The two most important omega-3s are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). You will find them mostly in oily fish such as salmon and sardines. Another type of omega-3 fatty acid is called alpha-linolenic acid (ALA), which is found in plant foods such as walnuts, soybeans and flaxseeds. The body can convert a small amount of ALA into EPA and DHA.

Omega-3 fatty acids are important parts of the structure of cell walls. They are found abundantly in the eyes and brain, and this links to their key role in development and vision, especially in the early stages of life. Low levels of omega-3s during pregnancy are associated with preterm birth and potentially delayed cognitive development. In older adults, people who have higher amounts of omega-3s in their diet have a lower risk of developing a disease that affects the eye called age-related macular degeneration.

Omega-3s also have a crucial role in helping to keep the heart and blood vessels healthy and the immune system working normally. A diet rich in foods high in omega-3 fatty acids is linked with a decreased risk of heart disease. Regular consumption of foods high in omega-3 fatty acids may help to prevent blood clots, protect against irregular heartbeats, improve blood lipids and lower blood pressure.

Just like omega-3s, omega-6 fatty acids are also essential fatty acids with the main two of interest being linoleic acid (LA) and arachidonic acid (AA). The typical western diet is rich in omega-6s where LA dominates given its presence in vegetable oils such as sunflower, soybean, corn and canola oils. Foods derived from animals such as meat and eggs are the main dietary sources of AA plus our bodies can also make AA from LA. Hence, we use AA as the benchmark for understanding the amount of omega-6s in your diet.

Omega-6 fatty acids have more of a counterbalancing action to omega-3s. They can promote inflammation, blood clotting, and the constriction of blood vessels. But it is too simplistic to say that omega-3s are ‘good’ and omega-6s are ‘bad’. A balance between the two is needed for good health and omega-6s are just as important for healthy brain development, heart health and a robust immune system.

Omega-3 fatty acids are essential which means they need to be consumed in the diet. Knowing that omega-3s play important roles in brain development, immune function, vision, and blood and heart health gives a clear picture of the consequences of not having enough omega-3s

An overt deficiency of omega-3s in people in Australia is quite rare as most diets meet the minimum amount needed. Many research studies are exploring the role of omega-3s in chronic health problems such as heart disease and inflammation and the potential risk that sub-optimal intake of omega-3s in your diet might play in your health.

A deficiency of omega-3s can present as changes in the skin. Omega-3s are important for the integrity of our skin barrier and preventing the loss of moisture. Dry, sensitive and inflamed skin can be the result of deficiency. Dry, dull or brittle hair or even brittle nails are also seen with a deficiency of omega-3s.

Omega-3s play an important role in eye health and symptoms such as dry eyes have been linked to omega-3 deficiency in early research studies. That is because omega-3s are important in maintaining eye moisture.

Omega-3 fatty acids are essential parts of the brain and are known to have neuroprotective and anti-inflammatory effects. Poor memory, mood changes, anxiety and even depression have all been linked to a deficiency of omega-3s.

Then there are problems such as joint pain arising from degradation and inflammation of tissues and joints. This relates to the protective anti-inflammatory role that omega-3s have.

A deficiency of omega-3 fatty acids can present in different ways. Common signs and symptoms include:

• Dry, rough and scaly skin
• Dermatitis (inflamed skin)
• Changes in attention span, mood and memory
• Brittle nails
• Depression
• Joint pain and weakness
• Slow wound repair
• Fatigue

A deficiency of omega-3 fatty acids can have many causes. Common risk factors include:

• Following a very low-fat diet
• Chronic malnutrition: poor nutrition that leads to a long term condition, stunting growth
• Pancreatic insufficiency: where the body doesn’t make enough enzymes to digest food
• Cystic fibrosis: that causes severe damage to the lungs and digestive system
• Inflammatory bowel disease: a group of disorders that cause inflammation of the digestive tract

It is said you are what you eat, and for omega fatty acids, that is especially true. As your diet changes, so too do the levels of omega fatty acids in your body.

The best dietary sources of the long-chain omega-3s of EPA and DHA are from seafood. The Heart Foundation recommends eating two to three servings of fish per week as part of a heart-healthy diet. Fish with the highest amounts of omega-3s include salmon, blue-eye trevalla, blue mackerel, herring, canned sardines, canned salmon and some varieties of canned tuna. Other good sources of marine-sourced omega-3s include barramundi, bream, flathead, squid, scallops and mussels.

The body can make a small amount of EPA and DHA from the omega-3 fatty acids found in plant foods such as walnuts, flaxseeds, chia seeds and oils such as canola and soybean. For someone following a vegetarian diet and not wishing to eat fish, then having more of these types of foods will help with omega-3 levels.

Omega-6 fatty acids are also an important part of the diet. And while too many omega-6s compared to omega-3s can be a problem, in Australia, it is more of an issue of the types of foods that are high in omega-6s that is the concern. Highly processed foods such as take-away foods, snacks and desserts are all major contributors to omega-6 intake so eating less of these will be better for overall health. Better food sources of omega-6s include walnuts, soy foods, seeds, eggs and almonds.

Most Australians get enough omega-6 fats in their diet, so it is better to focus on increasing how much seafood and other sources of omega-3 fats you eat.