The grapefruit was first described in the 1750s as the "forbidden fruit" of Barbados. It was introduced to Florida in the 1820s. Most grapefruit in the United States is still grown in Florida. Grapefruit juice has been used in folk medicine for the treatment of diabetes as well as to strengthen the immune system. Grapefruit is also added to cosmetics and hair care products as a fragrance.
Grapefruit has been suggested as a treatment for several conditions, but there is currently insufficient scientific evidence to support the use of grapefruit for any medical disorder. The use of supplemental grapefruit pectin in the prevention of cardiovascular disease and the use of grapefruit seed extract in atopic eczema warrants further scientific investigation before a strong recommendation can be made. There is conflicting research regarding the use of grapefruit for kidney stones.
Grapefruit juice alters the way some drugs are broken down in the liver. Grapefruit may increase the effects of calcium channel blockers, benzodiazepines, immunosuppressants, and HMG-CoA reductase inhibitors.

Related Terms

Antioxidizers, bergamottin, bergapten, bergaptol, blond grapefruits, citricidal, Citrus decumana, Citrus maxima, Citrus paradisi, Citrus paradisi Macf., Citrus paradisi Macfayden, Citrus x paradisi, citrus seed, citrus seed extract, flavonoids, Fresca®, furanocoumarins, geranylcoumarin, grapefruit juice, grapefruit pectin, grapefruit seed, grapefruit seed extract, naringenin, naringin, nootkatone, organic grapefruit juice, paradisapfel, ParaMicrocidin®, pomelo, pummelo grapefruit, red grapefruit, Red Mexican grapefruit, Rio Red Grapefruit, rutacea, sesquiterpen, shaddock oil, Sun Drop®, toronja, vitamin C, white grapefruit.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Atopic eczema (Grade: C)
There is early, but inconclusive evidence to support the use of grapefruit seed extract in the treatment of atopic eczema. Additional study is needed to confirm these findings.
Endocrine disorders (metabolic syndrome) (Grade: C)
Early studies suggest grapefruit may have some benefit in the management of metabolic syndrome. More studies are needed to understand this relationship.
Heart disease (Grade: C)
Grapefruit pectin supplementation may inhibit high cholesterol. There is promising but inconclusive human evidence to support the use of grapefruit pectin in the prevention of heart disease. Additional study is needed in this area.
Kidney stones (Grade: C)
There is limited and mixed research regarding the use of grapefruit for kidney stones. Further research is needed to clarify these results.