Coconut oil belongs to a group of vegetable oils that has an abundance of lauric acid. A study has shown that consumption of solid fat rich in lauric acid resulted in a more favourable serum lipid profile in healthy men and women than with solid fat containing trans-
fatty acids [14
]. An emerging medicinal product of importance from coconut is virgin coconut oil (VCO) which is cheap, easily available, and widely used as over-the-counter complementary medicine in the tropics and many foreign markets [15
]. Of all different types of coconut oils, VCO contains the highest proportion of medium chain fatty acids, with MCFA content being as high as 85.1% in VCO (). Hence this oil naturally contains a mixture of MCFA and LCFA in a ratio of 3
1. MCFAs are rapidly absorbed in the intestines even without catalyzation by the pancreatic lipase enzyme. LCFAs, on the other hand, required pancreatic lipase for absorption. They are carried by the lymph to the systemic circulation in chylomicrons and eventually reach the liver where they either undergo beta oxidation, biosynthesis to cholesterol, or are repackaged as triglycerides. MCFAs are carried by the portal vein to the liver where they are rapidly oxidized to energy. Unlike LCFAs, MCFAs do not enter the cholesterol cycle and they are not deposited in fat depots [7
This open label pilot study attempted to find out the efficacy of VCO on reduction of weight and anthropometric markers of obesity in participants after 4 weeks of 30
mL in three divided doses daily VCO consumption. All the participants in this study were instructed to continue their normal daily diet and physical activities to minimize possible weight reduction and change in blood lipid profile which could be attributed to reduced calorie intake or increased energy consumption. Only WC was significantly reduced after four weeks of VCO consumption with a mean reduction of 2.87 ± 4.95
cm or 0.97% reduction from baseline measurement. There was a nonsignificant decrease in FM and body fat percentage with a nonsignificant increase in FFM. This indicated that VCO consumption reduced body fat especially abdominal fat since WC was significantly decreased. The effects on triglyceride, total cholesterol, LDL, and HDL were almost negligible indicating that VCO did not affect lipid profiles despite being an oil-based food source.
When the differences were analyzed according to gender, WC was significantly reduced in males but not in females. This difference was still seen only in men when analyzed in subgroups of males and females with BMI ≥ 30. The significant reduction in WC may be attributed to the nonsignificant reduction in weight and BMI among the males. This finding was important since for a given WC, the visceral adiposity was higher in males of Asian ethnic [5
]. The significant reduction of WC is considered modest given the short duration of this study. Furthermore, all males in the cohort are larger (BMI ≥ 30
) and therefore are more resistant to weight loss. Few studies exist in males on the optimal weight or BMI or WC reduction for a given weight loss intervention. The “Gutbuster” programme in Australia uses waist circumference as a target to encourage weight management in men, with a target of 1% waist reduction a week [18
]. Colman et al. found that a loss of 9
kg weight reduced waist circumference by 7
cm in men [19
]. A nonsignificant increase in total cholesterol, LDL, and HDL were also observed but the overall increase was too small. The effects of VCO on lipid profiles may need a longer time to be observed. An increase in HDL level but a reduction in total cholesterol and LDL levels after consumption of coconut oil was reported in experimental animals [20
]. Furthermore, the increase in LDL may be due to a different form of lipoprotein not associated with increase in cardiovascular risk since there were animal studies which demonstrated that the increase in LDL level after VCO was not associated with aortic atherosclerosis [21
In contrast, females exhibited different anthropometric profiles and lipid profiles after VCO consumption when compared to their male counterparts. Even though the reduction in WC was larger compared to males it was not statistically significant. When comparing females with BMI ≥ 30 and BMI < 30, the reduction in WC was greater in females with BMI < 30 but it was not statistically significant. The larger reduction in WC was not associated with a decrease in BMI or weight but was associated with a nonsignificant increase in FFM and a nonsignificant decrease in FM and body fat percentage. The data appeared to indicate that females in general lose more of their body fat with VCO and females with a lower BMI may lose more abdominal fat. This was not reflected on their BMI or WHR in contrast with their male counterparts. This supports the evidence that different indices are applicable to different gender and ethnic groups [6
]. However, the insignificant reduction in WC can also be explained by the relatively high-standard deviation suggesting that there was a high variability of WC reduction among females who took VCO (). In addition, the total cholesterol and LDL appeared to decrease in females who consume VCO with triglycerides and HDL almost unchanged. A study using coconut oil in obese women demonstrated a reduction of abdominal fat with unchanged lipid profiles providing support for similar findings in the current study [9
]. This also reflected that females benefited from VCO in a manner different from males [23
Comparison of mean differences in anthropometric measurements and lipid profile values in 7 males and 13 females after VCO consumption.
This pilot study also attempted to assess the safety aspects of using VCO especially biochemical changes and organ functions including the renal and liver functions. Results have shown that all measured variables did not demonstrate any increase from baseline but interestingly two biochemical markers were shown to reduce after being given VCO. These markers were creatinine and ALT levels. Animal studies did not have any similar findings as in humans but this may have been because of the differences in the type of coconut oil and doses used [25
]. This finding in the humans however cannot be explained and merits further study.
There were some limitations to this study. Firstly, there was no long-term followup on the weight, anthropometric, and lipid profile in the subjects. The full effects of VCO may not be realized without a longer duration of followup. Even though no serious side effects were reported from the volunteers after one month of VCO consumption, a long-term followup will be able to determine the safety of using VCO for long periods. Secondly, the duration of VCO consumption was probably too short as this is a pilot study. A longer period of VCO consumption may reveal more clinical differences not shown in a short-term study. In addition, a longer period of study can assess the tolerability of subjects toward coconut oil. It appeared that one month of VCO was well tolerated by all the subjects in this study. Thirdly, the number of subjects was too small contributing to the many nonsignificance results seen. Finally, the open-label design and lack of control group may introduce bias to the results. Therefore, a properly designed randomized placebo-controlled trial should be performed to further confirm the beneficial effects of VCO.
In conclusion, VCO is a cheap oil source containing high concentration of MCFAs which in the current study had shown beneficial effect in WC reduction especially in males without any deleterious effect to the lipid profile. VCO is also safe to use for the period of study without any deleterious effects on biochemical and organ functions.