Grapefruit juice is the

juice Juice is a drink made from the extraction or Cold-pressed juice, pressing of the natural liquid contained in fruit and vegetables. It can also refer to liquids that are flavored with concentrate or other biological food sources, such as meat ...

from

grapefruit The grapefruit (''Citrus'' × ''paradisi'') is a subtropical citrus tree known for its relatively large, sour to semi-sweet, somewhat bitter fruit. The flesh of the fruit is segmented and varies in color from pale yellow to dark red. Grapefru ...

s. It is rich in

vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits, berries and vegetables. It is also a generic prescription medication and in some countries is sold as a non-prescription di ...

and ranges from sweet-tart to very sour. Variations include white grapefruit, pink grapefruit and ruby red grapefruit juice.The World's Healthiest Foods; Grapefruit. ''The George Mateljan Foundation.'
Article
Grapefruit juice is important in medicine because of its interactions with many common drugs including

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ...

and medications, which can alter how they behave in the body. Grapefruit juice is a common breakfast beverage in the United States.

Drug interactions

Grapefruit and grapefruit juice have been found to interact with numerous

drugs A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via inhalation, injection, smoking, ingestio ...

, in many cases resulting in adverse effects. This happens in two ways: one is that grapefruit can block an

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

which metabolizes medication, and if the drug is not metabolized, then the level of the drug in the blood can become too high, leading to an

adverse effect An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term compli ...

. The other effect is that grapefruit can block the absorption of drugs in the intestine, and if the drug is not absorbed, then not enough of it is in the blood to have a therapeutic effect. One whole grapefruit or a glass of of grapefruit juice can cause drug overdose toxicity. Drugs which are incompatible with grapefruit are typically labeled on the container or

package insert A package insert is a document included in the package of a medication that provides information about that drug and its use. For prescription medications, the insert is technical, providing information for medical professionals about how to pr ...

. People taking drugs can ask their

health care provider A health care provider is an individual health professional or a health facility organization licensed to provide health care diagnosis and treatment services including medication, surgery and medical devices. Health care providers often rece ...

pharmacist A pharmacist, also known as a chemist in English in the Commonwealth of Nations, Commonwealth English, is a healthcare professional who is knowledgeable about preparation, mechanism of action, clinical usage and legislation of medications in ...

questions about grapefruit/drug interactions.

Use in cocktails

Grapefruit juice is used in several

cocktails A cocktail is a mixed drink, usually alcoholic. Most commonly, a cocktail is a combination of one or more spirits mixed with other ingredients, such as juices, flavored syrups, tonic water, shrubs, and bitters. Cocktails vary widely acro ...

, such as the

sea breeze A sea breeze or onshore breeze is a wind that blows in the afternoon from a large body of water toward or onto a landmass. By contrast, a land breeze or offshore breeze is a wind that blows in the night from a landmass toward or onto a large ...

(which consists of grapefruit juice, vodka, and

cranberry juice Cranberry juice is the liquid juice of the cranberry a fruit recognized for its bright red color, tart taste, and versatility for product manufacturing. Major cranberry products include cranberry juice, dried cranberry, cranberry sauce, frozen ...

); the salty dog,David Tanis, ''Heart of the Artichoke and Other Kitchen Journeys'' ( Workman: 2010), p. 320. the grapefruit

mimosa ''Mimosa'' is a genus of about 600 species of herbs and shrubs, in the mimosoid clade of the legume family Fabaceae. Species are native to the Americas, from North Dakota to northern Argentina, and to eastern Africa (Tanzania, Mozambique, and ...

, and a grapefruit radler.

Canadian regulations

Canadian regulations on commercially produced and sold grapefruit juice are that it must be made from clean, mature grapefruit and may contain sugar,

invert sugar Inverted sugar syrup is a syrup mixture of the monosaccharides glucose and fructose, made by splitting disaccharide sucrose. This mixture's optical rotation is opposite to that of the original sugar, which is why it is called an ''invert'' sug ...

, dextrose, glucose solids and class II preservativesclass II preservative
/ref> such as benzoic acid, amylase, cellulase and pectinase. According to Canadian standards, grapefruit juice should contain more than 1.15 milliequivalents of free amino acid per ; more than 70 milligrams of potassium per 100 ml; and have an absorbance value for total polyphenolics of no less than 0.310. During the production process, the sugar content in the juice, before the addition of sugar, invert sugar, dextrose or glucose solids, should have a

Brix Degrees Brix (symbol °Bx) is a measure of the dissolved solids in a liquid, based on its specific gravity, and is commonly used to measure dissolved sugar content of a solution. One degree Brix is 1 gram of sucrose solute dissolved in 100 grams ...

reading of no less than 9.3. It must contain 0.7% to 2.1% of acid by weight as anhydrous citric acid.

References

External links

* {{citrus Fruit juice Grapefruit Citrus drinks CYP3A4 inhibitors

Drug interactions

Use in cocktails

Canadian regulations

See also

References

External links