The World's Healthiest Foods
Grapefruit

Tart and tangy with an underlying sweetness, grapefruit has a juiciness that rivals that of the ever popular orange and sparkles with many of the same health promoting benefits. Although available throughout the year, they are in season and at their best from winter through early spring.

Grapefruits usually range in diameter from four to six inches and include both seed and seedless and pink and white varieties. The wonderful flavor of a grapefruit is like paradise as is expressed by its Latin name, Citrus paradisi.

 


Health Benefits

Grapefruit may be the less favored citrus choice when compared to its sweeter cousin, the orange, but grapefruit sparkles with health promoting compounds that may help:

  • fight cold symptoms
  • prevent certain forms of cancer
  • prevent heart disease

Vitamin C

Grapefruit is an excellent source of vitamin C, a vitamin that helps to support the immune system. Vitamin C-rich foods like grapefruit may help reduce cold symptoms or severity of cold symptoms; over 20 scientific studies have suggested that vitamin C is a cold-fighter. Vitamin C also prevents the free radical damage that triggers the inflammatory cascade, and is therefore also associated with reduced severity of inflammatory conditions, such as asthma, osteoarthritis, and rheumatoid arthritis. As free radicals can oxidize cholesterol and lead to plaques that may rupture causing heart attacks or stroke, vitamin C is beneficial to promoting cardiovascular health. Owing to the multitude of vitamin C's health benefits, it is not surprising that research has shown that consumption of vegetables and fruits high in this nutrient is associated with a reduced risk of death from all causes including heart disease, stroke and cancer.

Protection against Lung and Colon Cancer

Not only are grapefruit rich in vitamin C, but new research presented August 2004 at the 228th National Meeting of the American Chemical Society provides two more reasons to drink grapefruit juice: protection against lung and colon cancer.

In humans, drinking three 6-ounce glasses of grapefruit juice a day was shown to reduce the activity of an enzyme that activates cancer-causing chemicals found in tobacco smoke. In rats whose colons were injected with carcinogens, grapefruit and its isolated active compounds (apigenin, hesperidin, limonin, naringin, naringenin, nobiletin) not only increased the suicide (apoptosis) of cancer cells, but also the production of normal colon cells. Researchers also confirmed that grapefruit may help prevent weight gain by lowering insulin levels. (October 19, 2004)

Lycopene

The rich pink and red colors of grapefruit are due to lycopene, a carotenoid phytochemical. Lycopene appears to have anti-tumor activity. Among the common dietary carotenoids, lycopene has the highest capacity to help fight oxygen free radicals, which are compounds that can damage cells.

Limonoids

Phytochemicals in grapefruit called limonoids inhibit tumor formation by promoting the formation of glutathione-S-transferase, a detoxifying enzyme. This enzyme sparks a reaction in the liver that helps to make toxic compounds more water soluble for excretion from the body. Pulp of citrus fruits like grapefruit contain glucarates, compounds which may help prevent breast cancer.

Pectin

Grapefruit contains pectin, a form of soluble fiber that forms a gel-like substance in the intestinal tract that can trap fats like cholesterol. In animal studies, grapefruit pectin inhibited the formation of atherosclerosis. Animals fed a high-cholesterol diet plus grapefruit pectin had 24% narrowing of their arteries, while animals fed only the high-cholesterol diet had 45% narrowing.

Prevent Kidney Stones

Want to reduce your risk of calcium oxalate kidney stones? Drink grapefruit juice. A study published in the August 2003 issue of the British Journal of Nutrition found that when women drank ½ to 1 litre of grapefruit, apple or orange juice daily, their urinary pH value and citric acid excretion increased, significantly dropping their risk of forming calcium oxalate stones.(Ocftober 4, 2003)

Protection against Macular Degeneration

Your mother may have told you carrots would keep your eyes bright as a child, but as an adult, it looks like fruit is even more important for keeping your sight. Data reported in a study published in the June 2004 issue of the Archives of Opthamology indicates that eating 3 or more servings of fruit per day may lower your risk of age-related macular degeneration (ARMD), the primary cause of vision loss in older adults, by 36%, compared to persons who consume less than 1.5 servings of fruit daily.

In this study, which involved 77,562 women and 40,866 men, researchers evaluated the effect of study participants' consumption of fruits; vegetables; the antioxidant vitamins A, C, and E; and carotenoids on the development of early ARMD or neovascular ARM, a more severe form of the illness associated with vision loss. Food intake information was collected periodically for up to 18 years for women and 12 years for men. While, surprisingly, intakes of vegetables, antioxidant vitamins and carotenoids were not strongly related to incidence of either form of ARM, fruit intake was definitely protective against the severe form of this vision-destroying disease. Three servings of fruit may sound like a lot to eat each day, but grapefruit can help you reach this goal. Try starting your day with a half grapefruit, add grapefruit sections to your green salads, or for an elegant dessert, spread a little honey over a half grapefruit and broil for 1-2 minutes.(July 10, 2004)

Description

The grapefruit is a large citrus fruit related to the orange, lemon and pomelo. Grapefruits are categorized as white, pink or ruby. However, this terminology doesn't reflect their skin color, which is either yellow or pinkish-yellow, but rather describes the color of their flesh.

Grapefruits usually range in diameter from four to six inches, with some varieties featuring seeds while others are seedless. The wonderful flavor of a grapefruit is like paradise, just as its Latin name Citrus paradisi connotes. It is juicy, tart and tangy with an underlying sweetness that weaves throughout.

History

Grapefruits have a rather recent history, having been discovered in Barbados in the 18th century. Many botanists think the grapefruit was actually the result of a natural cross breeding which occurred between the orange and the pomelo, a citrus fruit that was brought from Indonesia to Barbados in the 17th century.

The resulting fruit was given the name “grapefruit” in 1814 in Jamaica, a name which reflects the way it's arranged when it grows – hanging in clusters just like grapes.

Grapefruit trees were planted in Florida in the early 19th century, although they did not become a viable commercial crop until later that century. Florida is still a major producer of grapefruits, as is California, Arizona and Texas. Other countries that produce grapefruits commercially include Israel, South Africa and Brazil.

How to Select and Store

How to Enjoy

Tips for preparing grapefruit:

Tips for preparing grapefruit:

Grapefruits should be rinsed under cool water before consuming, even though you will probably not be eating the peel, since cutting into an unwashed fruit may transfer dirt or bacteria that may reside on the skin’s surface to the edible flesh.

Grapefruits are usually eaten fresh by slicing the fruit horizontally and scooping out sections of the halves with a spoon. To separate the flesh from the membrane you can either cut it with a sharp knife, a special curved-blade grapefruit knife, or a serrated grapefruit spoon. If there are seeds, you can remove them with your spoon before you eat.

Grapefruits can also be eaten like oranges. You can peel them with your hands or with a knife. If choosing the latter method, starting at the top, make a vertical incision that runs downward and then back up to the top on the other side and then repeat so that there will be four sections of similar size.

Be careful to only cut through skin and not into the membrane. The skin can then be peeled back with your hands or with the knife. The membranes can be separated, as you would do to an orange eaten in this manner.

Another way to serve grapefruit is to peel and slice them.

A few quick serving ideas:

Grapefruit sections add a tangy spark to green salads.

Instead of your morning glass of OJ, have a glass of grapefruit juice.

Combine diced grapefruit with cilantro and chili peppers to make a unique salsa.

To enjoy a salad with a tropical flair, combine chopped grapefruit pieces, cooked shrimp and avocadoes and serve on a bed of romaine lettuce.

Safety

Check with your healthcare practitioner if you're taking pharmaceutical drugs with grapefruit juice. Certain pharmaceutical drugs combined with grapefruit juice become more potent. Compounds in grapefruit juice, including naringenin, slow the normal detoxification and metabolism processes in the intestines and liver, which hinders the body's ability to breakdown and eliminate these drugs. These interactive drugs include the immunosuppressent cyclosporine and calcium channel blocker drugs, such as felodipine, nifedipine and verapamil. Other drugs enhanced by grapefruit juice are the antihistamine terfenadine, the hormone estradiol and the antiviral agent saquinavir.

Research also indicates that individuals taking statin drugs should avoid grapefruit. Grapefruit increases the amount of statin drug that reaches the general circulation in two ways. First, grapefruit contains a compound called naringenin, which inactivates an enzyme (cytochrome P450 3A4) in the small intestine that metabolizes statin drugs. Secondly, grapefruit also inhibits P-glycoprotein, a carrier molecule produced in the intestinal wall that would normally transport the statin drug back to the gut. The end result of these two mechanisms is that much more of the statin drug enters the systemic circulation than would normally be the case, leading to a build up in statin levels that can be quite dangerous, and may trigger a rare but serious statin-associated disease called rhabdomyolysis. Rhaddomyolysis affects muscle tissue, usually causing temporary paralysis or weakness, unless the muscle is severely injured. (March 25, 2004)

Virtually all municipal drinking water in the United States contains pesticide residues, and with the exception of organic foods, so do the majority of foods in the U.S. food supply. Even though pesticides are present in food at very small trace levels, their negative impact on health is well documented.

The liver’s ability to process other toxins, the cells’ ability to produce energy, and the nerves’ ability to send messages can all be compromised by pesticide exposure. Individuals wanting to avoid these health risks may want to avoid consumption of grapefruit unless grown organically, since grapefruit is among the 20 foods on which pesticide residues have been most frequently found.

Nutritional Profile

Introduction to Food Rating System Chart

The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents (similar to other information presented in the website, this DV is calculated for 25-50 year old healthy woman); the nutrient density rating; and, the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. For more detailed information on our Food and Recipe Rating System, please click here.

 

Grapefruit
0.50 each
60.00 calories
Nutrient Amount DV
(%)
Nutrient
Density
World's Healthiest
Foods Rating
vitamin C 66.00 mg 110.0 33.0 excellent
vitamin A 750.00 IU 15.0 4.5 very good
dietary fiber 2.70 g 10.8 3.2 good
potassium 230.00 mg 6.6 2.0 good
World's Healthiest
Foods Rating
Rule
excellent DV>=75% OR Density>=7.6 AND DV>=10%
very good DV>=50% OR Density>=3.4 AND DV>=5%
good DV>=25% OR Density>=1.5 AND DV>=2.5%

References

  • Cerda JJ, Normann SJ, Sullivan MP, et al. Inhibition of atherosclerosis by dietary pectin in microswine with sustained hypercholesterolemia. Circulation 1994 Mar;89(3):1247-53.
  • Cho E, Seddon JM, Rosner B, Willett WC, Hankinson SE. Prospective study of intake of fruits, vegetables, vitamins, and carotenoids and risk of age-related maculopathy. Arch Ophthalmol. 2004 Jun;122(6):883-92.
  • Craig W. Phytochemicals: guardians of our health. J Am Diet Assoc. 1997;97(Suppl 2) S199-S204.
  • Dahan A, Altman H. Food-drug interaction: grapefruit juice augments drug bioavailability--mechanism, extent and relevance. Eur J Clin Nutr. 2004 Jan;58(1):1-9.
  • Dreier JP, Endres M. Statin-associated rhabdomyolysis triggered by grapefruit consumption. Neurology. 2004 Feb 24;62(4):670.
  • Ensminger AH, Esminger M. K. J. e. al. Food for Health: A Nutrition Encyclopedia. Clovis, California: Pegus Press; 1986.
  • Honow R, Laube N, Schneider A, Kessler T, Hesse. Influence of grapefruit-, orange- and apple-juice consumption on urinary variables and risk of crystallization. Br J Nutr. Aug;90(2):295-300.
  • Khaw KT, Bingham S, Welch A, et al. Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition. Lancet. 2001 Mar 3;357(9257):657-63.
  • Kurl S, Tuomainen TP, Laukkanen JA et al. Plasma vitamin C modifies the association between hypertension and risk of stroke. Stroke 2002 Jun;33(6):1568-73.
  • Mahan LK, Stump S. Krause's Food Nutrition and Diet Therapy 10th Ed. WB Saunders Co 2000.
  • Matos HR, Di Mascio P, Medeiros MH. Protective effect of lycopene on lipid peroxidation and oxidative DNA damage in cell culture. Arch Biochem Biophys 2000 Nov 1;383(1):56-9.
  • Murray M. Encyclopedia of Nutritional Supplements. Prima Publishing 1996.
  • Suzuki, Kohno H, Sugie S, Murkami A, Yano M, Ohigashi H, Tanaka T. Citrus nobiletin inhibits azoxymethane-inducved rat colon carcinogenecis. The 228th ACS National Meeting, Philadelphia, PA, August 24, 2004.
  • Thompson PD, Clarkson P, Karas RH. Statin-associated myopathy. JAMA. 2003 Apr 2;289(13):1681-90.
  • Turner, Vanamala J, Leonardi T, Patil B, Murphy M, Wang N, Pike L, et al. Grapefruit and its isolated bioactive compounds act as colon cancer chemoprotectants in rats. The 228th ACS National Meeting, Philadelphia, PA, August 24, 2004.
  • Wood, Rebecca. The Whole Foods Encyclopedia. New York, NY: Prentice-Hall Press; 1988.

This page was updated on: 2004-11-20 13:08:39
© 2002 The George Mateljan Foundation