Boost your Immunity with Citrus Fruits

Citrus fruits benefit the cardiovascular, glandular, digestive/detox­ification, and musculoskeletal immune centers.

On an average day, 50 percent of all Americans eat no fruit at all, according to the USDA. But when they do, they (and perhaps you, too) are likely to reach for an orange. Citrus are surpassed only by apples and bananas in terms of the quantity in which they are pro­duced and eaten—and they’re a good choice. Besides helping pre­vent your next rhinovirus infection, the flavones in oranges reduce LDL (bad) cholesterol and increase the good HDL. All our favor­ite citrus—from street oranges to exotic satsumas—are also rich in vitamin C, folate, potassium, and bone-building vitamin D, as well as capillary-supporting and antiviral bioflavonoids. But that’s not all.

Immunity Benefits

An orange a day provides big nutritional self-defense for four of the body’s immune centers—starting with digestion-maximizing and cholesterol-minimizing fiber.

Easily Digested Fiber. That grapefruit or tangerine beats bacon at breakfast. Unlike meat, which has no fiber and creates waste products during the forty-eight-hour digestion period, high-fiber, fat-free citrus is efficiently digested two hours after you put your grapefruit spoon away, advises Elson Haas, M.D., at the Preventive Medical Center of Marin in California, making citrus a perfect immunity-boosting breakfast starter.

Drink OJ for LDL. According to researchers at the Hebrew Univer­sity of Jerusalem, the flavones in oranges stabilize cholesterol levels so effectively that high cholesterol sufferers might consider upping their intake of oranges before downing statin meds. (But remember, statin meds and most other prescription drugs don’t mix with grape­fruit juice, which increases the effects of many meds.) Citrus fruits like grapefruit also provide pectin, a soluble fiber that helps regulate cholesterol.

Think Citrus, Think Cancer-Fighting. Like tomatoes, red (but not white) grapefruit supplies lycopene, one of the top ten nutrients for fighting off and preventing prostate cancer and heart disease. A grape­fruit supplies more lycopene than do sun-dried tomatoes or sweet red peppers.

According a recent Nurses’ Health Study, women with the highest intake of luteolin, a flavone found in oranges and other citrus (as well as spinach and broccoli) had a 34 percent reduction in ovarian cancer risk, the fourth leading cause of cancer death among women.

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Ascorbic Acid, Plus. Citrus fruit offers four times the vitamin C of bananas and more than three times the ascorbic acid of apples. If it’s organic, you get 30 percent more vitamin C, according to researchers at Truman State University, plus a healthy dose of potassium. Potas­sium helps lower blood pressure and risk of stroke and is in short sup­ply in the traditional diet. If you’re getting your share (2,700 mg to 3,500 mg), you’re probably eating oranges or drinking orange juice, which rank above bananas as a source.

Boosts Iron Absorption. The ascorbic acid in citrus boosts your body’s absorption of non-heme iron found in plants. Having a glass of grapefruit juice before you fork up that spinach salad can help you absorb two to four times as much energizing iron as that salad would supply solo, according to the American Heart Association. The vita­min C in that lemonade or grapefruit also boosts your production of collagen for healthy, youthful-looking skin.

Citrus for Your Cerebellum. All citrus contain flavonoids for stron­ger brain power and a sharper mind. Try a cup of grapefruit sections raw at breakfast sprinkled with soy lecithin granules (for more cerebral muscle) or toss tangerine sections or a few kumquats in your tossed salad at lunch. Do citrus, not Xanax. Up your mood by squeezing a lemon wedge into a glass of water. According to Japanese scientists, the scent of lemon affects a portion of the brain called the cerebel­lum, lifting your spirit and reducing mental fatigue. A whiff of lemon is also said to affect stamina.

Fruit or Juice? A citrus juice like grapefruit juice, says a study by the University of Florida, contains more nutrients per calorie than apples, prunes, grape, or pineapple juices. Oranges have an ORAC rating of 750, surpassed by only eight other fruits. To limit both calories and sugars, choose the tangerine or navel orange over the juice. A glass of OJ adds 110 calories and 20 grams of sugar (as much as a small Almond Joy) to your daily totals. (A warning to people with diabetes: fruit juice raises blood sugar levels faster than a whole citrus does, because the high fiber of the fruit is digested more slowly.) High blood sugar levels make it harder to lose weight and may predispose you to type 2 diabe­tes. A third reason to reach for the whole fruit rather than the carton or can is that processed juices are heated and pasteurized, destroying some of the vitamins A, C, E, and B complex and, just as important, damaging the enzymes that aid in digestion and detoxification.

Sipping (Not Staring at) Our Navels: The Most Nutritious Fruit Juices. On the other hand, according to a report in Pediatrics, chil­dren who drink orange, pineapple, and other fruit juices have higher intakes of potassium, folate, and vitamin C. Oranges are citrus with the highest visibility. But there are plenty of other-than-oranges citrus worth bringing home. Consider other members of this large extended family:

  • Blood orange (including Ruby Red, Moro, and Tarocco)
  • Mandarin oranges (satsumas and clementines)
  • Tangelos (a cross between the mandarin and the grapefruit)
  • Ugli fruit (outsized tangelos from Jamaica)
  • Murcott (a cross between the tangerine and the sweet orange)
  • Grapefruit (white, pink, red, and golden)
  • Pomelo (Chinese grapefruit)
  • Lemons (including Eureka, Lisbon, and Meyer)
  • Limes (including Persian, Kaffir, and Mandarin)
  • Kumquat, almost the only citrus with an edible skin (The Meyer lemon can be eaten whole but probably rarely is.)

There are even the sour tangerine-sized Japanese yuzu, the limequat, and the lemonquat among the oddball citrus.

Buying, Storing, and Preparing

  • Eat locally grown citrus. Citrus fruits imported from other coun­tries are invariably fumigated, and all the travel miles leave a big carbon footprint.
  • Pick fruit that is ripe, small, thin-skinned, but heavy for its fruit. If organic, don’t demand cosmetic perfection.
  • Think twice about commercial oranges that may have been dyed red to appear ripe and waxed (thus trapping pesticide residues) for a longer shelf life. Nonorganic citrus is sprayed with fifty dif­ferent pesticides, and traces always remain.
  • Avoid green oranges. They’re less sweet because they haven’t matured, are lower in vitamin C, and may aggravate existing joint pain.
  • Chill your citrus to keep it fresh, but bring it to room temperature before eating or cooking with it.
  • Wash with a vegetable wash or rinse with hydrogen peroxide (one tablespoon to a quart of water) before eating to remove mold, bacteria, and pesticide residue (if commercial).

About the author

Many tips are based on recent research, while others were known in ancient times. But they have all been proven to be effective. So keep this website close at hand and make the advice it offers a part of your daily life.