Ode to the Grapefruit
It’s probably one of the most famous fruits that is known for its ability to make the breakfast bowl a healthy place. The grapefruit, enjoyed (or tolerated) by many health-seeking men and women for many years, for many very good reasons.
This citrus delight is loaded with vitamin C and vitamin A (carotenoid form), is a good source of pantothenic acid, copper, potassium, biotin, and vitamin B1, is high in antioxidants, contains fiber, and is power-packed with phytonutrients (including liminoids and lycopene).
Grapefruit comes with an array of health benefits including some evidence for lowering LDL cholesterol, prevention of cancer and kidney stones, DNA repair and more!
Yet production and price for our beloved morning companion is down! Why?
The Not So Sunny Side of This Citrus Fruit – From Ode to Scold
It could be that the popularity of this “morning fruit” is dwindling because word got out about its “dark side.” Recently, it has been discovered that the fruit and its juice contains a chemical (furanocoumarins) known to interact with many medications. As a result, dangerously high levels of some drugs ensue when an unknowing, newly crowned, health enthusiast slugs down a glass of grapefruit juice with the usual morning chemical cocktail.
In fact, a 2012 review of the Canadian pharmaceutical market estimated more than 85 drugs can potentially interact with compounds found in the whole fruit, juice, or concentrate and 43 could cause serious consequences. Furthermore, one health expert who was interviewed on the study’s results told CBS that drinking one glass of grapefruit juice with one statin pill is similar in potency to taking twenty pills!
Even creepier, the effects of the grapefruit juice seem to increase over time with some meds. This means, you could have sipped on grapefruit juice in the morning and its kryptonite power continues to grow and to have an additive adverse effect on some medication as the time clicks away.
Doubly not good.
Some key points of this landmark “Forbidden Fruit” study include:
- Drugs that interact with grapefruit have all of the following characteristics: they are administered orally, they have very low to intermediate absolute bioavailability, and they are metabolized by the cytochrome P450 3A4 enzyme (CYP3A4).
- All sources of grapefruit and certain related citrus fruits can irreversibly inhibit CYP3A4 in the gastrointestinal tract; to prevent this interaction, affected drugs should not be consumed with any of these fruits during the treatment period, or noninteracting alternative medications should be prescribed.
- Older patients have the greatest possibility of ingesting grapefruit and interacting medications and are the most vulnerable to the adverse clinical consequences.
You can download this article here.
I advise anyone on medication does this.
Starting on page 4, it lists the drugs that can interact with grapefruit fruit, juice, and concentrate.
For the really geeky, if you’ve done a SNP test to determine your CYP3A4 genetic profile, you can also determine how vulnerable you are to this interaction.
Grapefruit Oil- Alas, An Oil of Any Other Name- No More Guilt By Association!!!
In 2015, I wrote a blog on potential essential oils-drug interactions. I updated it in May of 2016 and highlighted the citrus oils due to grapefruit’s tainted namesake.
The bottom line is that the essential oils contain different molecules than the juice, concentrate, and whole fruit. Specifically, citrus oils predominant in the volatile constituents and only contain a slight amount of the non-volatile compounds, such as the furanocoumarins.
Here’s my excerpt on grapefruit (get the full article with references here):
The Grapefruit Oil Controversy: To Be or Not to Be (Bergamottin or DHB)
Grapefruit juice (GFJ) can be a major inhibitor of drugs due to the presence of furanocoumarins. Human studies suggest that bergamottin and 6,7-dihydroxybergamottin (DHB), are the primarily furanocoumarins responsible for drug interactions with grapefruit juice. (2)
According to the essential oil pharmacist, “While bergamattin and bergapten are found in grapefruit oil and other citrus oils, the likelihood of them causing clinically important drug interactions is much lower than with DHB or flavonoids.” (3)
I think it’s important to point out that citrus essential oils, though pressed from the peel, have volatile constituents that predominate and tend to balance the non-volatile constituents. For example, in simple terms, Mr. Wiki states, “A clear liquid (sometimes there is a deposit consisting of waxes) in color from green to greenish yellow, bergamot essential oil consists for the most part (average 95%) of a volatile fraction and for the remaining (5%) of a non-volatile fraction (or residual). Chemically it is a highly complex mixture of many classes of organic substances, particularly for the volatile fraction terpenes, esters, alcohols and aldehydes, and for the non-volatile fraction, oxygenated heterocyclic compounds as coumarins and furanocoumarins.”
For me, if there is a potential interaction with some of the constituents present in the oil, I’d suggest using a different citrus oil if one is on blood pressure medications or other medications that can interact with the liver enzymatic pathway that furanocoumarins modulate, though the levels are very, very low. Your doctor can help reference which medications these are.
There are some studies that show an effect with these JUICES. Grapefruit juice and grapefruit have the additional evidence of inhibiting intestinal P-glycoprotein, which further rises the drug levels in some people, earning its reputation for more cautious imbibing in medication users. (Again, please note these are the nonvolatile fractions, as stated above.)
Recently, I also found additional evidence of the differences between the citrus fruits and the oils. One of the most renowned aromatherapist, Robert Tisserand and his coauthor, Rodney Young wrote in their book, Essential Oil Safety: A Guide for Health Care Professionals that, “it is not likely to cause drug interactions” based on the concentrations of bergomottin and bergapten. These are two other furanocoumarins with lesser effects on CYP34A.
In fact, several studies and most aromatherapists will tell you the predominant constituent found in a quality grapefruit oil is limonene, which is a power-packed monoterpene with a whole array of health benefits. A 2014 analysis of five citrus species reported in the Journal of Agricultural Science (bold emphasis mine):
All over the world Citrus is one of the widespread genus due to its prominent production. Citrus essential oils are naturally occurring, volatile and odoriferous oils synthesized by non woody parts of aromatic plants such as seeds, buds, leaves, flowers, stems, fruits, twigs and roots etc. and accumulated in secretory or epidermis cells and also sometimes in cavities (Ahmad, 2006). Essential oil from Citrus fruit peel is the fundamental product of genus Citrus and typically isolated by distillation or solvent extraction (Mondello et al., 2005). These are the complex mixtures of about 400 compounds of which 1-15% are non-volatile whereas 85-99% is the volatile constituents (Nannapaneni et al., 2009). Other organic compounds present in Citrus essential oils are aliphatic hydrocarbons, alcohols (linalool), aldehydes (citral), acids, esters and some aromatic compounds (Sharma & Tripathi, 2006). Svoboda & Greenaway (2003) reported the chief chemical constituent of Citrus essential oils is limonene and have a range of 32 to 98%.
Another study in International Journal of Food Science & Technology analyzed grapefruit and concluded (bold emphasis mine):
The chemical composition of the essential oil (EO) obtained by solvent-free microwave extraction (SFME) and hydrodistillation (HD) from the peel of grapefruit (Citrus Paradisi. L) was analysed by gas chromatography/mass spectrometry (GC/MS). Totally, twenty-five components were identified in the EO. Limonene was observed as dominant (91.5–88.6%) for two extraction methods, SFME and HD, respectively. ?-Pinene (0.8–1.2%), linalool (1.1–0.7%), ?-terpinene (0.7–1.0%) and the other minor components were also detected. Disc diffusion method was applied to determine the antibacterial properties of the EO. The results showed that the EO of grapefruit peel had a wide spectrum of antimicrobial activities against Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Escherichia coli, Salmonella typhimurium, Serratia marcescens and Proteus vulgaris, with their inhibition zones ranging from 11 to 53 mm.
The American Journal of Plant Science states that these compounds that are present have beneficial health effects (I am the one bolding things again):
There are several reports on the essential oil composition of citrus peels, some of which includes; D-limonene, ?-Myrcene, ?-pinene, ?-pinene, ?-terpinene, ?-terpinolene, ?-Caryophyllene, copaene, ?-phellandrene etc. [5,11-14]. Citrus fruits peels are also known to contain some antioxidants; flavonoids such as hesperidine, narirutin, naringin and eriocitrin, and also polyphenols such as caffeic acid, p-coumaric acid, ferulic acid and sinapinic acid [8,15-17]. The antimicrobial roles of flavonoids are well documented .
The article also expresses the importance of climate and cultivation in relationship to variation of constituents found in the oil. This is where quality is essential!
Bottom Line (Or Drop)
Grapefruit essential oil is very different than the whole fruit, juice or concentrate. It is unlikely to cause an interaction with medication.
However, err on the side of caution and use this article to cross-reference an unlikely potential reaction with the oil and to determine if you should be eating or drinking the fruit.
Three Reasons Why We Can Groove on Grapefruit Oil
There are so many uses for this citrus oil. I will highlight an overview from the Journal of Agricultural Science, then click here to read “Three Reasons to Groove on Grapefruit Oil for a Fitter and More Fabulous New Year.”
Citrus essential oils act as natural antioxidants because flavanone glycosides namely naringin, narirutin, hesperidin and neohesperidin are valuable phenolic compounds found in Citruspeel oil which make them liable to avert rancidity of food (Anagnostopoulou et al., 2006). Essential oils of Citrus peels are medicinally very important and show variety of biological effects because they are rich in flavonoids (flavone, flavonol and flavanone), terpenes, carotenes and coumarines which are responsible for antimicrobial activity (Tepe et al., 2005). Consequently Citrus essential oils are extensively used in pharmaceutics as an antimicrobial, anti-diabetic, antioxidant, insect repellent, carminative, larvicidal, antiviral, antihepatotoxic and antimutagenic agent (Kanaze et al., 2008).
Safe Use of Grapefruit Oil
Never overuse an essential oil. They are powerful. 1-2 drops are enough. You can drink therapeutic grapefruit oil in your water or rub it on your body. Avoid the sun following application, as the oil is photosensitive.
Please see my database for additional articles on essential oil safety and proper use.
Click here for a video on grapefruit oil and interactions.
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This material is for information purposes only and is not intended to diagnose, treat, or prescribe for any illness. You should check with your doctor regarding implementing any new strategies into your wellness regime. These statements have not been evaluated by the FDA.
Grapefruit. World’s Healthiest Foods. http://www.whfoods.com/genpage.php?tname=foodspice&dbid=25
United States Department of Agriculture. National Agriculture Statistics Service. 2014-2015 Service Summary. 2014-2015 Citrus Summary. https://www.nass.usda.gov/Statistics_by_State/Florida/Publications/Citrus/Citrus_Summary/Citrus_Summary_Prelim/cit91715.pdf
Bailey DG, Dresser G, Arnold MO. Grapefruit–medication interactions: Forbidden fruit or avoidable consequences? CMAJ. November 26, 2012; cmaj.120951. http://www.cmaj.ca/content/early/2012/11/26/cmaj.120951
Robert Tisserand, Rodney Young. Essential Oil Safety: A Guide for Health Care Professionals. Elsevier Health Sciences. Dec 2, 2013. Page 298.
Uysal B, Sozmen B, Tktas F, Oksal BS, Kose EO. Essential oil composition and antibacterial activity of the grapefruit (Citrus Paradisi. L) peel essential oils obtained by solvent-free microwave extraction: comparison with hydrodistillation. International Journal of Food Science & Technology. 2011; 46: 1455–1461. doi: 10.1111/j.1365-2621.2011.02640.x
Okunowo , Oyedji O, Afolabi L, Matanami E. Essential Oil of Grape Fruit (Citrus paradisi) Peels and Its Antimicrobial Activities. American Journal of Plant Sciences. 2013; 4(7B): 1-9. doi: 10.4236/ajps.2013.47A2001.
Genetic variability to essential oil composition in four citrus fruit species. Pakistan Journal of Botany. January 2006; 38(2):319-324 · January 2006. http://www.pakbs.org/pjbot/PDFs/38(2)/PJB38(2)319.pdf
Javad S, Javaid A, Nawaz S, Saeed MK, Mahmood Z, Siddiqui SZ, Ahmad R. Phytochemistry, GC-MS Analysis, Antioxidant and Antimicrobial Potential of Essential Oil From Five Citrus Species. Journal of Agricultural Science. 2014. 6(3). http://www.ccsenet.org/journal/index.php/jas/article/viewFile/31947/19600