Palm oil holds a significant presence in India's edible oil landscape, constituting approximately 40% of total consumption. It remains a staple distributed under subsidised programmes, including the public distribution scheme in states like Tamil Nadu, benefiting many families below the poverty line. Moreover, palm oil plays a vital role in the food industry, appearing in a myriad of everyday products such as biscuits, cakes, and chips. 

Yet, myths persist, exaggerating its perceived negative effects on health. This begs the question: are these claims substantiated by science? How does palm oil truly affect our well-being? And how does it compare to other oils like coconut, groundnut, sesame, or vegetable oils such as canola or olive oil?

 Human use of oil dates back thousands of years, originating from the discovery that animal fat enhanced the taste of cooked food. Even now, in many parts of the world, animal fat like lard is commonly used as a cooking medium. Across different regions, indigenous oils like sesame, groundnut, coconut, and mustard were commonly used based on geographical availability. 

 Understanding palm oil composition

 Palm oil, extracted from the fruit of the oil palm tree, has a rich history dating back to West Africa more than 5,000 years ago. It became a valuable commodity during European trade in the 17th and 19th centuries, primarily for industrial purposes. While not native to Malaysia, palm oil cultivation was introduced there in the late 19th century, eventually making Malaysia the world's largest exporter.

 Understanding the production process is essential. Palm oil is derived from the fleshy pulp of the fruit, while palm kernel oil is extracted from the kernel. During refining, palm oil is separated into two components. One component, predominantly high monounsaturated fat oleic acid-based, is referred to as palm olein, which is our commonly used palm oil. The other component, rich in stearic acid, is known as palm stearin and finds application in the cosmetic industry due to its solid form at room temperature. Raw crude palm oil typically has a dark orange hue due to excess beta-carotene, akin to the vitamin A found in papaya and carrots. However, beta-carotene is often removed during refining to produce a clear oil widely used in the food industry and cooking.

 Additionally, palm kernel oil, extracted from the oil kernel of the palm fruit, shares similarities with coconut oil, being approximately 80% rich in saturated fat. However, palm kernel oil is primarily employed in the cosmetic industry for soap production rather than in the food industry.

 In essence, palm olein constitutes the liquid form of palm oil, characterised by its higher content of oleic acid, a monounsaturated fatty acid. This component serves as a common choice for edible purposes worldwide. Understanding the fatty acid composition of palm olein allows for meaningful comparisons with various other edible oils.

 Plant sources, such as palm oil, do not contain cholesterol.

 Before going any further, let's clarify fundamental concepts surrounding fats and lipids, as these terms can often cause confusion. Firstly, what are fats? Fats, also known as fatty oils, belong to the broader category of lipids. Lipids encompass two main types: fatty acids and steroids. While the term "steroid" may evoke associations with performance-enhancing drugs, in the context of lipids, it refers to a different class altogether.

 Fatty acids, which serve as the body's primary energy source, are commonly found in the form of triglycerides. Similar to carbohydrates, which provide energy through sugars found in cereals, millets, and fruits, fats offer an alternative energy source. Excess calories, whether from carbohydrates or other sources, are stored by the body as triglycerides.

Cholesterol, another lipid type, plays a structural role in cell membranes and serves as a precursor for essential hormones. Hormones regulating various bodily functions, including those governing reproductive processes and stress responses, are derived from cholesterol. It's essential to note that cholesterol is exclusively present in animal products; no plant sources naturally contain cholesterol. Hence, it is wrong to market a vegetable oil as cholesterol-free since none of these oils have cholesterol at all.

 When discussing fatty acids, they can be categorised based on their chemical structure into saturated and unsaturated fats. Saturated fats, characterised by single bonds between carbon atoms, tend to be solid at room temperature. In contrast, unsaturated fats feature one or more double bonds between carbon atoms and can be further divided into monounsaturated and polyunsaturated fatty acids, depending on the number of these double bonds.

 Traditionally, the composition of fatty acids has been associated with various heart diseases, including atherosclerosis. The hypothesis linking saturated fats to increased LDL cholesterol levels and subsequent heart disease gained prominence in the 1970s and '80s. Studies suggest that replacing saturated fats with unsaturated fats could lower LDL cholesterol levels and reduce cardiovascular risk.

 This led to a shift in dietary recommendations, advocating for oils rich in unsaturated fats like sunflower, canola, or rice bran oil over traditional sources of saturated fats like coconut oil or butter. While these recommendations aimed to improve heart health, they also influenced the transition in edible oil consumption patterns, reflecting broader dietary trends.

 Is the concern about SFAs in palm oil justified?

 Even today, many households harbour concerns about coconut oil and palm oil due to their high saturated fatty acid content, often associated with heart issues. But are these concerns justified? Renowned studies like the Framingham Heart Study, the Minnesota Coronary Survey, and the Sydney Heart Health Study, which led to the development of the diet-heart hypothesis in the 1980s, were reexamined and published in prestigious medical journals such as BMJ and shed light on this matter. Surprisingly, while replacing saturated fatty acid oils with vegetable oils rich in unsaturated fatty acids did indeed lower LDL cholesterol levels, each 30 milligramme reduction in cholesterol corresponded to a 22% higher risk of death from other causes. Moreover, there was no evidence of these interventions preventing heart attacks or coronary atherosclerosis.

 Replacing saturated fats with unsaturated fats may reduce cholesterol levels, but it doesn't necessarily translate to improved heart health. Despite these findings, the medical community remains wary of saturated fats and acknowledges the potential inflammatory effects of polyunsaturated fatty acids. 

 Let's compare the fatty acid composition of various oils to gain a clearer understanding. Coconut oil, comprising 90% saturated fat, 6% monounsaturated fat, and 2% polyunsaturated fat, stands out for its high saturated fat content. However, it also contains lauric acid and medium-chain triglycerides, which offer potential heart benefits, such as increasing HDL cholesterol and reducing triglycerides. 

 Now, considering palm oil, it contains 50% saturated fat, 40% monounsaturated fat, and 10% polyunsaturated fat. Monounsaturated fatty acids, predominantly found in olive oil, are currently favoured for heart health. But palm oil has an equivalent proportion of monounsaturated fats when compared with traditional oils like South Indian sesame oil, mustard oil, and groundnut oil, and only slightly fewer monounsaturated fats than olive oil. Hence, even on these grounds, palm oil does not seem to be a harbinger of doom. Even though it contains 50% saturated fat, robust meta-analysis studies suggest it doesn't significantly elevate LDL cholesterol or negatively impact lipid status when compared to other dietary oils.

 Here, we must also note that high triglycerides in the blood are always due to obesity and insulin resistance, which is one of the major risk factors for heart attacks. High triglycerides can be brought down only by reducing the carbohydrate content. Reducing the fat content or changing the oil source is not going to help in this regard.

 Therefore, it's not solely about the composition of fatty oils but also about their nuanced effects on health.

 Moderation and good lifestyle habits are key.

 The escalating rate of heart attacks is primarily driven by lifestyle factors such as obesity and metabolic syndrome, which are worsened by excessive refined carbohydrate consumption. Habits like indulging in high-carbohydrate snacks, adopting unhealthy eating patterns such as late-night eating, and leading sedentary lifestyles contribute to the obesity epidemic. These lifestyle factors outweigh the impact of oils, which are typically used in small quantities in our diets.

 Shifting the conversation towards promoting moderation and healthy lifestyle choices is essential. With a better understanding of the science behind these issues, we can redirect our efforts towards combating the true underlying factors and achieving lasting health improvements. 

 (Dr. Arunkumar A is an M.D. (paediatrics) from Bangalore Medical College and an MBBS from Stanley Medical College, Chennai. Currently working as a consultant paediatrician and nutrition specialist, he has guided more than 15,000 patients in the dietary management of obesity, diabetes, PCOS, dyslipidemia, fatty liver disease, and other lifestyle disorders.)