Fish oil supplements Vs eating fish: Which is better for health?

Fish oil, which contains omega-3 fatty acids, is promoted for a number of health benefits – from boosting our heart health, protecting our brain from dementia, and easing the symptoms of rheumatoid arthritis.

But what exactly are omega-3 fats and what does the evidence say about their benefits for keeping us healthy? And if they are good for us, does eating fish provide the same benefit as supplements?

What are omega-3 fats?

Omega-3 fatty acids are a type of polyunsaturated fatty acid. They are essential to consume in our diet because we can’t make them in our body.

Three main types of omega-3 fats are important in our diet:

• Alpha-linolenic acid (ALA), which is found in plant foods such as green leafy vegetables, walnuts, flaxseed and chia seeds

• Eicosapentanoic acid (EPA), which is only found in seafood, eggs (higher in free-range rather than cage eggs) and breast milk

• Docosahexaenoic acid (DHA) is also only found in seafood, eggs (again, higher in free-range eggs) and breast milk.

Omega 3s are key to the structure of our cells, and help keep our heart, lungs, blood vessels, and immune system working.

Eating fish vs taking a supplement

The initial studies suggesting omega-3 fats may have health benefits came from observational studies on people eating fish, not from fish oil. So are the “active ingredients” from supplements – the EPA and DHA – absorbed into our body in the same way as fish?

An intervention study (where one group was given fish and one group fish oil supplements) found the levels of EPA and DHA in your body increase in a similar way when you consume equal amounts of them from either fish or fish oil.

Raw salmon in paper

Eating fish might have other benefits that supplements can’t give. Unsplash/CA Creative

But this assumes it is just the omega-3 fats that provide health benefits. There are other components of fish, such as protein, vitamins A and D, iodine, and selenium that could be wholly or jointly responsible for the health benefits.

The health benefits seen may also be partially due to the absence of certain nutrients that would have otherwise been consumed from other types of meat (red meat and processed meat) such as saturated fats and salt. So what are the benefits of omega 3 fats? And does the source matter?

Let’s consider the evidence for heart disease, arthritis and dementia.

Heart disease

For cardiovascular disease (heart attacks and stroke), a meta-analysis, which provides the highest quality evidence, has shown fish oil supplementation probably makes little or no difference.

Another meta-analysis found for every 20 grams per day of fish consumed it reduced the risk of coronary heart disease by 4 per cent.

The National Heart Foundation recommends, based on the scientific evidence, eating fish rich in omega-3 fats for optimal heart health. Fish vary in their omega-3 levels and generally the fishier they taste the more omega-3 fats they have – such as tuna, salmon, deep sea perch, trevally, mackeral and snook. The foundation says fish oil may be beneficial for people with heart failure or high triglycerides, a type of fat that circulates in the blood that increases the risk of heart disease and stroke. But it doesn’t recommend fish oil for reducing the risk of cardiovascular diseases (heart attack and stroke).

(The author is Program Director of Nutrition and Food Sciences, Accredited Practising Dietitian, University of South Australia)