Peter Lio, M.D., is assistant professor of clinical dermatology and pediatrics at Northwestern University’s Feinberg School of Medicine, and private practice, Dermatology and Aesthetics of Wicker Park, Wicker Park, Chicago.
There seems to be renewed interest in coconut and other natural oils, with topics as far-flung as using coconut oil as a sunscreen (spoiler: it didn’t work very well!) Here, we’ll tell you where it does show promise.
From the earliest recorded histories, botanical oils have been used as topical treatments for the skin.1 The coconut tree (Cocos nucifera), a member of the palm family, is largely cultivated for its nutritional, cosmetic, and medicinal values, while its oil, derived from the coconut fruit, has long been recognized to be beneficial to the skin.2 Indeed, many cultures have ancient traditions utilizing it for medicinal preparations.3
While the number of high-quality clinical studies on topically applied coconut oil is low, some compelling evidence is available. Notably, there seems to be renewed interest in coconut and other natural oils, with topics as far-flung as using coconut oil as a sunscreen (spoiler: it didn’t work very well!).4
Many studies specifically use virgin coconut oil (VCO). VCO is generally defined as coconut oil being obtained through mechanical or natural means, which do not lead to alteration of the oil, and where the oil has not undergone chemical refining, bleaching or deodorizing. This is in contrast to methods that use undesirable solvents such as hexane to extract the oil.5
Coconut oil is relatively high in medium-chain fatty acids, making it somewhat unique and granting it properties that may be useful in the treatment of a number of conditions including obesity, dyslipidemia, diabetes and hypertension.2
More relevant to the skin, however, it has been shown to be a capable moisturizer. A randomized double-blind study pitted virgin coconut oil against mineral oil in 34 patients with mild-to-moderate xerosis. In the perhaps surprising conclusion, coconut oil was found to be equal to (with a trend toward being superior to) mineral oil as an emollient, resulting in significant skin hydration and increased surface lipid levels, with equal safety.6
Supporting these data, and similar to the findings with sunflower seed oil, VCO has been shown to improve barrier function in low-birth-weight babies.7, 8 There is a strong suggestion that by strengthening the skin barrier in these at-risk infants, morbidity and mortality due to sepsis can be reduced.
Coconut oil has also been shown to possess another important property relevant to dermatology: It can decrease staphylococcal colonization on the skin. In a randomized controlled trial, coconut oil was found to clear an impressive 95% of staphyoloccal colonization in patients with atopic dermatitis (AD).9 This is extremely provocative in a time when we are all increasingly concerned about the role of bacteria in AD10, and simultaneously worried about increasing bacterial resistance.11 A safe and inexpensive agent for decolonizing the skin could be of tremendous clinical benefit and this line must continue to be researched.
ASLO READ: Skin barrier benefits of sunflower seed oils
The barrier repair and antibacterial properties of coconut oil seem to pan out when put to a more clinical test. In a randomized trial of 117 patients with AD, mean SCORAD decreased by 68.23% in the VCO group compared to only 38.13% in the mineral oil group (P < 0.001) at 8 weeks.12 There is no doubt that further studies are warranted in AD to best determine a role for coconut oil.
Like many other botanicals, however, coconut oil is not without some downsides. Specifically, there are a number of coconut-derived compounds present in cosmetics, some of which are not infrequent causes of allergic contact dermatitis. Cocamidopropyl betaine (CAPB) is a widely used surfactant that debuted in 1976 as the “No More Tears” ingredient in children’s shampoos [Jacob 2008]. However, it has the dubious distinction of being the North American Contact Dermatitis Group’s allergen of the year for 2004, and is thought to have a contact sensitization prevalence is estimated at between 3.0 and 7.2%.13
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Counseling for patients with known allergy to CAPB can be challenging because the cross-reactivity of CAPB with other coconut-derived surfactants and coconut oil itself is largely unknown. One randomized study of 12 patients with known CAPB allergy and 10 control patients examined 11 coconut-derived surfactants, as well as coconut oil cross-reactivity. Remarkably, not a single patient in the study reacted to coconut oil, and only three of the 12 patients with previous reactions to CAPB reacted on retesting. All of these reactions were doubtful. This study suggested that reactions to CAPB may represent irritant dermatitis as opposed to true allergic reactions, and that the risk of reacting to coconut oil itself is likely very low.14
Coconut oil has already proven itself useful and important in dermatology with a long history of use dating back to ancient times, to widespread use as a raw material for cosmetic derivatives. With powerful emollient properties and exciting antibacterial effects, this natural oil will likely continue to captivate researchers and clinicians alike. Coconut oil may serve us in as yet unimagined ways.
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Finally, despite the insistence of the famous song by Harry Nilsson, it is most certainly not recommended that one “put the lime in the coconut” before applying it to the skin; such recklessness could very likely result in a severe case of phytophotodermatitis!
1 Danby SG, AlEnezi T, Sultan A, Lavender T, Chittock J, Brown K, Cork MJ. Effect of olive and sunflower seed oil on the adult skin barrier: implications for neonatal skin care. Pediatr Dermatol. 2013 Jan-Feb;30(1):42-50. doi: 10.1111/j.1525-1470.2012.01865.x.
2 Fernando WM, Martins IJ, Goozee KG, Brennan CS, Jayasena V, Martins RN. The role of dietary coconut for the prevention and treatment of Alzheimer's disease: potential mechanisms of action. Br J Nutr. 2015 Jul 14;114(1):1-14.
3 Debmandal M, Mandal S. Coconut (Cocos nucifera L.: Arecaceae): in health promotion and disease prevention. Asian Pac J Trop Med. 2011;4(3):241-7.
4 Gause S, Chauhan A. UV blocking potential of oils and juices. Int J Cosmet Sci. 2015 Nov 27.
5 APCC Standards for Virgin Coconut Oil. Jakarta, Indonesia: Asian and Pacific Coconut Community. http://www.apccsec.org/document/VCO-STANDARDS.pdf Accessed on 12/1/2015.
6 Agero AL, Verallo-Rowell VM. A randomized double-blind controlled trial comparing extra virgin coconut oil with mineral oil as a moisturizer for mild to moderate xerosis. Dermatitis. 2004 Sep;15(3):109-16.
7 Nangia S, Paul V, Chawla D, et al. Topical coconut oil application reduces transepidermal loss in preterm very low birth weight neonates: a randomized clinical trial. Pediatrics 2008; 121: S139.
8 Nangia S, Paul VK, Deorari AK, Sreenivas V, Agarwal R, Chawla D.Topical Oil Application and Trans-Epidermal Water Loss in Preterm Very Low Birth Weight Infants-A Randomized Trial. J Trop Pediatr. 2015 Dec;61(6):414-20.
9 Verallo-Rowell VM, Dillague KM, Syah-Tjundawan BS. Novel antibacterial and emollient effects of coconut and virgin olive oils in adult atopic dermatitis. Dermatitis. 2008 Nov-Dec;19(6):308-15.
10 Brüssow H. Turning the inside out: The microbiology of atopic dermatitis. Environ Microbiol. 2015 Sep 16.
11 Demos M, McLeod MP, Nouri K. Recurrent furunculosis: a review of the literature. Br J Dermatol. 2012 Oct;167(4):725-32.
12 Evangelista MT, Abad-Casintahan F, Lopez-Villafuerte L. The effect of topical virgin coconut oil on SCORAD index, transepidermal water loss, and skin capacitance in mild to moderate pediatric atopic dermatitis: a randomized, double-blind, clinical trial. Int J Dermatol. 2014 Jan;53(1):100-8. doi: 10.1111/ijd.12339.
13 Jacob SE, Amini S. Cocamidopropyl betaine. Dermatitis. 2008 May-Jun;19(3):157-60.
14 Shaffer KK, Jaimes JP, Hordinsky MK, Zielke GR, Warshaw EM. Allergenicity and cross-reactivity of coconut oil derivatives: A double-blind randomized controlled pilot study. Dermatitis. 2006 Jun;17(2):71-6.