Coconut oil: what do we really know about it so far?

Food Quality and Safety, 2019, 3, 61–72 doi:10.1093/fqsafe/fyz004 Review Advance Access publication 22 April 2019 Review Coconut oil: what do we really know about it so far? Renan da Silva Lima and Jane Mara Block Correspondence to: Jane Mara Block, Department of Food Science and Technology, Federal University of Santa Catarina, Av. Admar Gonzaga, 1346, Florianópolis, SC, 88034-001, Brazil. E-mail: Received 13 November 2018; Revised 2 December 2018; Editorial decision 28 February 2019. Abstract In recent years, coconut oil has emerged as a potential ‘miracle’ food. Some media vehicles and health specialists assure that this fat is capable of promoting health benefits, such as weight reduction, cholesterol lowering, prevention of cardiovascular diseases, and anti-inflammatory effect, among others. These claims are used to market the product and boost its sales by coconut oil companies. However, governmental regulatory agencies in many countries are still sceptical about the benefits obtained by the consumption of coconut oil due to its high-saturated fatty acid content. In light of such controversy, this review focused on analysing the published literature on the alleged health claims, in order to investigate if there is enough scientific evidence to support them. It was verified that the metabolism of lauric acid, the major fatty acid in coconut oil, remains unclear. Many studies reported that the product was not efficient in weight loss. Also, it has been reported that the consumption of coconut oil increased low-density lipoprotein cholesterol, consequently increasing the risk of cardiovascular diseases. In general, the studies present conflicting results and there is a lack of long-term human-based clinical trials. Therefore, as a saturated fat, coconut oil should be consumed with moderation and the health allegations should not be used to market the product, once they are not scientifically proven so far. Key words: lauric acid; saturated fatty acids; medium-chain triglycerides; LDL cholesterol; cardiovascular diseases. Introduction Coconut is one of the most important foods in some tropical and subtropical countries, with the coconut tree being referred as the ‘tree of life’. In such places, coconut and its products (milk and oil, among others) are used in daily life by the general population for several purposes, such as cooking, hair and skin treatment, food ingredient, and folk medicine (DebMandal and Mandal, 2011). This plant is cultivated in more than 90 countries, yielding a total production of 59 million tons in the year of 2016. The production of coconut is heavily located in Asia, which was responsible for 83.8 per cent of the world’s coconut production in 2016. In this same year, Indonesia was the largest coconut producer with 16.6 million tons, followed by the Philippines (14.1 million tons), India (9.8 million tons), Brazil (2.5 million tons), and Sri Lanka (2.2 million tons) (Statista, 2018a). In recent years, coconut oil (CO), the main coconut product, has attracted the attention of the media and the population worldwide, especially in Europe and North America. Celebrities, digital influencers, and even doctors have endorsed the use of this oil as a cooking media in substitution to other vegetable oils and as a supplementary ingredient to be consumed with coffee and vitamin shakes. Blogs, internet videos, and articles are promoting the consumption of CO based on allegations that this product is capable of bringing several health benefits. These benefits include cholesterollowering effect, reduction of the risk of cardiovascular diseases (CVDs), weight loss, improvement of cognitive functions, action as an antimicrobial agent, and others (BBC News, 2018; Medical News Today, 2018; New Straits Times, 2018; SBS, 2018; The Indian Weekender, 2018). © The Author(s) 2019. Published by Oxford University Press on behalf of Zhejiang University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact 61 Department of Food Science and Technology, Federal University of Santa Catarina, Florianópolis, Brazil R. da S. Lima and J. M. Block, 2019, Vol. 3, No. 2 62 medium-chain fatty acids (MCFAs) as a weight reduction agent. MCFAs account for 62 per cent of CO’s fatty acid composition. The EFSA panel concluded that there is not enough evidence in human intervention studies to support that MCFAs show a positive effect in weight management. The statement concludes that this specific allegation is weak and not convincing (EFSA, 2011). In Brazil, the fourth largest CO producer, the Brazilian Society of endocrinology and metabolism (SBEM) and the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO) have also issued a position on the use of CO as a weight loss agent. Both health agencies support that there is not conclusive scientific evidence about this topic. Therefore, the use of CO should be restricted. SBEM and ABESO also do not recommend CO as a cooking media due to its high-saturated fatty acid composition. On the other hand, unsaturated vegetable oils such as soybean oil, olive oil, and canola oil are recommended to diminish the risk of CVDs (SBEM and ABESO, 2015). The scientific evidence on the supposed benefits of CO should be examined and more information should reach the population. In this review, the chemistry and the processing, as well as the published data on the major and minor health claims attributed to CO by the media, the general public, and the manufacturing companies are presented and discussed. History of CO In the late 19th century, the demand for edible oils was increasing in Europe and in the USA. At the same time, in tropical countries such as India, the Philippines, and Malaysia, among others, CO had already encountered many uses in folk medicine and as a cooking oil. Once Europeans became aware of the utilization of CO and its several applications, they started establishing coconut plantations in the Caribbean, Southeast Asia, and the South Pacific from the 1890s to the 1920s. After that, CO became an edible oil very popular in European countries and in the USA (Cassiday, 2015). The first CO boom lasted until the World War II started (around 1940), when the supply of the product was cut off to the West countries and a CO shortage took place. As a result, its price skyrocketed while the soy industry began to expand and develop, which was made possible by the modern technology employed in these oils’ processing (Oils and Fats International, 2018). Once the war was over, even though countries with high-coconut production Figure 1. Number of scientific papers about coconut oil through the years. (Scopus, 2018). Following t (...truncated)