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The Grapefruit: A Deeper Look

Grapefruits are the beauties of the winter season. The fruit bins, at some of our favorite produce markets, are stacked with the bright white, yellow, pink and deep red colors of grapefruits. Being of different colors and having different tastes ranging from acidic to sweet, grapefruits  have a variety of health benefits (and risks!).


Good for the body, but….

These bulbous sized fruits, within a healthy overall diet, help cut back on obesity, diabetes, and heart disease as well as promote healthy complexion and overall good health [i]. Grapefruits are rich sources of vitamin C, fiber, water and lycopene, a powerful antioxidant contained in the red and pink hues [ii].  Nutritional goodness from the grapefruit helps to maintain strong immune systems, decreases bad cholesterol, and promotes a healthy digestive tract.  The abundance of lycopene has also been associated in the prevention of prostate cancer along with vitamin C [i] [iii]. Additionally, grapefruits are also good sources of potassium.  Potassium, lycopene, vitamin C and choline are also involved in promoting a healthy heart [i].  But in some cases, grapefruits should be avoided.


Take caution in certain circumstances

Under certain treatment regimens for cancer, grapefruits should not be consumed.  Under normal circumstances, the intestines contain an enzyme that help to metabolize medications to prevent overdose.  Grapefruits contain a chemical called furanocoumarin, which can inhibit the normal intestinal enzyme resulting in high levels of certain medications in the blood stream, potentially causing dangerous side effects [iv][v]. Currently, grapefruits have been known to interact with more than 85 drugs and the list includes statins which lower cholesterol, some antibiotics, and some cancer and heart drugs [vi].  Tangelos and seville oranges should also be eliminated from the diet because they also contain furanocoumarin.


During cancer treatment

During cancer treatment, grapefruit juice can increase the availability to the body of various drugs (anti- inflammatory and immunosuppressive agents) by inhibiting intestinal enzymes, potentially resulting in fatal side effects.5 Interestingly, researchers have found that these food and drug interactions mainly occur with drugs taken orally.  The degree of the effect can vary from person to person, depending on the medications that they currently take [v]. To note, it has also been found that this interaction can happen even if the fruit is consumed hours after taking the medication.  However, care should be taken to never stop taking the medication prescription without talking with your doctor first [v].



For those on medications for cancer treatment, take caution with grapefruit.  The nutrients provided can be found in other fruits and veggies like tomatoes, leafy greens, eggs, and avocados.  If the taste is something hard to live without, substitutions that satisfy the craving may help.  Other citrus fruits like oranges can help, as well as peaches, starfruit, or nectarines.  For additional recommendation, consult a registered dietitian to go over ways to satisfy your cravings for grapefruits, and exactly which medications are contraindicated.


[i] LD, M., & Natalie Olsen, A. (2018). Grapefruit: Health benefits, facts, and research. Medical News Today. Retrieved 8 January 2018, from https://www.medicalnewstoday.com/articles/280882.php
[ii] Grapefruit. (2018). Whfoods.com. Retrieved 8 January 2018, from http://www.whfoods.com/genpage.php?tname=foodspice&dbid=25
[iii] Graff, R., Pettersson, A., Lis, R., et al. (2016). Dietary lycopene intake and risk of prostate cancer defined by ERG protein expression. American Journal Of Clinical Nutrition, 103(3), 851-860. http://dx.doi.org/10.3945/ajcn.115.118703
[iv] Grapefruit and medication: a cautionary note. 2016. Harvard Health Publishing @ Harvard Medical School.  Accessed at: https://www.health.harvard.edu/family-health-guide/grapefruit-and-medication-a-cautionary-note
[v] Gardner, A. (2018). 21 Things You Should Know About Grapefruit. Health.com. Retrieved 8 January 2018, from http://www.health.com/food/grapefruit-facts#grapefruit-intro
[vi] Scripture, C., & Figg, W. (2018). Drug Interactions in Cancer Therapy. Medscape. Retrieved 8 January 2018, from https://www.medscape.com/viewarticle/540883_2
Jessica Iannotta, MS, RD, CSO, CDN

Jessica is a registered dietitian and certified specialist in oncology nutrition (CSO). She studied nutrition at Cornell University and completed her dietetic internship at New York Presbyterian Weill Cornell Medical Center. She obtained her Master's degree through the University of Medicine and Dentistry of New Jersey. Jessica has worked in inpatient and outpatient oncology settings since 2001 in the North Shore-LIJ Health System. Jessica is in charge of all operations including clinical and culinary operations ranging from menu development to evidence-based website content, relationships with registered dietitians and social workers and developing processes and protocols for intake, management and outcomes analysis of patients.

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