Fats – Facts and Myths

Fats, along with carbohydrates and proteins, are a key macro-nutrient found in food. Fats play important roles in our bodies, influencing a large number of the body’s physiological processes, from hormone regulation to nutrient absorption. This article unravels the intricacies of fats, explores the distinctions between various types of fats, debunks myths, and sheds light on the importance of embracing a balanced and informed approach to fat consumption.

What are fats?

Fats are a type of organic molecule comprised primarily of Carbon, Hydrogen and Oxygen atoms. The basic building block of fat molecules are fatty acids, which are hydrocarbon chains of varying lengths.

The role of fats in our bodies

Fats play multiple important roles in the functioning of the human body:

• Storehouse of energy: Fats are high in energy content. 1 gram of fat provides 9 kCal of energy, more than 2 times the energy content of carbohydrates and proteins. This makes fats the preferred format for energy storage in the body.
• Cell structure and function: Phospholipids and cholesterol are essential components of cell membranes, which provide structural integrity to cells and enable the flow of nutrients and communication to the cell
• Hormone synthesis: Cholesterol is the building block for many hormones such as oestrogen, progesterone, testosterone and cortisol
• Absorption of key nutrients: Fat soluble vitamins (Vitamins A, D, E, K) require fats for their optimal absorption in the digestive tract
• Temperature regulation: The body’s fatty reserves – its adipose tissue – play an important role in providing insulation and temperature regulation in cold environments
• Skin, brain and neural health

Types of Fats & their Health Implications

Food packages are required to declare their fat content, specifically their saturated fat, trans fat and cholesterol. But what do these terms mean? And what are their health implications?

Cholesterol

The liver converts excess macro-nutrients in the body – fats, carbohydrates and proteins – into cholesterol. Cholesterol is produced in two forms – the “bad” form, or Low Density Lipoprotein (LDL); and the “good” form or High Density Lipoprotein (HDL). LDL is believed to lead to clogged arteries and increased risk of heart disease and stroke, while HDL is a cholesterol cleanser – it takes cholesterol from parts of the body where there is too much of it to the liver, where it is disposed off.

Saturated Fats

What are Saturated Fats? A little bit of organic chemistry here. Fat molecules are made up of fatty acids, which are long links of Carbon atoms connected to each other, like a bunch of children standing in a straight line, holding hands. Unlike children, Carbon atoms have 4 ‘hands’, and while two of these hands are holding on to adjacent carbon atoms, the other two hands are connected to Hydrogen atoms. In other words all the extra hands of Carbon atoms in this chain are ‘saturated’ with Hydrogen atoms.

Saturated fats come from mostly animal sources, including red meat and dairy fats (butter, ghee, cream, cheeses); but also some plant sources such as palm oil, coconut oil and cocoa butter.

Western science has for long linked diets high in saturated fats to LDL cholesterol levels in the blood and ultimately to obesity and cardiovascular disease. However, recent research has shown that some saturated fats, such as the ones in ghee, are actually beneficial (more on this in a later section).

Unsaturated Fats

To understand unsaturated fats, we continue with the analogy of 4-handed carbon atoms. Again, these are lined up in a long line, holding hands with each other. Now consider a sequence of 4 Carbon atoms, say numbers 6, 7, 8 and 9 in the line. 6 and 7 are holding each other with one hand, as are 8 and 9. 7 and 8, however, decide to hold each other not with one hand but with two, leaving only their fourth hand each to hold on to Hydrogen atoms. This gives rise to a mono-unsaturated fat molecule. If more than one pair of carbon atoms is similarly double-linked, the resulting molecule is poly-unsaturated.

Omega-3 oils and Omega-6 oils are two types of poly-unsaturated fats that cannot be synthesized by the body on its own, and must be consumed as part of the diet. These fats play a key role in various bodily functions, including heart health, cancer prevention, cognitive function, skin health, and obesity prevention.

Prominent sources of mono-unsaturated fats include olive oil, mustard oil, avocados, brazil nuts, peanuts; and of poly-unsaturated fats include mustard, corn and sunflower oil; flaxseeds; walnuts, almonds and cashews; and fish (especially oily fish such as sardines).

Diets high in unsaturated fats are linked to higher levels of blood HDL.

Trans Fats

Trans fats are a type of unsaturated fat, where the configuration of the double bond is such that the hydrogen atoms are on opposite sides of the carbon chain. Unlike other unsaturated fats, trans fats raise the levels of LDL cholesterol in the blood.

Trans fats are found naturally at low levels in some products of animal origin, such as meats and dairy products. The biggest source of trans fats in our diets, however, are in partially hydrogenated vegetable oil products, such as Vanaspati and Margarine, which are extensively used in the baking industry.

Confusing? Here’s a diagram that summarises the linkage between the fats in our diet and the presence of LDL / HDL cholesterol in our bodies.

Some common questions about fats

Have any other questions about fats that have been bothering you? Write in at planit@planit.club.