Nutrient - Your guide to the omegas
Fats can be classified as either saturated or unsaturated. Unsaturated fats are ‘good’ sources of fats in our diets that lower the risk for certain diseases, and can be further classified as monounsaturated or polyunsaturated. Monounsaturated fatty acids have only one double bond, and polyunsaturated fatty acids contain two or more double bonds. The double bond changes the fat molecule’s shape by putting a “kink” in the fatty acid chain, preventing the unsaturated fats from packing closely together, making them liquid at room temperature.
Monunsaturated fatty acids
Omega 7 fatty acids
Omega 7 fatty acids have their double bond located seven carbon atoms from the end of the carbon chain (omega is Greek for “end,” hence the name). The most well-known omega 7 fatty acid is palmitoleic acid. Sea buckthorn oil has a high content of palmitoleic acid, which makes up between 20-45% of its total fatty acids. Other good sources include fish and some nut oils. Research suggests that palmitoleic acid may help support healthy blood pressure levels. Sea buckthorn oil also contains a variety of health-promoting phytochemicals, including carotenoids and vitamin E (tocopherols and tocotrienols).
Omega 9 fatty acids
Omega 9 fatty acids have their double bond located nine carbon atoms from the end of the carbon chain. Oleic acid is the most common omega 9 fatty acid. Olive oil is the richest dietary source of oleic acid, which makes up 55-80% of olive oil. Other good sources include avocados and nuts. Omega 9 fatty acids help to reduce cardiovascular disease risk factors.
Extra-virgin olive oil is also a good source of phenols. These are plant chemicals with antioxidant activity, which may explain why olive oil helps protect LDL (“bad”) cholesterol from free radical-induced damage that sets off the artery-clogging process of atherosclerosis.
Polyunsaturated fatty acids
Omega 3 fatty acids
Omega 3 fatty acids are a specific type of dietary polyunsaturated fatty acid, necessary for human health. They have their first double bond three carbons from the end of the chain. Some omega 3 fatty acids are termed “essential fatty acids” because they cannot be produced by the body, and must therefore be obtained from the diet.
What are the different types of omega 3 fatty acids?
There are two major types of omega 3 fatty acids that occur in plants and oily fish:
Alpha-linolenic acid (ALA) is an essential plant-derived omega 3 fatty acid and the parent compound for the omega 3 series of fatty acids.
Eicosapentaenoic acid(EPA) and docosahexaenoic acid (DHA) are known as the “long-chain” or “marine” omega 3 fatty acids, since they are mainly found in marine sources.
Where do I get my omega 3s?
Flax seed oil is the richest source of ALA, which makes up 55-60% of its total fatty acids. Hemp seeds and walnuts, as well their oils, are also good sources. ALA is found in smaller quantities in certain vegetable oils, dark green leafy vegetables and grass-fed animal fat. Oily, dark-fleshed fish, such as herring, kippers, mackerel, pilchards, anchovies, salmon, sardines and trout, are the richest dietary source of EPA and DHA.
What are the health benefits?
Omega 3 fatty acids have a broad spectrum of potential health benefits associated with their consumption. These protective fats may help to reduce fatty deposits in the blood, regulate the heartbeat, prevent dangerous blood clots and keep the arteries smooth and supple. Omega 3 fats may also have a protective effect against depression, Alzheimer’s disease, autoimmune diseases, such as lupus and rheumatoid arthritis, age-related macular degeneration and inflammatory conditions.
What makes long-chain omega 3 fatty acids so special?
Omega 3 fatty acids are important structural components of cell membranes. DHA is the major polyunsaturated fatty acid in membranes, especially those in the eye and brain, playing a crucial role in maintaining membrane fluidity. Membrane fluidity is essential for proper functioning of the eyes and brain. Long-chain omega 3 fatty acids also provide the starting point from which some hormones are made, including ones that regulate inflammation, blood pressure and blood clotting. They can also modify gene expression.
Are plant- and fish-derived omega 3s equally beneficial?
It remains uncertain whether plant-derived omega 3 fats are equally beneficial as those present in oily fish. Studies suggest that ALA is a cardio-protective nutrient with direct health benefits, including improved vascular tone, inflammatory responses, and protection against heart rhythm disturbances. It also has indirect health benefits through its partial conversion to EPA and DHA, which, according to recent research, may be increased in non-fish eaters.
Omega 6 fatty acids
Omega 6 fatty acids are another form of dietary polyunsaturated fatty acid, and, like the omega 3 fatty acids, some are considered “essential fatty acids”. They have their first double bond six carbons from the end of the chain. Omega 6 fatty acids include linoleic acid (LA) and gamma-linolenic acid(GLA). LA is an ‘essential fatty acid’ and the parent compound for the omega 6 series of fatty acids. Good sources of LA include sunflower seed oil, which normally contains 60-75% LA, and hemp seed oil (45-65%). Starflower oil (borage oil) is the richest supplemental source of GLA, containingat least 23%GLA. Hemp seed oil also contains some GLA, as do evening primrose oil and blackcurrant oil.
There is strong evidence that omega 6 fatty acids help shape healthy cholesterol levels, reduce inflammation and are protective against coronary heart disease.The body uses essential fatty acids to make various hormone-like substances called eicosanoids. These substances influence inflammation and pain in different ways. GLA may help to increase production of more favourable anti-inflammatory eicosanoids.
Putting it into practice
Fat is an important component of a healthy diet. Research shows that the type of fat you consume is more important than the amount. The majority of saturated fats can increase the risk for certain diseases, while unsaturated fats do just the opposite. So, the basic message is simple: limit your intake of saturated fats and increase your intake of unsaturated fats.