EPA (eicosapentaenoic acid) and/or DHA (docosahexaenoic acid) are present in the oils derived from wild-catch deep-sea fish, other marine animals and algae. Fish acquire their EPA/DHA omega-3s from consuming algae or other animals that eat algae. EPA/DHA omega-3s are not present in vegetable oils including flax seed oil, which may be rich in the plant-sourced omega-3, alphalinolenic acid (ALA).

Omega-3 fatty acids are recognised as ‘essential’ in the diet for the maintenance of good health as humans and all animals are unable to synthesise them.  Western diets are deficient in EPA/DHA, consequently the EPA/DHA supplements industry has boomed with rising public awareness of the health benefits of dietary supplementation.

Vegans and many vegetarians choose to consume ALA because they will not or choose not to eat fish products. ALA converts to EPA at very low efficiency in women but generally not in men.

Dietary deficiencies induced by our modern industrialised lifestyle are known to cause several diseases and abnormalities.  Consequently, supplements are used to prevent an increasing number of diseases such as neural tube defects in in unborn children with folic acid.

However, according to a Harvard School of Public Health study, dietary deficiency in EPA and DHA omega-3s may be even more widespread in its prevalence and more devastating in its consequences.

EPA and DHA Omega-3 oils are recognised as vital functional food ingredients delivering significant health benefits.  Supplementation with EPA and/or DHA omega-3 is increasingly associated with the following reported benefits arising from reversing dietary EPA/DHA deficiency:

• Reduces risk of heart disease
• Reduces risk of depression & onset of schizophrenia
• Lowers risk of type 2 diabetes
• Slows tumour growth
• Improves infant & child health
• Improves bone health and muscle strength in the elderly
• Reduces effect of autoimmune diseases – e.g. rheumatoid arthritis
• May delay or prevent Alzheimer’s disease and other cognitive impairment disorders

The rapidly growing global acceptance of the health benefits of EPA and DHA oils can be ascribed to the large quantity of scientific evidence which has fuelled the increasing demand for omega-3 oils and functional foods that contain them.

Heart Disease

The role of EPA and DHA omega-3 fatty acids in cardiovascular disease is well established in reducing elevated triglyceride levels, slightly raising the levels of HDL – i.e. “good” cholesterol, reducing blood homocysteine levels, reducing blood pressure and “thinning” the blood. High levels of omega-3 in the blood have been associated with reduced risk of cardiovascular disease and related mortality. They also appear to slow the development of atherosclerotic plaques and blood clots, and may be beneficial during recovery from heart attack. However, studies suggest that any beneficial effects of supplemental omega-3 may be masked by the continuance of other heart medications or high consumption of fish.

Diabetes

Omega-3 fatty acids from fish oil can help lower triglycerides and apoproteins (markers of diabetes), and raise HDL in the blood, so taking EPA and DHA may help people with diabetes.

The incidence of diabetic retinopathy may be significantly reduced by increasing the consumption of EPA and DHA omega-3.

Arthritis

The anti-inflammatory effects of EPA and DHA omega-3s may inhibit inflammatory process associated with several diseases.

Rheumatoid arthritis (RA) is an autoimmune disease that causes inflammation in the joints. A number of studies suggest that EPA and DHA supplementation helps to reduce symptoms of RA, including joint pain and morning stiffness, with considerable success especially in the early stages of the disease. In contrast , there is insufficient evidence supporting the use of omega-3s in reducing the pain and stiffness of osteoarthritis.

Studies suggest that the painful joint inflammation caused by gout may be inhibited by EPA and DHA.

Systemic Lupus Erythematosus (SLE)

Lupus is an autoimmune disease characterised by fatigue and joint pain. Several studies suggest that EPA and DHA fish oil may help reduce the symptoms of lupus.

Mental Illness

Many studies have shown that people who took high doses of omega-3 fatty acids in addition to prescription antidepressants had a greater improvement in symptoms than those who took antidepressants alone, but some have not. Cases of major and moderate depression appear to respond best to omega-3 supplementation and a positive response may be associated more with EPA than DHA dosage.

Depression in the elderly may be associated with very low EPA levels, which can be restored with EPA supplementation. There is also published evidence that unmedicated young adults with mild to moderate depression reported they were no longer depressed after taking EPA and DHA.

Low blood levels of omega-3s, particularly DHA are more common in military personnel that commit suicide than those that do not.  The researchers
noted that omega-3 fatty acid levels were generally low in studied military personnel compared with the general population, and suggested that omega-3 supplementation may reduce the alarming rate of suicide. research in this area is ongoing. 

Studies have suggested that people with bipolar disorder who took EPA and DHA in addition to standard prescription treatments for bipolar disorder for 4 months experienced fewer mood swings and relapse than those who received placebo.

Recent reports suggest that adolescents and young adults at risk of developing psychosis or schizophrenia are less likely to progress into a psychotic disorder when they take EPA and DHA supplements. The observed response appears to be less in older age groups, suggesting that omega-3 supplementation may be more effective when the brain is still developing.

Acne

One study has reported that omega-3 supplementation significantly reduced the severity of acne in young adult men and women.

Attention Deficit Hyperactivity Disorder (ADHD)

ADHD affects about 10 million children in the United States. Children with ADHD often have low levels of DHA, which may trigger learning and behavioural problems. Recent research findings indicate that an increased red blood cell level of DHA is associated with improved reading, spelling and lower parent ratings of oppositional behaviour, hyperactivity and restlessness.

Cognitive and Mobility Decline

A recent study  of elderly persons who were free of dementia suggests that blood levels of a protein related to Alzheimer’s disease and memory problems are lowered by consuming more omega-3 fatty acids but only when vitamin B levels are adequate. In persons over 65 with mild cognitive impairment, high doses of  DHA together with EPA showed improvement that may be associated with reduction in depressive symptoms, which may reduce the risk of developing dementia.

There is evidence that persons with low blood levels of DHA and EPA show improved memory performance six months after starting high-dose omega-3 supplementation.

During healthy ageing, muscle size is reduced by 0.5-2% per year. This process – known as sarcopenia – can result in frailty and immobility in older people. A 2012 trial showed that women aged over 65 who received omega-3 fatty acids gained almost twice as much muscle strength following exercise than those taking olive oil.

Asthma & Eczema

A study reported in 2012 of 700 pregnancies showed that when their mothers consumed EPA and DHA omega-3 oil the risk of infants developing eczema was reduced by 36%, sensitisation to eggs by 38% and egg allergy by 50%. A study published in 2016 found that EPA and DHA supplementation of pregnant mothers decreased the incidence of asthma in their offspring.

Macular Degeneration

A questionnaire given to more than 3,000 people over the age of 49 found that those who ate more fish were less likely to have macular degeneration (a serious age related eye condition that can progress to blindness) than those who ate less fish. Similarly, a clinical study comparing 350 people with macular degeneration to 500 without the eye disease found that those with a healthy dietary balance of omega-3 and omega-6 fatty acids and more fish in their diets were less likely to have macular degeneration.

Cancer

Eating foods rich in omega-3 fatty acids seems to reduce the risk of colorectal cancer. For example, Eskimos, who tend to have a high fat diet, but eat significant amounts of fish rich in omega-3 fatty acids, have a low rate of colorectal cancer. Animal studies and laboratory studies have found that omega-3 fatty acids prevent worsening of colon cancer.

Fish consumption and EPA and DHA supplementation are associated with a lower risk of recurrence and death from breast cancer. The natural anti-inflammatory effects of DHA and EPA are postulated to be the cause of this anti-cancer effect.

There have been mixed reports as to whether DHA and EPA omega-3s help to prevent prostate cancer. However, countries that traditionally consume large amounts of fish, such as Japan, have very low incidences of prostate cancer.

Inflammation and Muscle Pain After Exercise

There are reports that daily EPA and DHA supplementation may significantly reduce muscle the pain of muscle damage and inflammation after exercise.

Chemotherapy

Supplementation with EPA and DHA omega-3 during cancer chemotherapy may prevent weight loss.

Media Reports on Omega-3

Useful Links:

• Omega-3 fact sheet – US National Institutes of Health
• Why omega-3s?
• Algal DHA is equivalent to fish DHA
• Mental Health, Cognition and Omega-3s: What do we know?
• Omega-3 & pregnancy
• Omega-3 & aging
• Australian omega-3 guidelines
• Recent medical research on omega-3
• Omega-3 FAQ