Coconut Oil

Is It A Healthy Choice for Cooking?

What is coconut oil?

Coconut oil refers to the oil extracted from the edible, fleshy kernel (“meat”) of a coconut. In recent years, coconut oil has increased in popularity due to reputed health benefits, ranging from supporting weight loss to slowing down progression of dementia. Furthermore, it can be a tasty addition to a number of meals, but it should be used with care. 

Types of coconut oil

Coconut oil can be divided into refined and unrefined oils, depending on the extraction methods. 

unrefined coconut oil

Unrefined coconut oil is also known as cold-pressed or virgin coconut oil, which is made by mechanically pressing the fresh coconut meat soon after picking. Since no chemicals or heat are used to treat the oil, it retains more of the compounds naturally present. Virgin coconut oil smells and tastes like coconut, has the highest levels of antioxidants (polyphenols) and is most commonly studied in health research. The drawbacks are virgin coconut oil is more expensive and has a low smoke point of 177oC, making it not suitable for high-temperature cooking. 

refined coconut oil

Refined coconut oil is also known as RBD (refined, bleached, deodorized) coconut oil, which involves high heat and chemicals. It is the most popular form of coconut oil worldwide. It is usually made from dried copra and coconut kernel. To extract the oil, the coconut kernel is placed in a hydraulic press with additional heat. The crude oil is then repeatedly filtered to obtain a clean filtrate. Besides, the oil is also bleached in the process. Then, it is heated to a very high temperature, which deodorizes the oil and also kills the germs or fungal spores within it. Thereafter, sodium hydroxide is added and it is further filtered to get rid of free fat acids to prolong its shelf life. To obtain the most oil, chemical solvents may be used to extract as much oil as possible from the meat. In some cases, the oil is hydrogenated eventually to ensure no unsaturated fatty acids are left in the oil, which significantly prolongs its shelf life. Nonetheless, the hydrogenated oil may contain trans-fat, which is harmful to the health.

During bleaching process, the nutrients such as polyphenols are damaged. Thus, refined oil does not contain as many beneficial health properties as unrefined oil. The good things are coconut oil has milder flavor and slightly higher smoke point (232°C). Hence, it can withstand high heat and can be used for high-heat cooking.

Nutrition facts

Fatty Acid Breakdown:

Saturated: 92%
Monounsaturated (e.g. omega-9): 6%
Polyunsaturated (e.g. omega-3, omega-6): 1.6%

   Omega-3: Omega-6 ratio = NA (virtually no omega-3)

For immense health benefits, please choose unrefined coconut oil. It is organic and retains most of the nutrients.

Benefits

The health benefits of coconut oil (especially unrefined coconut oil) are:

  • Rich in medium chain triglycerides (MCTs)

Most saturated fats in coconut oil are MCTs, which have different effects than most saturated fats which are known as long-chain triglycerides. MCTs can be easily absorbed and transported throughout the body. It can serve as an instant source of energy or can be converted into ketones to fuel the brain. Furthermore, MCTs also help increase HDL (good) cholesterol in the blood, which is associated with reduced risk of heart disease.

 

  • Boost fat burning

A study showed that consuming 15-30g of MCTs daily increased calories burned over 24 hours by as much as 5%, totaling about 120 calories per day1. Another study showed that MCTs helped reduce total body fat, subcutaneous fat (jiggly fat under the skin) and visceral fat (also known as belly fat)2. Visceral fat, the deep abdominal fat that lodges in the abdominal cavity and around organs, is more of a health concern than subcutaneous fat. High accumulation of it is extremely harmful to health and is linked to chronic diseases.

 

  • Reduce hunger

MCTs in coconut oil break down into ketones that can have an appetite reducing effect3. A study showed that men who consumed the most MCTs ate on average 256 fewer calories per day4. Another study showed those who ate the most MCTs during breakfast consumed fewer calories during lunch5.

 

  • Support weight management

Since coconut oil boosts fat burning and reduces appetite, it should support weight loss in the long term. In fact, a study showed that MCTs promoted modest reductions in body weight, waist circumference and hip circumference2. In another study conducted on women with abdominal obesity, dietary supplementation with 30 ml (2 tablespoons) of coconut oil per day over a 12-week period led to a significant reduction in both BMI and waist circumference6. Yet another study on obese males also showed reduction in waist circumference after 4-week consumption of 30ml coconut oil daily7. However, do bear in mind that coconut oil is still high in calories and it is recommended to take in moderation. 

 

  • Improve blood lipid profile

A study showed that coconut oil reduced total and LDL (bad) cholesterol while increasing HDL (good), compared to soybean oil8. Another similar study also showed increased in HDL cholesterol9 level, this suggests that consumption of coconut oil helps improve metabolic health and lowers the risk of heart disease. Nonetheless, the effects of coconut oil on maintaining healthy cholesterol are still contradicting.

 

  • Improve brain function of Alzheimer’s patients

Alzheimer’s patients appear to have reduced ability to use glucose for energy in certain parts of the brain. Scientists have hypothesised that ketones could provide an alternative energy source for these malfunctioning brain cells and reduce symptoms of Alzheimer’s disease10.  A study showed consumption of MCTs led to an improvement of brain function in patients with mild Alzheimer’s disease11. Nonetheless, this is a preliminary study and there is no evidence to suggest that coconut oil helps with Alzheimer’s disease. 

 

  • May reduce seizures

MCTs in coconut oil can increase the concentration of ketones in the blood, which could help reduce the rate of seizures in epileptic children12.

 

  • Manage infection

Lauric acids make up about 50% of the fatty acids in coconut oil, they can kill harmful pathogens, including bacteria, viruses and fungi13. Studies have shown that lauric acids managed to kill the harmful bacteria Staphylococcus aureus14 and yeast Candida albicans, which is a common source of yeast infections in human beings15

The drawbacks 

 

  • Lack of omega-3 fatty acids

Although coconut oil is high in MCTs, a healthy type of saturated fatty acid, it does not actually contain any omega-3s. According to a study16, most of the world’s population exhibits low blood levels of the omega-3s EPA and DHA. The modern diet consists of high amounts of omega-6, resulting in a very high omega-6 to omega-3 ratio, which could promote the development of many diseases, including cardiovascular disease, cancer, inflammatory and autoimmune diseases. On the other hand, increased levels of omega-3s (i.e. a lower omega-6/omega-3 ratio) promote suppressive effects on inflammation.

To increase omega-3 intake, one of the easiest and effective ways is to use cooking oils that are high in omega-3s in daily cooking.  If you always experience dry, rough, scaly skin or heightened feelings of anxiety, you may be lacking in omega-3s and supplementing with good cooking oils rich in omega-3s is highly recommended. Otherwise, you may complement coconut oil with omega-3-rich oil to optimise omega-6/omega-3 ratio. 

 

  • Contradictory health claims 

There are many conflicting reports about whether coconut oil can lower total cholesterol and LDL (bad) cholesterol and increase HDL (good) cholesterol levels. Some experts say that the fats in coconut oil are healthy and less likely to add to fat build-up in the body. Meanwhile, other experts suggest that coconut oil should be avoided due to its high levels of saturated fat, which has been demonised to increase cholesterol, especially LDL cholesterol. Since the research has not been definitive, it is good to stay updated on new findings on the effects of it on cholesterol level. This will help you to get a clearer picture of whether you should add coconut oil into your diet. 

 

  • Virgin coconut oil is not suitable for high-heat cooking

Virgin or unrefined coconut oil has a low smoke point (177°C), making it unsuitable for high temperature cooking, such as stir-frying and deep-frying. Meanwhile, refined coconut oil with a high smoke point of 232°C is suitable for all cooking methods, including deep-frying, roasting and grilling. Nevertheless, most of the beneficial MCTs in coconut oil are lost during the refining process, making it less nutritious than unrefined oil. 

References:

1.Eur J Clin Nutr.1996 Mar;50(3):152-8.

2. J Acad Nutr Diet.2015 Feb;115(2):249-63.

3. Obesity (Silver Spring).2018 Feb;26(2):269-273.

4. Int J Obes Relat Metab Disord.1996 May;20(5):435-44.

5. Am J Clin Nutr.1998 Aug;68(2):226-34.

6. Lipids.2009 Jul;44(7):593-601. 

7. ISRN Pharmacol. 2011; 2011: 949686. 

8. Lipids.2009 Jul;44(7):593-601.

9. Nutr Hosp.2015 Nov 1;32(5):2144-52.

10. Ann N Y Acad Sci.2016 Mar;1367(1):12-20.

11. Neurobiol Aging.2004 Mar;25(3):311-4.

12. J Med Assoc Thai.2016 Feb;99(2):159-65.

13.  Antimicrob Agents Chemother. 1972 Jul; 2(1): 23–28.

14. J Bacteriol.2000 May;182(9):2668-71.

15. J Med Food.2007 Jun;10(2):384-7.

16. Prog Lipid Res.2016 Jul;63:132-52.