Grapefruit: Healthy for Whom?


Grapefruit Classification:

Citrus ×paradisi Macfad. (pro sp.) [maxima × sinensis]
CTRL + Click on a scientific name below to expand it in the PLANTS Classification Report.

//Plantae// – Plants
//Tracheobionta// – Vascular plants
//Spermatophyta// – Seed plants
//Magnoliophyta// – Flowering plants
//Magnoliopsida// – Dicotyledons
//Rutaceae// – Rue family
//Citrus// L. – citrus
//Citrus// ×//paradisi// Macfad. (pro sp.) [//maxima// × //sinensis//] – grapefruit

Grapefruit Plant Description:

The grapefruit (Citrus X paradisi) is a fruit produced by a subtropical citrus tree belonging to the family Rutaceae, which contains all of the citrus fruits. The fruit is generally believed to be a relatively recent hybrid, probably originating in Barbados, where it was first documented in 1750. It seems to have resulted from a cross between two citrus fruits, the Indonesian Pomelo and the Southeast Asian sweet orange (Mateljan, 2007, p. 390) (Wikipedia: Grapefruit, History). Citrus fruits are generally believed to have originated in Southeast Asia, especially in the area comprising Burma, Northeast India, and Southern China. Because of the many trade routes in the ancient world, citrus cultivation quickly began to spread into the Middle East and Europe. Because of the way citrus fruits apparently radiated out from Southeast Asia, their taxonomy is complicated and the precise number of natural species is still unclear. Many of the named species are hybrids, deliberately produced by artificial selection, and there is genetic evidence that even some of the wild, true-breeding species are of hybrid origins. Indeed, there may have been only four ancestral species in the wild (Wikipedia: Grapefruit, History).

The Grapefruit Tree:

The grapefruit tree reaches 15-20 feet on average, occasionally growing up to 45 feet in height. It has a rounded top of spreading branches, and its twigs are normally covered with short, pliable thorns. The leaves are evergreen, ovate in shape, three to six inches long and one and three quarters to three inches wide. The leaves are dark green above, lighter green below, and have rounded teeth along the margins. The leaves also contain minute oil glands. The tree bears small, white dicot flowers, each with four petals, which may appear singly or in clusters in the leaf axils (Grapefruit, Morton, 1987).

The fruit itself is round to oblate in shape, four to six inches wide, with a smooth rind up to three eighth inches thick. The rind is usually pale yellow, but sometimes exhibits traces of pink. The pulp of the fruit can be nearly whitish (blond), pink, or deep-red, and is divided into eleven to fourteen segments with thin, membranous, bitter-tasting walls. Depending on the color of the pulp, the taste can range in flavor from strongly acidic to sweet-acidic upon maturity. The fruit, sometimes produced in seedless varieties, may contain up to fifty white, elliptical pointed seeds. The number of fruits in a cluster can be anywhere from twelve to twenty (Morton, 1987). Like oranges, lemons, and limes, the grapefruit is a Hesperidium, that is to say, it is technically a berry with a tough leathery outer skin, or rind. The name, Grapefruit, was first used in 1814 and reflected the way the fruit developed on trees in grape-like clusters (Levetin & McMahon, 2007, p. 89, 99).

Grapefruit Distribution:


Presently, the grapefruit is grown in many parts of the world, the top ten producers being the United States (Florida, Texas, Arizona, and California), China, South Africa, Mexico, Syria, Israel, Turkey, India, Argentina, and Cuba. First introduced into the United States in 1823, the grapefruit did not become an important commercial item until the late 19th century, when a wealthy businessman, Chase Atwood, founded the Atwood Grapefruit Company and established the largest grapefruit grove in the world. Here, the first pink variety was discovered in 1906, and red (ruby) variants were subsequently developed using radiation-induced mutations (Wikipedia: Grapefruit, History and Production).

About one half of the world's total output of grapefruits originates in the United States, and the American grapefruit industry has aggressively pursued global markets through bilateral and multilateral accords. Up to now, the industry has been quite successful by means of this strategy (Thornsbury and Spreen, 2000). World grapefruit production is about four million tons, ninety percent of which is produced by countries in the northern hemisphere such as the United States, Cuba, and Israel. Israel is the second greatest exporter behind the United States. In the southern hemisphere, Argentina is the greatest grapefruit producer yielding about 200,000 tons, with pink and red dominating (Made in Argentina, "World Production of Grapefruit," 2010). The high heat requirement for growing grapefruit severely limits the number of regions capable of producing high quality grapefruits. Because all four states in North America are susceptible to winter freezes, grapefruit supply in the United States has always been vulnerable to weather-related problems linked to frost or freeze conditions. Such conditions can lead to the total death of grapefruit trees, which has led growers in Florida to shift most of their growing sites to the southern part of the state. Most grapefruit trees only begin to yield fruit after three years, so it takes time to recover from the loss of trees. Trees normally produce at peak level for about twenty years (Thornsbury and Spreen, 2000).

Nutritional Facts about the Grapefruit:

Grapefruits are extremely nutritious, being especially rich in vitamin C while also containing dietary fiber, potassium, and vitamins A and B-5 (Mateljan, p. 390; George Mateljan Foundation (2007): Grapefruit, paras. 1-3). Grapefruit also has numerous properties very beneficial to human health. The lycopene that accounts for its color is an antioxidant and has been shown to inhibit the growth of tumors. Grapefruit juice itself is ranked as one of the most powerful juices in terms of antioxidant activity. Combined with green tea, grapefruits greatly reduce the risk of prostate cancer in men. Grapefruits also contain pectin, a soluble fiber that reduces LDL’s and slows down the development of atheroscelrosis. In addition, phytonutrients in grapefruits, in particular the limonoids, have been shown in lab studies using animals and human cells to be effective in fighting cancers of the mouth, skin, lung, breast, stomach, and colon. Grapefruit juice also lowers the risk of kidney stones (George Mateljan Foundation: Grapefruit, paras. 4-39). Researchers in Israel have recently found that red and white grapefruits contain powerful antioxidants that significantly reduce cholesterol levels by about fifteen percent and triglyceride levels by seventeen percent. A study conducted by Chinese researchers in 2006 found that Naringenin, a plant compound found in grapefruit, helped repair damaged genetic material in human prostate cancer cells. DNA repair is obviously of extreme importance since it prevents cancer cells from multiplying. The Scripps Clinic in San Diego found that consuming one half of a grapefruit resulted in an average weight loss of 3.6 pounds over a twelve week period ("Grapefruit are Great Fruits," n.d.). Grapefruit is very low in sodium and high in fat-burning enzymes, which helps flush out excess water from the body that is retained from high sodium diets. Grapefruits have also been found to help patients suffering from indigestion since grapefruits are considered a light food. In addition, grapefruits can also increase the activity and production of liver enzymes that help detoxify by eliminating toxic compounds from the body, including carcinogenic substances ("Grapefruit Benefits," 2006). And the list of beneficial just seems to go on and on....

Wild Card

Grapefruit: Healthy for Whom?

Is grapefruit, then, really a perfect “health” fruit? Unfortunately, for many people on medications, the answer is no. Grapefruit products can interfere with a key enzyme, cytochrome P450 3A4, that normally metabolizes medications in the digestive system. Instead of breaking down the medications, the enzyme concentrates on breaking down the grapefruit products; the higher the concentration of grapefruit products, the less time the enzyme spends on metabolizing medications. This leads to a rise in the level of potent medications in the body, almost as if the patient is overdosing on his or her medications, with sometimes fatal side-effects. An article from the University of Rochester Medical Center cites the case of a patient who was on Lipitor because of high cholesterol. Moving to Florida for the winter, the patient began drinking several glasses of grapefruit juice per day, extracting the juice from grapefruits growing in his backyard. Soon, suffering from muscle pain, fever, and general fatigue, he went to the emergency room of a local hospital, where he soon thereafter died of kidney failure (“Grapefruit Juice and Medication Can Be a Dangerous Mix,” n.d.). Over 50 different medications have the potential to be affected by grapefruit products, including such popular medicines as Zoloft (anti-depressant), Allegra (anti-histamine) and Lipitor (statin) (“Grapefruit Juice and Medication Can Be a Dangerous Mix,” n.d.) (Zeratsky, 2011). In fact, most of these medications are widely used today because they treat common problems such as high cholesterol, depression, high blood pressure, cancer, pain, impotence, and allergies. The exact chemicals in grapefruit that cause these deadly interactions are still not all known, but they are present not only in grapefruit juice, but in the pulp and rind as well, and they can affect medications up to 72 hours after grapefruit has been consumed. Pharmacist Barbara Mendez notes that "eating certain foods while taking certain drugs can change the medications effectiveness, so you may get more or less than prescribed" (Jacobs, 2011). A cardiologist with Midwest Heart Specialists, Dr. Joseph Marek, goes even further and says: “Our advice is play it safe and avoid grapefruit in any form.” (Midwest Heart Specialists, 2008).

So, while grapefruit is an extremely healthy food for those not on medications, it can be deadly and anything but “healthy” for those on many of our most popular medications.

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