Ahead of World Heart Day on 29 September, Dietitian Kate Save (pictured) is urging the supplement sector to look past the milligrams of oil printed on the front of the pack and to scrutinise what an omega-3 ingredient actually delivers.
Save, founder and CEO of Be Fit Food, says the conversation needs to move beyond simply taking an omega-3 supplement to understanding the type, its delivery form and how effectively the body can use it.
She is partnering with Aker BioMarine on an educational omega-3 campaign.
Why does omega-3 form matter?
Krill oil and conventional fish oil both provide the long-chain omega-3 fatty acids EPA and DHA. The difference, Save says, is the molecular form in which they are carried.
Much of the EPA and DHA in krill oil is naturally bound to phospholipids, the structural components of cell membranes.
Fish oils typically deliver omega-3s predominantly as triglycerides or ethyl esters.
Unlike conventional fish oil, krill oil delivers omega-3s in phospholipid form, the same building blocks found in the body's own cells.
Save added that this may make them easier to absorb and use.
What does the evidence say about absorption?
Save points to a 2024 network meta-analysis of 26 studies comparing omega-3 bioavailability from fish oil and krill oil.
It found superior absorption from krill oil at doses under 2000mg, with the highest area-under-the-curve values seen in a krill oil phospholipid/free-fatty-acid formulation.
A smaller 2015 human crossover study in healthy adults, at roughly equivalent EPA and DHA doses, found significantly greater 72-hour incorporation into plasma phospholipids after krill oil than after fish oil.
Save cautioned that bioavailability is also shaped by formulation, dose and how the omega-3 is consumed.
Whole foods, she stressed, remain the foundation: oily fish such as salmon, sardines, mackerel and trout provide EPA and DHA alongside protein, vitamin D, vitamin B12, iodine and selenium.
Plant sources such as chia, flaxseed and walnuts supply ALA, but conversion to EPA and particularly DHA is limited.
What does the triglyceride research show?
EPA and DHA are well established for lowering triglycerides and are involved in pathways that regulate inflammation.
A randomised clinical trial published in JAMA Network Open in 2022 tested a krill-derived omega-3 formulation in 520 adults with severe hypertriglyceridaemia.
After 12 weeks, triglycerides fell by 26% in the krill group versus 15.1% with placebo, a treatment difference of 10.9 percentage points.
Save notes the effect persisted at 26 weeks.
She did also flag limitations: the findings are most directly relevant to people with severe hypertriglyceridaemia and to that specific formulation, so they should be read alongside the broader EPA and DHA evidence.
What should formulators ask about provenance?
Beyond EPA and DHA content and form, Save says formulators should prioritise product stability, purity and dose consistency, as well as pressing suppliers on sourcing.
"Sustainability shouldn't simply be a claim on a label," she said, adding that brands should ask where an ingredient comes from, how the fishery is managed, what independent oversight exists and whether the supplier can show traceability to source.
Save cites Antarctic krill as an example.
The UN Food and Agriculture Organization's latest assessment found 100 per cent of assessed stocks in Antarctic waters were biologically sustainable and the fishery is managed internationally by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) under a precautionary, ecosystem-based approach.
A broader cardiometabolic picture
Save also cautioned against viewing triglycerides in isolation. Elevated levels often occur alongside insulin resistance, central adiposity and chronic low-grade inflammation, all of which contribute to cardiovascular risk.
For people with raised triglycerides or existing cardiovascular disease, supplementation should form part of a wider conversation with a healthcare professional about diet, lifestyle and management.
World Heart Day is a useful reminder that cardiovascular risk is rarely about one number.
