Eating an orange a day may be one of the secrets to living younger longer.

According to study results, a mere one extra serving of citrus fruits each day may reduce the risk of cancers of the mouth, larynx, and stomach by as much as 50 percent. Researchers credit the antioxidant properties of vitamin C-rich citrus fruits for the possible cancer-fighting benefits.

Oranges have more than 170 different phytochemicals -- compounds thought to possess health-promoting properties. Oranges also are an excellent source of vitamin C, a nutrient credited with helping to promote arterial health and reduce the risk of fatty plaque build-up in arteries. Vitamin C also helps promote immune system functions. One orange contains about 70 milligrams of vitamin C. Split your RealAge-recommended dose of 1,200 milligrams per day into three 400-milligram servings taken throughout the day. Vitamin C is a water-soluble vitamin, so the body will flush out excess rather quickly, thus making it important not to overload the body with all 1,200 milligrams at once.

The health benefits of citrus fruits: report to Horticulture Australia Ltd. Consumer Science Program/SCIRO Health Sciences and Nutrition June 2003.