It’s all a bit fishy
While there is no danger in downing over-the-counter fish oil, it seems there are more delicious ways to up your omega-3s, writes Stephen Heard.
The basics
It’s oil extracted from fish – or by pressing, steaming and boiling down the fatty tissue of coldwater species like salmon, anchovies, herring and mackerel. Omega-3 is the headlining fatty acid of fish oil and something which is considered to be essential for good health, particularly for the prevention of heart disease. Humans don’t naturally produce the fatty acids so they must be absorbed through what we eat.
Taking over-the-counter fish oil supplements, in capsule and gel form, is the most popular method to access the long chain omega-3 fats EPA and DHA. Several questions remain about the efficacy of fish oil supplements for improving health and whether or not an easier option would just be eating more oily fish.
Why it’s so popular
Before the creation of synthetic vitamins and supplements, grandparents everywhere were downing nauseating cod liver oil by the spoonful.
The mainstream fish oil supplement trend arose in the early 1970s when Danish researchers discovered that native Greenland Inuit had low rates of heart disease despite consuming large amounts of fats by way of the deep blue sea.
Miracle fish oil pills hit the shelves, claiming to improve heart health, support brain and liver function, reduce the effects of arthritis, curtail depression and lower the chance of cancer.
In New Zealand, a 2018 crosssectional survey questioning 334 residents revealed that fish oil was taken by around 22 per cent of respondents, with close to 73 per cent taking the dietary supplements for general wellbeing and more than 50 per cent to improve brain function.
What the experts are saying
Fish oil dietary supplements and their purported health benefits have attracted plenty of scientific scrutiny. On life sciences search engine PubMed you’ll find upwards of 7000 papers listed under ‘‘fish oil supplements’’. It’s all a bit fishy.
In 2015 researchers from the University of Auckland’s Liggins Institute found that almost all of the fish oil supplements available in New Zealand at the time contained lower concentrations of fatty acids than what was printed on the label. A similar study published by the New Zealand Medical Journal in 2019 analysing New Zealand fish oil supplements was retracted after calculation errors were found with the omega-3 test results.
The earlier Liggins study also found that the majority of fish oils tested exceeded the recommended levels of oxidisation, which decreases the performance of the suggested active compounds. By comparison, a 2016 review found Australian and New Zealand fish oil products clearly meet their label claims and are not oxidised.
Most recently, Liggins researchers found that fresh fish oil given to overweight pregnant rats prevented their offspring from developing a major diabetes risk factor. The institute is currently recruiting for a human pregnancy study, as part of a series looking at the potential of fish oil to reduce the risk of diabetes and other obesity-related illnesses.
Elsewhere, evidence-based health database Cochrane Library published a review in July 2018 showing there is little or no effect of omega-3 supplements on the risk of experiencing heart disease, stroke or death. The review measured more than 100,000 people across five years.
Fish oil is good for what?
While there is no danger in consuming the recommended dose of over-the-counter fish oil, it seems there are more delicious ways to up your omega-3s and lower ‘‘bad cholesterol’’ and triglycerides. It’s as simple as eating oily fish like salmon or sardines.
For those who don’t eat fish or perhaps are allergic to seafood, sources of the alpha-linolenic (ALA) omega-3 – not found in fish – come from the likes of flaxseed oil, chia seeds, kiwifruit, walnuts and hemp. A plant-based option which is better for the balance of marine life.