Tropical oils, namely palm oil and coconut oil, are widely used in tropical countries for a variety of purposes ranging from cooking to grooming. Although the oils are commonly found in beauty care products (eg, shampoos, conditioners, lotions), they are seen less often in American diets. 1
Palm Oil
Palm oil is the second most consumed vegetable oil in the world. It comes from the tropical plant, Elaeis guineensis . Palm oil is made up of roughly 50% saturated fat, with the ratio of saturated to unsaturated fat being nearly equal. Palm oil is rich in antioxidants, such as vitamin E and beta-carotene . 2,3
Coconut Oil
Coconut oil is made up of more than 90% saturated fats. Most of the saturated fats are medium-chain fatty acids (MCFA), which tend to be quickly used by the body to produce energy, rather than accumulating in fat tissue. Some researchers feel that because of its structure, the saturated fat found in coconut oil is not as damaging as other saturated fats, like those found in animal products. 13
Sources
Tropical oils may be found in ingredients of various processed foods, such as candy and baked goods. The oils may also be found in their pure or processed liquid forms and as ingredients in skin and hair care products.
What Is the Scientific Evidence for Tropical Oils?
Palm Oil
Tropical oils, like palm oil, have been perceived as unhealthy since they may pose a risk of cardiovascular problems. Palm oil has been known to raise cholesterol levels in people who already have high cholesterol . However, the effect of palm oil on cholesterol levels is apparently not so simple. 5 Consuming fresh palm oil may lower the amount of cholesterol made naturally by the body more than other oils, and there is evidence to suggest that palm oil may actually reduce the risk of heart attack and similar cardiovascular events, as well as high blood pressure . 2,3,5,7,12
Palm oil’s bad reputation may be due to its unhealthy effects after processing. Palm oil used for cooking is usually processed to an oxidized state. Unlike fresh palm oil, the oxidized version may increase the risk of harm to the liver, lungs, kidneys, reproductive organs, and heart. 2,3
Some researchers have suggested that palm oil (particularly a version called red or refined palm oil) may protect against certain cancers and vitamin A deficiency due to its high beta-carotene content. 2,3,4,5,8,9,10,12 However, the evidence is not solid enough to recommend red palm oil for individuals at risk for these conditions.
Coconut Oil
Coconut oil had been dismissed as unhealthy because of its high saturated fat levels. However, a better understanding of MCFA and preliminary research has suggested that the oil may actually have some health benefits. In studies of 2 populations that frequently use coconut oil, researchers found that although the population had higher overall cholesterol levels there was no increased risk of cardiovascular disease21,22. Three small randomized trials and two observational trials found that the use of coconut oil may be associated with improvements in waist circumference and increased HDL levels23, 24, 25, 26,27. However, these trials were small and some were preliminary. A larger randomized trial found that coconut oil had similar effects on lipid profile as sunflower oil28. In addition, a systematic review that included 8 randomized control trials and 13 observational trials found that those using unsaturated fatty acids, like olive oil, as main cooking oil had better lipid profile than those that used coconut oil29. A small randomized control trial also found no benefit in lipid profiles or satiety in children30.
For now, the conclusion is that there is no clear answer on benefits or harms of coconut oil. More research needs to be done to learn the effects of coconut oil and compare it to other fats that are currently considered healthy options. It is important to note that studies relied on virgin coconut oil not processed coconut oil.
Topical application has been shown to improve skin and hair conditions. A small, randomized, double-blind controlled trial of 34 patients with xerosis (a skin condition in which the skin is dry, rough, and itchy) found that virgin coconut oil is as effective and safe as mineral oil for moisturizing the skin of adults with mild to moderate xerosis. 15
Another small, double-blind, controlled trial found virgin coconut oil to effectively treat atopic dermatitis (a chronic inflammation of the skin) in adults. 19
A commercially available repellant containing coconut oil and jojoba (a waxy seed commonly used in cosmetics) is reported to be effective in keeping away mites that cause scabies, an infestation of these small insects in the skin. 20
Coconut oil has also been shown to prevent hair damage due to combing compared to other oils, such as mineral and sunflower oils. Researchers believe that its relative high affinity for hair protein and ability to penetrate deep into the hair shaft accounts for coconut oil’s superior performance. 16
A study also showed that coconut oil may benefit preterm babies as well. Preterm babies given a coconut oil massage had faster weight gain and growth compared to those given mineral oil massage. 14
Safety Issues
Although tropical oils are generally well-tolerated, some individuals may experience abdominal discomfort or bloating after consuming them. Other than local irritation, their topical application is also considered generally safe.
References
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REF11 11. Canfield LM, Kaminsky RG, Taren DL, Shaw E, Sander JK. Red palm oil in the maternal diet increases provitamin A carotenoids in breastmilk and serum of the mother-infant dyad. Eur J Nutr . 2001 Feb;40(1):30-38.
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REF13 13. Amarasiri WA, Dissanayake AS. Coconut fats. Ceylon Med J . 2006 Jun;51(2):47-51.
REF14 14. Sankaranarayanan K, Mondkar JA, Chauhan MM, Mascarenhas BM, Mainkar AR, Salvi RY. Oil massage in neonates: an open randomized controlled study of coconut versus mineral oil. Indian Pediatr . 2005 Sep;42(9):877-884.
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REF20 20. Jörg Heukelbach, Hermann Feldmeier. Scabies. Lancet . 2006; 367: 1767–1774.
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REF27 Harris M, Hutchins A, Fryda L.The Impact of Virgin Coconut Oil and High-Oleic Safflower Oil on Body Composition, Lipids, and Inflammatory Markers in Postmenopausal Women. J Med Food. 2017 Apr;20(4):345.
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