Grapefruit

    Written by:
    Katie Jantz

    Fact-checked

    by:

    Nick Milazzo
    Last Updated: July 3, 2024

    Grapefruit is a citrus fruit rich in bioactive phytochemicals. It has been linked to small reductions in body weight, cholesterol, and blood pressure in preliminary studies. Importantly, grapefruit interacts with many commonly used medications and could have detrimental outcomes when combined.

    81 references on this page
    495 participants in 6 trials and 1 meta-analysis

    Overview

    Dosage information

    Dosage Information

    Grapefruit is usually taken as whole fresh grapefruit, 100% grapefruit juice, freeze-dried whole grapefruit powder, or grapefruit seed extract.

    When fresh grapefruit, grapefruit juice, and freeze-dried grapefruit capsules were directly compared in one study, fresh grapefruit seemed the most promising for various cardiometabolic outcomes. However, the only effect that reached statistical significance was weight loss.[4]

    Most studies have provided one-half of a fresh grapefruit or an 8-oz glass of grapefruit juice three times a day before meals. When it was reported, the daily dose of naringenin (the major flavonoid in grapefruit) has ranged from 81 to 142 mg daily.[5][6]

    For regular dietary intake, the US Dietary Guidelines suggest consuming whole fruit over juice, but either one can help you meet the recommended 2 cups of fruit per day.

    Examine Database: Grapefruit

    Frequently asked questions

    Update History

    Examine Database References

    1. Weight - Fujioka K, Greenway F, Sheard J, Ying YThe effects of grapefruit on weight and insulin resistance: relationship to the metabolic syndromeJ Med Food.(2006 Spring)
    2. Weight - Dallas C, Gerbi A, Tenca G, Juchaux F, Bernard FXLipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (SINETROL) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-phosphodiesterase (PDE)Phytomedicine.(2008 Oct)
    3. Weight - Caitlin A Dow, Scott B Going, Hsiao-Hui S Chow, Bhimanagouda S Patil, Cynthia A ThomsonThe effects of daily consumption of grapefruit on body weight, lipids, and blood pressure in healthy, overweight adultsMetabolism.(2012 Jul)
    4. Total cholesterol - Cerda JJ, Robbins FL, Burgin CW, Baumgartner TG, Rice RWThe effects of grapefruit pectin on patients at risk for coronary heart disease without altering diet or lifestyleClin Cardiol.(1988 Sep)
    5. Blood Flow - Keevil JG, Osman HE, Reed JD, Folts JDGrape juice, but not orange juice or grapefruit juice, inhibits human platelet aggregationJ Nutr.(2000 Jan)
    6. QTc Intervals - Chorin E, Hochstadt A, Granot Y, Khoury S, Schwartz AL, Margolis G, Barashi R, Viskin D, Ghantous E, Schnapper M, Mekori T, Fourey D, Guevara-Valdivia ME, Marquez MF, Zeltzer D, Rosso R, Viskin SGrapefruit juice prolongs the QT interval of healthy volunteers and patients with long QT syndrome.Heart Rhythm.(2019 Aug)
    7. Weight - Onakpoya I, O'Sullivan J, Heneghan C, Thompson MThe effect of grapefruits (Citrus paradisi) on body weight and cardiovascular risk factors: A systematic review and meta-analysis of randomized clinical trials.Crit Rev Food Sci Nutr.(2017 Feb 11)