Orange Peels Reduce Melanoma Risk

According to the American Cancer Society Facts and Figures, the most common, serious form of skin cancer is melanoma. While you can take many preventative measures, such as limiting exposure to the sun and wearing sunscreen, you also can reduce your risk by modifying your diet. The juicy pulp found inside the orange contains powerful antioxidants, including a healthy dose of vitamin C. But the high concentration of essential oils and plant chemicals found on the outside of the orange (in the oil glands of the orange peel) also contribute to a healthful diet that can prevent melanoma and other cancers (including breast and pancreatic cancers, some leukemias and neuroblastomas).

The two plant chemicals that have been identified in the orange peel are d-limonene and perillyl alcohol; both belong to the large class of phytochemicals called monoterpenes. While highly concentrated in the essential oils of citrus fruits, the monoterpenes are also present in some herbs (such as mint), some vegetables and other fruits (such as grapefruit and lemon peels).

In a study conducted at the University of Arizona, researchers found that perillyl alcohol is a potent cancer preventive agent. Human skin cells were treated with perillyl alcohol followed by ultraviolet B radiation. The results indicated that numerous genes associated with cancer development were altered in the treated group, suggesting that the compounds found in citrus fruits may protect against cancer. Clinical trials in humans are currently underway.

There is a cancer timeline, often referred to as the “cancer continuum.” The continuum outlines the steps from birth to the day when the cancer is diagnosed and shows specific points at which the three steps in the cancer process (initiation, promotion, progression) can be inhibited or prevented.
The compounds found in orange peels can prevent the cancer process at both the initiation and promotion/progression stages and have been effective in treating early and advanced cancers in rodent models. In addition, d-limonene and perillyl alcohol have been shown to prevent breast, liver, lung, and other cancers and also have been used to treat various rodent cancers, including breast and pancreatic carcinomas.

Orange peels may be an acquired taste, but many people enjoy eating them. An Arizona study reported that 34.7% of the subjects in their study consumed citrus peels regularly and the more they consumed, the greater their protection against abnormal skin growths. Consuming the pulp of the citrus fruit did not produce the same effect.

To get the most out of the peel, you should know how to prepare it. If you don’t have a good microplane, a kitchen tool used to “zest” lemons, limes or orange peels, you should invest in this inexpensive kitchen tool. Orange, lemon and lime zests often are used to make wonderful baked goods, including poppy seed cakes and lemon meringue and key lime pies. But there are more healthful ways to incorporate the abundant protective compounds from these citrus fruits. This recipe was found on Epicurious.com. Simply type in the ingredient you wish to use and several recipes will be found for you to try. Here is one example:

Zested Carrot Zucchini Julienne

1 large carrot
1 large zucchini
1/2 tablespoon unsalted butter
1 teaspoon freshly grated orange zest
1/2 teaspoon freshly grated lemon zest
2 tablespoons slivered almonds, toasted

Preparation
Using a mandoline or other hand-held slicer, cut carrot and zucchini lengthwise into 1/8-inch ribbons. Lay ribbons flat and cut lengthwise into 1/8-inch julienne. In a non-stick skillet heat butter over moderately high heat until foam subsides and saut