Now; coconut oil is bad for your heart
A Colombo Medical Faculty team sifts fact from assumption through a systematic review & metabolic analysis of human Clinical Trials
The fat is well and truly in the fire. Over the years, coconut oil has been swirled and twirled in controversy…….. it is bad for your health, we were told many years ago, and more recently, it is “very” good for your health.
The lid has finally been blown off the ‘ miracle’ that is coconut oil by a local team of experts who have pored over scientific publications, in a literature review to reveal fact from fiction.
Fact – the consumption of coconut oil can be one of the risk factors for cardiovascular diseases ( heart attacks and stroke) in South Asia including Sri Lanka, a team led by Prof. Ranil Jayawardena, Professor in Nutrition, Faculty of Medicine, University of Colombo, has found. He is also a Visiting Professor at the Institute of Health and Biomedical Innovation, Queensland University of Technology, Australia.
His team drawn from the Colombo Medical Faculty comprised his research student and nutritionist Hasinthi Swarnamali from the Health and Wellness Unit and Dr. Priyanga Ranasinghe, Senior Lecturer, Department of Pharmacology.
“Coconut oil consumption results in significantly higher total cholesterol, low- density lipoprotein ( LDL) and high- density lipoprotein ( HDL),” their in-depth study, ‘Effect of coconut oil on cardio- metabolic risk: A systematic review and meta- analysis of interventional studies’ published online in mid-October in the prestigious scientific journal ‘ Diabetes & Metabolic Syndrome: Clinical Research & Reviews’, has uncovered.
Explaining the backdrop in which, they carried out their review, Prof. Jayawardena tells the Sunday Times that the leading cause of deaths globally is cardiovascular and circulatory diseases, while they are also playing a role in premature deaths worldwide.
“Sri Lanka is no exception. Non
The high level of evidence produced by RCTs override the isolated evidence, he says, while spotlighting the fact that many coconut oil brands in Sri Lanka, market their products on their supposed health benefits. On their labels are statements such as “Good for cooking”
communicable diseases (NCDs) are estimated to account for 83% of all deaths in our country, while of the different NCDs, cardiovascular diseases are a leading cause of death and disability,” he points out, referring to a recent publication on diabetes and cardiovascular disease.
The publication which was based on a study conducted by Consultant Endocrinologist & Diabetologist Dr. Prasad Katulanda had found that:
Just over 3 in 4 Sri Lankan adults (77.4%) have some form of dyslipidemia (an abnormal amount of lipids including triglycerides and cholesterol).
Prof. Jayawardena reiterates that as Sri Lankans are becoming more vulnerable to cardiovascular diseases, there is significant new pressure on the health system as well.
Looking closely at the food we eat, he says that it is well-known that the sources of fat in our diet play a key role in the incidence and severity of cardiovascular diseases.
“Coconut oil is one of the most commonly used fat sources by Sri Lankans and has emerged as a potential ‘ miracle’ oil in recent years. Health specialists and the media assure that this fat is capable of promoting health benefits. Blogs, videos and articles promote the consumption of coconut oil based on assumptions that it is able to bring several health benefits such as a cholesterol-lowering effect, reduction in the risk of cardiovascular diseases, weight loss, improvements of cognitive functions, action as an anti- microbial agent and others,” he points out. Then, comes the big ‘but’.
But, cautions Prof. Jayawardena, stressing that “we have to understand the level of evidence. Systematic review and meta-analysis of randomized clinical trials ( RCTs) are the ultimate evidence, although isolated small studies have different conclusions”. (Systematic reviews and meta- analyses present results by combining and analyzing data from different studies conducted on similar research topics.)
The high level of evidence produced by RCTs override the isolated evidence, he says, while spotlighting the fact that many coconut oil brands in Sri Lanka, market their products on their supposed health benefits. On their labels are statements such as “Good for cooking”.
This is while coconut oil has also attracted the attention of the scientific community, with a rapid growth in the volume of scientific articles which have given contradictory evidence down the years.
In their review, the team had examined over 1,000 research articles, selecting 23 of the human clinical trials for inclusion in the analysis. Of the few publications on coconut oil and cholesterol, there had been two local interventional dietary studies by Prof. Shanthi Mendis and co-workers three decades ago.
Elaborating on the two local studies, Prof. Jayawardena says that the first had found that feeding coconut oil to young adults as against corn oil increased the total cholesterol, LDL and HDL, but decreased triglycerides. In the second study too, it had been found that feeding soya fat as against coconut fat had similar results. However, the only variation in the findings of the second study had been that there was also an increase in triglycerides.
“These findings had not been well communicated to the public as well as exchanged among experts to facilitate decision- making by clinicians,” he laments.
With regard to isolated evidence about the benefits of coconut oil, he says that it is natural for people to be confused. However, the point of reliability depends on the level of evidence and “we have to think of the hierarchy of evidence without simply comparing results”.
Stressing that their results came f rom a systematic review and meta- analysis from findings of studies considered to be of the “highest quality evidence”, he says that then there is no value in comparing the results of isolated evidence.
Urging that there is “great potential” to explore the effect of the consumption of coconut oil on cardio- metabolic health, which should also be a national priority, Prof. Jayawardena adds that it would pave the way to uncover the “missing link” between the high prevalence of dyslipidemia and cardiovascular diseases among Sri Lankans.
(The citation for the article is: Jayawardena et al. Effect of coconut oil on cardio-metabolic risk: A system
atic review and meta-analysis of interventional studies. Diabetes &
Metabolic Syndrome: Clinical Research & Reviews (2020): Volume
14:6; 2007-2020.)