For many years, coconut oil was labeled as dangerous due to its high saturated fat content. However, now that people are coming to realize that saturated fat is not inherently bad, the health benefits of coconut oil are being re-examined. So far, the effects on inflammation, metabolism, and skin health are promising but require further investigation.
In this article, we explore the potential health benefits of coconut oil for the body, skin & hair and its controversial effects on heart health.
What is Coconut Oil?
Coconut Oil is the oil extracted from the “meat” inside the hard-shelled coconut (Cocos nucifera). Coconut oil is solid at room temperature and has a very long shelf life (six months at 75 °F) [1].
The majority of coconut oil (approx 65%) is composed of medium-chain triglycerides (MCTs), which are triglycerides and fatty acids with a carbon length chain of 6 – 12. MCTs are mostly comprised of lauric acid, which has a 12 carbon chain and therefore is almost considered a long-chain fatty acid.
Coconut oil is produced mostly in Asian countries and is widely used in the food and cosmetic industries [1].
Health Benefits of Coconut Oil
1) Metabolism
MCTs from coconut oil are “thermogenic”; this means that consuming coconut oil may actually increase energy expenditure (fat burning), versus consuming the same amount of calories from other fats [2].
Coconut oil is 65% MCTs. A number of studies have explored fat loss and metabolic changes in response to MCT oil. In every one of these studies, MCT oil was found to increase metabolism and fat loss, compared to other fat sources [3, 4, 2, 5].
Similarly, another study found that after 7 days, individuals on a diet rich in MCTs from coconut oil and butter burned more fat and had a significantly higher resting metabolic rates than those consuming diets rich in beef tallow [6].
Subjects (n=20) who consumed 30ml of coconut oil per day lost an average of 1.1 inches from their waist circumference, but this effect was observed only in men [7].
In 40 women, consumption of coconut oil led to a greater decrease in waist circumference, compared with soybean oil [8].
It’s important to note that adding coconut oil on top of daily food intake instead of replacing another (saturated) fat source would likely have opposite effects on metabolism and weight control.
2) Inflammation
Women who consumed a high-fat diet based on coconut oil had less post-meal inflammation, especially when compared to the group on a diet high in unsaturated fatty acids [9].
Virgin coconut oil was found to be anti-inflammatory for artificially-induced ear and paw swelling in rats, as well as ulcerative colitis [10].
In a mouse study, the anti-inflammatory activity of virgin coconut oil was comparable to aspirin [11].
3) Antimicrobial
Lauric acid makes up almost 50% of coconut oil. After being digested, coconut oil also forms the monoglyceride, monolaurin. Both lauric acid and monolaurin kill pathogenic bacteria, viruses and fungi e.g. Staphylococcus Aureus [12, 13].
In test tubes, coconut oil was effective at killing various forms of Candida, especially Candida Albicans [14].
Coconut oil is an effective treatment for vaginal thrush (yeast infection) [15].
One way coconut oil kills candida is by disrupting the yeast’s plasma membranes [16].
Many disease-causing microbes, including potentially deadly ones like HIV and drug-resistant bacteria, are vulnerable to MCTs found in coconut oil [12].
When used topically, coconut oil showed potential in dealing with local bacterial infections [17].
Coconut oil is effective at reducing the levels of dangerous bacteria found in poultry [18].
MCTs found in coconut oil have also been shown to reduce the growth of certain species of Malassezia fungus. This fungus is very common in hospitals [19].
4) Digestion And Nutrient Absorption
Coconut oil improves the absorption of fat-soluble vitamins (A, B, D, E, K) beta-carotene, CoQ10, minerals such as calcium and magnesium, and amino acids [20].
Coconut oil is used to treat malnutrition and malabsorption syndrome in children and is a common ingredient included in-hospital feeding formulas for premature and low birth weight babies. Intravenous MCT oils are used for very malnourished people [21].
Post-surgery, consumption of coconut oil leads to faster growth, weight gain, and improved nutritional status than other fats [22].
Patients with bile acid malabsorption do best when MCTs, as found in coconut oil, are their primary source of fat [23].
Similarly, those with pancreatic insufficiency respond well to foods rich in MCTs [24].
Individuals with liver disease are able to absorb the types of fats found in coconut oil better than other longer chain fatty acids [25].
5) Skin Health
Topical treatments containing coconut oil show great potential for healing wounds and combatting local bacterial infections [17].
Virgin coconut oil, applied daily for eight weeks, was an effective treatment for mild to moderate atopic dermatitis (eczema) in 117 patients [26].
In rodents, topically applied coconut oil speeds up wound healing time by speeding up collagen cross-linking, and increasing glutathione levels [27].
One of the main constituents of coconut oil, lauric acid, is effective against the bacteria that cause acne (P. acnes) [28].
Coconut oil enhances the absorption of other topical treatments, such as Vitamin E and curcumin [29, 30].
6) Hair Health
In preliminary research, coconut oil was shown to be more effective at reducing hair damage than mineral or sunflower oil. It reduced protein loss for both undamaged and damaged hair. These benefits may be due to the high lauric acid content [31].
It may be such an effective hair treatment because, unlike mineral oil, it actually penetrates the shaft of the hair [31].
A spray containing coconut was a more effective method for killing head lice than conventional treatments in 100 study subjects [32].
7) Oral Health
Coconut oil, when used as a mouthwash (oil pulling), reduces the amount of plaque-forming bacteria in the mouth, with the effects comparable to those of chlorhexidine [33].
In a similar study, 60 individuals aged 16-18 years with gum inflammation were instructed to do oil pulling with coconut oil for 30 days. At the end of the study, both inflammation and plaque markers were significantly decreased [34].
8) Wellbeing
In one trial, 60 women undergoing chemotherapy for breast cancer consumed 20ml of coconut oil per day. This resulted in better quality of life, fatigue, sleep, loss of appetite, sexual function and body image [35].
Effects on Heart Health
For decades, coconut oil was demonized for its high saturated fat content. However, there is no concrete link between the consumption of saturated fat and heart disease [36, 37].
A natural experiment that helps prove coconut oil’s safety has been taking place in many tropical countries for decades: Many Polynesian populations consume high percentages of calories from coconut oil (up to 60%), and yet have low levels of heart disease [38].
Virgin coconut oil stabilizes blood pressure and improves blood vessel function in rats fed a diet high in oxidized palm oil [39].
Current evidence supports the idea that the diseased heart is energy deficient. Coconut oil, with its rich source of ketogenic MCTs, might offer an important alternative fuel source for the heart [40].
On the other hand, there’s solid evidence to suggest that partly replacing saturated fat with polyunsaturated fatty acid significantly reduces the risk of heart disease [41].
Blood Lipids
According to preliminary research, coconut oil may increase HDL (good cholesterol) more than safflower and other vegetable oils [42, 8].
In humans, a diet rich in coconut oil raised HDL but also total and LDL cholesterol more than the beef fat and safflower oil; it caused less of an increase in triglycerides than a diet rich in beef fat [43].
After 40 days on a diet rich in coconut oil, rats showed improved lipid profiles. This included: reduced total cholesterol, triglycerides, phospholipids, LDL, and VLDL cholesterol levels and increased HDL cholesterol. The authors suggested these changes might be due to the polyphenol content of coconut oil [44].
Rats fed a diet rich in virgin coconut oil had significantly lowered levels of total cholesterol, LDL & VLDL cholesterol, Apo-B, and triglycerides, compared to rats fed copra oil, olive oil and sunflower oil [45].
A diet high in coconut milk was also able to decrease LDL and increase HDL in animal studies [46, 47].
Animal and Cellular Research (Lacking Evidence)
The following health effects have been observed in animal and cell-based studied only; they should not be interpreted as supportive of actual health benefits in humans until more research is done.
Blood Sugar Control
Coconut oil-rich diet prevented the negative impact of diabetes on blood lipids in mice [48].
After 21 days on a diet rich in virgin coconut oil, rats had reduced blood glucose levels [49].
MCTs, which are abundant in coconut oil, help maintain insulin sensitivity and blood glucose control, according to preclinical and clinical studies. Still, this doesn’t mean coconut oil would have the same effect in humans [50, 51].
Oxidative Stress
One study found that dietary virgin coconut oil improved the antioxidant status of rats more than three other oils. It increased glutathione (master antioxidant) levels, thus protecting against oxidative stress [52].
Joint and Bone Health
One study gave coconut oil polyphenols to arthritic rats. These rats showed reduced levels of CRP (an inflammatory marker) and white blood cells, and also reduced the expression of inflammatory genes such as COX-2, iNOS, TNF-α and IL-6 [53].
Oxidative stress and free radicals have been associated with the onset of osteoporosis (bone disease). Rats given virgin coconut oil show improved bone health. This is probably because of virgin coconut oil’s high antioxidant content [54].
Another study found that coconut oil prevented lipid peroxidation and increased the antioxidant enzymes in rats with osteoporosis [55].
