Fatty acids

Fatty acids are essential for the normal functioning, growth and repair of the cells in the body. They can be obtained either from food or dietary supplements. Fatty acids are composed of a chain of carbon atoms bonded to hydrogen atoms, with a methyl group attached at one end and an acid group at the other. As such, the number of hydrogen atoms determines whether the fatty acid is saturated or unsaturated.

There are several different families of fatty acids:

• Saturated fatty acids (e.g. palmitic and stearic acid)
• Monounsaturated fatty acids (e.g. oleic acid)
• Polyunsaturated fatty acids (e.g. omega-3 and omega-6)
• Trans fatty acids

Saturated fatty acids are bonded to the maximum number of hydrogen atoms possible. Unsaturated fatty acids, on the other hand, have one or more double bonds between carbon atoms, meaning that fewer hydrogen atoms can be bonded to the carbon. Saturated fatty acids are primarily found in animal products and processed foods such as butter, full-fat cheese, deli meats, lard, palm oil and coconut oil.

Monounsaturated fats contain only one double bond, whereas in polyunsaturated fats there are two or more double bonds. Monounsaturated fatty acids are obtained mainly from plant foods such as olive oil and oily fruits (e.g. olives and avocado).

Both omega-3 and omega-6 fatty acids are polyunsaturated fatty acids. The difference between them is based on the position of the first double bond in the fatty acid chain. The major dietary sources of omega-6 fatty acids include fats of animal origin (meat, egg, milk and dairy products), vegetable oils (coconut oil, sunflower oil, palm oil, rapeseed oil), and fat spreads (butter, lard, margarine, etc.). Omega-3 fatty acids can be found mainly in oily fish (e.g. salmon, mackerel and herring), and in certain seeds.

Hydrogenated fats are the most harmful to health. They are formed either by overheating of fat, or by industrial processing and hydrogenation of food. Additionally, they can occur through bacterial transformation of fats in the intestinal lumen of ruminants.