Omega 3 is a classification of polyunsaturated fatty acids (PUFA’s) (good or healthy fats) known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are known as ‘Essential Fatty Acids’ or EFA’S and this is because these types of fat cannot be manufactured by the body and must be obtained through diet. EFA’s are found in oily fish, flaxseeds, nuts and seeds. There is no official Recommended Daily Amount (RDA) for omega 3 although dosage ranges between 1-3g per day.
Fats are our main source of energy and insulation. Omega 3 provides flexibility and stability to the cell walls which supports the transportation of nutrients and hormones around the body. Omega 3 is involved in regulating blood pressure, blood clotting, inflammation, nerve transmission and the synthesis of hormones amongst many other functions.
Deficiency of essential fatty acids is associated with rough, scaly skin and dermatitis. Other signs and symptoms include; fatigue, lack of endurance, dry skin, cracked nails, dry, lifeless hair, gastrointestinal issues such as gas and bloating, maldigestion and constipation. A deficiency is also associated with depression, frequent colds and infections, arthritis, cognitive impairment, and aching joints. A lack of essential fatty acids has also been associated with the development of many chronic degenerative diseases such as heart disease, cancer and strokes.
Cardiovascular Health– Strong evidence exists to support the role of omega 3 PUFA’s in cardiovascular health. An analysis of 25 studies found that tissue concentrations of omega 3 PUFA’s, specifically docosahexaenoic acid (DHA) were significantly associated with risk for coronary heart disease (1). The DART study, involving 2,033 men who had experienced recent heart attack found that supplementing with omega 3 fish oil resulted in a 29% reduction in mortality, specifically from coronary heart disease (2). The GISSI study involving 11,323 post-heart-attack patients found that supplementing with 1000mg fish oil significantly reduced the cardiovascular risk resulting in a decreased risk of death by 20% and cardiovascular death by 30% after 1 year (3). Similar benefits were reported in the study at 3 years follow up (4). Furthermore, a meta-analysis of 7 studies involving 825 patients concluded that fish oils significantly improved cardiovascular function in patients with non-ischaemic heart failure (5). Their protective actions have been linked to their anti-inflammatory effects (6) and the positive impact upon cell communication in cardiovascular disease (7). Based upon the evidence to support the role of omega 3 PUFA’s in relation to cardiovascular health, the EU Commission Regulation Panel, 2012 (8) conclude that a cause and effect relationship has been established between the consumption of EPA and DHA and maintenance of normal cardiac function.
Cholesterol– Omega 3 PUFA’s have also been shown to support cardiovascular health in relation to their effect on blood triglycerides and cholesterol concentrations. Supplementation with fish oil at a dose of 1.7g/d EPA and 1.2g/d DHA for 6 weeks reduced serum triglycerides and increased HDL (good) cholesterol concentrations in 28 overweight and obese patients (9). The role of EPA and DHA and blood concentrations of triglycerides has been under review by the EU Commission Regulation, 2012 (8) in order to support the claim that EPA and DHA contribute to the maintenance of normal blood fasting concentrations of triglycerides.
Cognitive function and mental health – Deficiency of omega 3 PUFA’s have been associated with a wide range of mental health disorders. Omega 3 PUFA’s make up a significant proportion of the lipid fraction of the human brain and play important roles in neurological functions including the maintenance of neuronal membranes, neurotransmission, maintenance of membrane fluidity and flexibility and modulation of ion channels and cellular receptors (10). The importance of omega 3 in cognition is demonstrated by its positive association with increased blood flow in the brain during cognitive tasks (11), cognitive performance and memory (12). Several double-blind randomized trials have suggested omega 3 from fish oils may benefit attention-deficit/ hyperactivity disorder, anxiety, autism, childhood depression, dyspraxia, dyslexia, aggression, bipolar disorder, schizophrenia, borderline personality disorder, mild cognitive impairment and dementia (14) however the most robust evidence to date relates to mood and anxiety, in particular, major depressive disorder. A systematic review of 21 clinical trials found an antidepressant effect with omega 3 PUFA (EPA or DHA alone or in combination) supplementation (15). A further meta-analysis of 10 clinical studies in 2007 found a significant antidepressant effect of omega 3 PUFA’s in patients with depression or with bipolar disorder. In 2006 a further meta-analysis reported significant antidepressant effects in uni bipolar and bipolar depression with omega 3 PUFA supplementation (16).
Skin Health (Psoriasis, Eczema and Acne)-Research has also found a correlation between omega 3 intake and skin health. EPA has been shown to improve psoriasis (17). Intake of omega 3 PUFA during pregnancy has also been shown to reduce the risk of food allergies and eczema in children at 18 months (18). There is also evidence to suggest EPA and DHA may reduce damage caused by UV light and inflammation in skin cells (19) and also benefit acne (20).
Arthritis- The role of omega 3 PUFA’s in inflammation has been demonstrated in numerous studies. Fish oil exerts anti-inflammatory actions in arthritis (21). A summary of 18 trials showed reductions in tenderness and stiffness in rheumatoid arthritis when treated daily with fish oil (22). A further robust meta-analysis showed reduced pain symptoms in Rheumatoid Arthritis (23).
High Blood Pressure– DHA and EPA contribute to the maintenance of normal blood pressure. EPA and DHA contribute to the normal function of the heart. Due to its potential blood thinning action omega 3 fatty acids EPA and DHA may help to reduce high blood pressure and therefore may be a valuable supplement for those suffering from hypertension.
Lower the risk of heart attack and stroke– DHA and EPA contribute to the maintenance of normal blood triglyceride levels. Omega 3 fatty acids help reduce harmful cholesterol and triglycerides which help to reduce the risk of heart attacks and strokes.
Arthritis- Omega 3 may be beneficial for those suffering from arthritis due to the anti-inflammatory properties of these fatty acids.
Brain Health– Due to the widely researched role of omega 3 in brain health, a supplement may be beneficial for those looking to improve cognitive function including memory and concentration and for those with depression and/or anxiety.
Skin- Omega 3 is important for the health of the skin. Omega 3 has been shown to improve skin conditions such as psoriasis, eczema and acne and so a supplement may be useful for anyone looking to address these skin conditions.
Side effects of omega-3 supplements are usually mild and can include; unpleasant taste, bad breath, heartburn, nausea, gastrointestinal discomfort, diarrhoea and headaches. Whilst no Tolerable Upper Intake Level has been officially established, long term combined doses of EPA and DHA of up to according to 5g per day appears to be safe according to the European Food Safety Authority. Omega 3 has been reported to have blood thinning properties and so should be used with precaution by those taking blood thinning medications.