study is that people who consumed more grapefruits and drank more orange juice were at a higher risk of skin cancer. However, the people who drank the grapefruit juice and ate whole oranges appeared to have a lower risk. The study identified a serving as a six-ounce glass of juice, a half grapefruit, or one orange.
Researchers from the Journal of Clinical Oncology supported the importance of providing more information due to inconsistencies that need to provide standardized data procedures. It is too early to ask people to lower their intake of citrus fruits or make any strict dietary changes, nevertheless, consumers must be warned of the cancer potential. Eating a variety of foods and doing so in moderation has been recommended. Protecting the skin from excessive exposure is, also, an another important precaution.
Understanding the sunscreen protection factor (SPF) is valuable knowledge for consumers. The term “broad spectrum” is an ingredient consumers must note on labels of sunscreen products. Read Sunscreen Labels Confuse Consumers for more information.
By Marie A. Wakefield
Reuters -Citrus Fruit Linked With Melanoma in Preliminary Study
NBC News – Could Too Much Citrus Cause Skin Cancer?
CBS News – Could Orange Juice, Grapefruit Raise Skin Cancer Risk?
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