Omega-3 : Many thanks to the ABC who printed the original

Omega-3: What are the health benefits and how should you eat it?

Omega-3. You've seen the word (and number) splashed across cereal boxes, tins of tuna and one of Australia's most popular supplements: fish oil.

These famous fatty acids are thought to have a vast range of health benefits.

So how can you make the most of them?

Omega-3 is short for omega-3 polyunsaturated fatty acids. They're a family of "essential fats" that play an important role in the way our cell membranes work.

Fats tend to get a bad rap, but polyunsaturated fats are the good guys. They help keep cholesterol balance in your body, decreasing the bad cholesterol and increasing the good cholesterol.

When it comes to the health benefits of omega-3, here's what you need to know.

The strongest evidence for the benefits of omega-3 fats comes from studies of heart disease.

Research shows people who regularly consume fish (the best source of omega-3) tend to have lower rates of heart disease and stroke — and that may well be down to omega-3.

These fats are known to help lower your heart rate, reduce the risk of clotting, lower triglycerides, decrease blood pressure, improve blood vessel function and delay the build-up of plaque in coronary arteries.

"Omega-3 fatty acids cut down the blood fat — blood cholesterol and blood triglycerides — and they also cut down inflammation in the body. These are the two underlying causes of cardiovascular disease," Professor Garg says.

Those anti-inflammatory properties of omega-3 have been used to help people with rheumatoid arthritis and diabetes.

High-fish diet recommended

While omega-3 fats can be found in plants, seafood, and to a lesser extent, eggs and meat, the best way to boost your intake of fatty acids is to increase the amount of oily fish you consume.

The Heart Foundation recommends including two to three serves of fish (with the skin on) in your diet each week (150 grams per serve), as well as one gram of plant-sourced omega-3 fats each day.

"When eating or preparing fish, choose cooking methods such as steaming, grilling, light pan-frying, baking, barbequing or even raw fish such as sushi or sashimi," the Heart Foundation says.

"You can add fish to stir-fries, casseroles, pasta and soups, or simply have it in a sandwich or in a salad."

Good sources of marine omega-3s include salmon, blue-eye trevalla, blue mackerel, herring, canned sardines, canned salmon and some varieties of canned tuna.

When it comes to plant sources, walnuts, linseed, chia seeds, pumpkin seeds, tofu, leafy greens and vegetable oils such as canola and soybean are all good options.

Vegetarian alternatives on the horizon

If you don't eat fish, it's important to maximise your intake of plant-based sources of omega-3.

However, the type of omega-3 fatty acid found in plants (alpha-linolenic acid) is nowhere near as effective as the types found in marine sources (docosahexaenoic acid and eicosapentaenoic acid).

"From the plant sources, we do not get the fatty acids which are present in our body — we only get the precursors of those omega-3 fatty acids," Professor Garg says.

"So, they're not readymade … our body has to work hard, and the conversion of plant omega-3 fatty acids into docosahexaenoic acid is extremely slow.

"The conversion rate is almost less than 1 per cent."

Look for tuna canned in springwater or extra virgin olive oil. And try not to drain the oil out — it helps to retain omega-3.

Given the modest conversion rate, the Heart Foundation says it's important vegetarians and vegans still include marine-sourced omega-3 fats in their diet.

Little evidence for supplements

While some research shows fish oil supplements may help to reduce triglycerides in your blood, it's unclear whether they reduce your risk of cardiovascular disease.

Recent studies suggest the supplements may not be as helpful as previously thought in reducing the risk of heart attack or stroke.

Easy ways to eat healthy fats

Include 2–3 serves of fish a week (100–150g per serve).

Use nuts and seeds in your breakfast. Sprinkle ground linseed on cereal or try a handful of almonds sprinkled over yoghurt.

A handful of unsalted nuts make a healthy snack any time of the day.

Use oils and margarine spreads made from olive, sunflower, canola and safflower oils in cooking and on sandwiches and toast instead of butter.

Choose wholegrain bread with linseeds.