Omega-3 Fatty Acids
Omega-3 fatty acids are essential fatty acids that humans need for their cell membranes and various physiological and biological processes. Omega-3 refers to the chemical make up of these fatty acids. Omega-3 fatty acids are essential fatty acids, meaning that they cannot be synthesised by the human body and therefore must be supplied by our diet. Omega-3 fatty acids can occur in plant sources (ALA alpha-linolenic acid) such as flaxseed, walnuts, chia seeds and their oils, and canola, and soybean oil. Omega-3 fatty acids are also found in marine sources: EPA eicosapentaenoic acid, DPA docosapentaenoic acid, and DHA docosahexaenoic acid. Marine sources include salmon, sardines, herring, mackerel, tuna, trevally, kahawai, oysters, green muscles, and fish and algal oil supplements. Poultry and meat also contribute to omega-3 intake.
To date a large amount of research has been carried out into the beneficial effects of consuming omega-3 fatty acids in our diet. Health benefits are wide-ranging and include mental health, heart health, neurodevelopment, cognitive health, bone health, eye health, and inflammatory conditions.
At a recent symposium on omega-3 fatty acids held by the Institute of Food, Nutrition, and Human Health at Massey University, the health benefits of omega-3 fatty acids were discussed.
Symposium Findings:
- Controlled treatment trials with dietary supplementation of omega-3 fatty acids has shown benefits in children with ADHD (Attention Deficit Hyperactivity Disorder) and/or related behavioural and learning difficulties (e.g., dyslexia, dyspraxia, and autism).
- Healthy adults with a diet low in omega-3 fatty acids, showed improved memory and speed of memory when their diet was supplemented with a high dose DHA supplement for 6 months.
- Studies in elderly people demonstrate that benefits from omega-3 supplementation are more pronounced in elderly people that are in early stages of cognitive impairment.
- A number of studies have shown that omega-3 supplementation is beneficial for depression in elderly people; depression is a risk factor for progression to dementia.
- The omega-3 acids EPA and DHA have been shown to significantly reduce the risk of fatal coronary heart disease and sudden cardiac death. EPA and DHA show consistent and established lowering of triglyceride concentrations.
- Omega-3 fatty acids seem to have a protective effect on bone especially post-menopause. However more studies need to be carried out as the data is inconclusive.
- The New Zealand population may be at risk of not consuming enough fish/seafood and therefore not consuming enough omega-3 fatty acids. The latest New Zealand Adult Nutrition Survey showed that almost 30% of the total population aged 15 years and over never consumed or did not consume fresh or frozen seafood in the past four weeks. Figures for canned seafood indicated that 42% of the population never consumed or did not consume canned seafood in the past four weeks. People not consuming fish/seafood should consider taking supplements.
- The omega-3 oil industry is growing in the global market and there are some concerns regarding sustainability. Omega-3 oils are mostly sourced from fish oils obtained as a by-product of the fish meal industry. Alternative sources of EPA and DHA include krill, micro-algea, and genetically modified plants.
- The quality of fish oils available in shops can be difficult to determine. The NZ Consumers Institute recommends against buying supplements nearing their best before date. Supplements should be stored away from light and preferably in the fridge. So look for retailers who store their product away from fluorescent lighting and in the fridge. Don’t rely on the total fish oil per capsule claims; instead look for the total omega-3 content.
- The GOED (Global Organization for EPA and DHA Omega-3) website has a list of members to their organisation that have signed an affidavit that they will manufacture products to a quality standard that is stricter than any regulation in the world.