Grapefruit juice is the juice from grapefruits. It is rich in vitamin C and ranges from sweet-tart to very sour. Variations include white grapefruit, pink grapefruit and ruby red grapefruit juice. [1] [2]
Grapefruit juice is important in medicine because of its interactions with many common drugs including caffeine and medications, which can alter how they behave in the body.
Grapefruit juice is a common breakfast beverage in the United States. [3]
Grapefruit and grapefruit juice have been found to interact with numerous drugs, in many cases resulting in adverse effects. [4] This happens in two ways: one is that grapefruit can block an enzyme which metabolizes medication, [5] 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. [5] The other effect is that grapefruit can block the absorption of drugs in the intestine, [5] and if the drug is not absorbed, then not enough of it is in the blood to have a therapeutic effect. [5]
One whole grapefruit or a glass of 200 mL (6.8 US fl oz) of grapefruit juice can cause drug overdose toxicity. [4] Drugs which are incompatible with grapefruit are typically labeled on the container or package insert. [5] People taking drugs can ask their health care provider or pharmacist questions about grapefruit/drug interactions. [5]
Grapefruit juice is used in several cocktails, such as the sea breeze (which consists of grapefruit juice, vodka, and cranberry juice); [6] the salty dog, [7] the grapefruit mimosa, [7] and a grapefruit radler. [8]
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, dextrose, glucose solids and class II preservatives [9] such as benzoic acid, amylase, cellulase and pectinase. [10] According to Canadian standards, grapefruit juice should contain more than 1.15 milliequivalents of free amino acid per 100 millilitres (3.5 imp fl oz; 3.4 US fl oz); more than 70 milligrams of potassium per 100 ml; and have an absorbance value for total polyphenolics of no less than 0.310. [10] 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 reading of no less than 9.3. It must contain 0.7% to 2.1% of acid by weight as anhydrous citric acid. [10]
Sucralose is an artificial sweetener and sugar substitute. The majority of ingested sucralose is not broken down by the body, so it is noncaloric. In the European Union, it is also known under the E number E955. It is produced by chlorination of sucrose, selectively replacing three of the hydroxy groups—in the C1 and C6 positions of fructose and the C4 position of glucose—to give a 1,6-dichloro-1,6-dideoxyfructose–4-chloro-4-deoxygalactose disaccharide. Sucralose is about 320 to 1,000 times sweeter than sucrose, three times as sweet as both aspartame and acesulfame potassium, and twice as sweet as sodium saccharin.
Orange juice is a liquid extract of the orange tree fruit, produced by squeezing or reaming oranges. It comes in several different varieties, including blood orange, navel oranges, valencia orange, clementine, and tangerine. As well as variations in oranges used, some varieties include differing amounts of juice vesicles, known as "pulp" in American English, and "(juicy) bits" in British English. These vesicles contain the juice of the orange and can be left in or removed during the manufacturing process. How juicy these vesicles are depend upon many factors, such as species, variety, and season. In American English, the beverage name is often abbreviated as "OJ".
Sorbitol, less commonly known as glucitol, is a sugar alcohol with a sweet taste which the human body metabolizes slowly. It can be obtained by reduction of glucose, which changes the converted aldehyde group (−CHO) to a primary alcohol group (−CH2OH). Most sorbitol is made from potato starch, but it is also found in nature, for example in apples, pears, peaches, and prunes. It is converted to fructose by sorbitol-6-phosphate 2-dehydrogenase. Sorbitol is an isomer of mannitol, another sugar alcohol; the two differ only in the orientation of the hydroxyl group on carbon 2. While similar, the two sugar alcohols have very different sources in nature, melting points, and uses.
The grapefruit is a subtropical citrus tree known for its relatively large, sour to semi-sweet, somewhat bitter fruit. The interior flesh is segmented and varies in color from pale yellow to dark pink/red.
In cooking, syrup is a condiment that is a thick, viscous liquid consisting primarily of a solution of sugar in water, containing a large amount of dissolved sugars but showing little tendency to deposit crystals. In its concentrated form, its consistency is similar to that of molasses. The viscosity arises from the multiple hydrogen bonds between the dissolved sugar, which has many hydroxyl (OH) groups.
The pomelo, from the family Rutaceae, is the largest citrus fruit, and the principal ancestor of the grapefruit. It is a natural, non-hybrid, citrus fruit, native to Southeast Asia. Similar in taste to a sweet grapefruit, the pomelo is commonly consumed and used for festive occasions throughout Southeast Asia and East Asia. As with the grapefruit, phytochemicals in the pomelo have the potential for drug interactions.
Cytochrome P450 3A4 is an important enzyme in the body, mainly found in the liver and in the intestine. It oxidizes small foreign organic molecules (xenobiotics), such as toxins or drugs, so that they can be removed from the body. It is highly homologous to CYP3A5, another important CYP3A enzyme.
In pharmaceutical sciences, drug interactions occur when a drug's mechanism of action is affected by the concomitant administration of substances such as foods, beverages, or other drugs. A popular example of drug-food interaction is the effect of grapefruit in the metabolism of drugs.
Diabetic hypoglycemia is a low blood glucose level occurring in a person with diabetes mellitus. It is one of the most common types of hypoglycemia seen in emergency departments and hospitals. According to the National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP), and based on a sample examined between 2004 and 2005, an estimated 55,819 cases involved insulin, and severe hypoglycemia is likely the single most common event.
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 cranberry, cranberry powder, and dietary supplements containing cranberry extracts.
Dextromethorphan (DXM) is a cough suppressant in over-the-counter cold and cough medicines. It affects NMDA, and sigma-1 receptors in the brain, all of which have been implicated in the pathophysiology of depression. In 2022, the FDA approved a formulation of it combined with bupropion named Auvelity to serve as a rapid acting antidepressant in patients with major depressive disorder.
Naringin is a flavanone-7-O-glycoside between the flavanone naringenin and the disaccharide neohesperidose. The flavonoid naringin occurs naturally in citrus fruits, especially in grapefruit, where naringin is responsible for the fruit's bitter taste. In commercial grapefruit juice production, the enzyme naringinase can be used to remove the bitterness created by naringin. In humans naringin is metabolized to the aglycone naringenin by naringinase present in the gut.
Grapefruit seed extract (GSE), also known as citrus seed extract, is a liquid extract derived from the seeds, pulp, and white membranes of grapefruit. GSE is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin. Commercially available GSEs sold to consumers are made from the seed, pulp, and glycerin blended together. GSE is sold as a dietary supplement and is used in cosmetics.
Zygosaccharomyces bailii is a species in the genus Zygosaccharomyces. It was initially described as Saccharomyces bailii by Lindner in 1895, but in 1983 it was reclassified as Zygosaccharomyces bailii in the work by Barnett et al.
Some fruit juices and fruits can interact with numerous drugs, in many cases causing adverse effects. The effect is most studied with grapefruit and grapefruit juice, but similar effects have been observed with certain other citrus fruits.
Apple cider vinegar, or cider vinegar, is a vinegar made from fermented apple juice, and used in salad dressings, marinades, vinaigrettes, food preservatives, and chutneys. It is made by crushing apples, then squeezing out the juice. Bacteria and yeast are added to the liquid to start the alcoholic fermentation process, which converts the sugars to alcohol. In a second fermentation step, the alcohol is converted into vinegar by acetic acid-forming bacteria. Acetic acid and malic acid combine to give vinegar its sour taste.
Synergistic enhancers of antiretrovirals usually do not possess any antiretroviral properties alone, but when they are taken concurrently with antiretroviral drugs they enhance the effect of that drug.
The erythromycin breath test (ERMBT) is a method used to measure metabolism (oxidation and elimination from the system) by a part of the cytochrome P450 system. Erythromycin produces 14CO2, and this 14CO2 can be measured to study drugs that interact with the cytochrome P450 system. Erythromycin is tagged with carbon-14 and given as an intravenous injection; after 20 minutes the subject blows up a balloon and the carbon dioxide exhaled that is tagged with carbon-14 shows the activity of the CYP3A4 isoenzyme on the erythromycin. ERMBT can be used to determine how drugs that the CYP3A4 isoenzyme metabolizes will function in a given individual.
Intravenous sugar solution, also known as dextrose solution, is a mixture of dextrose (glucose) and water. It is used to treat low blood sugar or water loss without electrolyte loss. Water loss without electrolyte loss may occur in fever, hyperthyroidism, high blood calcium, or diabetes insipidus. It is also used in the treatment of high blood potassium, diabetic ketoacidosis, and as part of parenteral nutrition. It is given by injection into a vein.