It's common knowledge that citrus fruit — including oranges, tangerines and grapefruits — are high in vitamin C. With the changing of seasons, the fluctuation of temperatures may be cause for the common cold. Citrus' cold-fighting abilities are well-documented, and it's nature's miracle that these fruits reach their peak during the virus-prone transitional months. But the cold-fighting power of citrus is but one of its myriad health virtues.
Reduces Risk of Disease
For starters, the abundant vitamin C in citrus — one orange contains 116.2 percent of the daily allowance—reduces not just cold symptoms but also the risk of cardiovascular and inflammatory disease. The vitamin prevents free radical damage to cells, which is responsible for the inflammation associated with conditions like rheumatoid arthritis and for the oxidation of cholesterol which can lead to clogged arteries. A vitamin C-rich diet also lowers the likelihood of developing H. pylori infection, the bacterium responsible for peptic ulcers.
Aside from vitamin C, citrus fruit is chock full of phytonutrients and fiber that may lower cholesterol. Herperidin, a flavonoid found in the peel and white inner pulp of oranges, lowered cholesterol in animal studies. Compounds in orange and tangerine peel have been shown to lower LDL cholesterol as effectively as statin drugs. Pectin, a soluble fiber in grapefruit, cut the risk of developing narrowed arteries in half, during a study of animals fed high-cholesterol diets. In a study with human subjects, both blond and ruby red grapefruit lowered LDL cholesterol, though ruby red proved to be more than twice as effective as blond and lowered triglycerides as well.
Pink and ruby red grapefruits may owe their edge to lycopene, a carotenoid that lends them their rosy color. Lycopene is a potent cancer-fighter, especially in the case of prostate cancer. In one study, men who regularly consumed lycopene-rich foods were 82 per cent less likely to develop prostate cancer. The orange-red pigment that colors oranges and tangerines also has cancer-fighting properties. It has been shown to lower the risk of developing lung cancer, especially among smokers. Grapefruit, too, may protect smokers; in one study, drinking three six-ounce glasses of grapefruit juice daily reduced the activity of an enzyme that activates cancer-causing chemicals found in tobacco smoke.
Diets high in citrus appear to have a protective effect against a host of other cancers as well. The pulp of citrus contains compounds that appear to help prevent breast cancer. Liminoids, phytonutrients found in oranges and grapefruits, help guard against cancers of the mouth, skin, stomach, and colon. They may inhibit tumor formation by increasing a key detoxifying enzyme that helps the body excrete toxic compounds. The detoxifying properties may also account for the reduced risk of kidney stones associated with regular consumption of orange or grapefruit juice.
Citrus fruits are also high in folate and potassium, nutrients essential for cardiovascular health. Folate lowers levels of homocysteine, a marker for cardiovascular risk. Potassium keeps blood pressure in check, guarding against stroke. In fact, studies show that consuming one serving of citrus fruit a day amounts to a nineteen-percent reduction in stroke risk.
With all of these phenomenal benefits, it's clear that those who already have their daily glass of orange or grapefruit juice shouldn't take it for granted. Prior to the 20th century, citrus fruit was an expensive delicacy consumed only on special occasions. Today, with the affordability of abundant citrus and all the gifts it gives your body, every day can be an occasion.