Omega-3 and cardiovascular health

Discover how EPA & DHA omega-3s support heart health.

Cardiovascular disease remains the second leading cause of death in Australia, responsible for roughly one in four deaths each year. Nutrition is one of several modifiable risk factors, and among dietary components, omega-3 fatty acids have attracted decades of scientific attention for their relationship with cardiovascular wellbeing.

EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the long chain omega-3s found primarily in oily fish and fish oil, are involved in multiple pathways that influence heart and blood vessel function. This article explores what the research shows about omega-3 and cardiovascular health, how EPA and DHA contribute differently, where most Australians stand on intake, and what to consider when choosing a supplement.

Understanding cardiovascular health and the role of nutrition

The cardiovascular system is a network of the heart, blood vessels and blood that delivers oxygen and nutrients to every tissue in the body. When this system functions well, blood flows freely, vessel walls remain flexible, and the heart pumps efficiently. When it doesn’t, the consequences range from elevated blood pressure and abnormal blood lipids to more serious outcomes over time.

According to the Australian Institute of Health and Welfare, an estimated 1.3 million Australian adults were living with one or more conditions related to heart, stroke or vascular disease in 2022. Dietary risks contributed to 32% of the total cardiovascular disease burden in 2024, making nutrition one of the most significant modifiable factors alongside blood pressure and cholesterol management.

This is where omega-3 fatty acids enter the picture. EPA and DHA are not a single solution to cardiovascular risk, but they are among the most extensively researched dietary components in the cardiovascular field. Their influence spans several of the biological processes that contribute to heart and blood vessel function.

How omega-3 supports heart function and circulation

EPA and DHA influence cardiovascular health through multiple overlapping mechanisms. A 2025 review published in Current Atherosclerosis Reports synthesised evidence from 2020 to 2025 and identified several key pathways through which these fatty acids contribute to cardiovascular function.

Blood lipid metabolism

EPA and DHA play a role in the maintenance of healthy blood lipid levels. They are involved in hepatic fatty acid metabolism and the clearance of triglyceride rich lipoproteins from the bloodstream. A 2025 dose response meta-analysis in Food Science & Nutrition examined 20 reports involving 1,685 participants with coronary heart disease and found that omega-3 supplementation was associated with reduced circulating triglyceride levels and total cholesterol levels compared to control groups.

Inflammatory regulation

Low grade inflammation is recognised as a contributor to the development of atherosclerosis, the process by which plaque builds up in arterial walls. EPA and DHA are precursors to specialised pro-resolving mediators, a class of molecules involved in dampening inflammatory responses. EPA appears to play a particularly active role in modulating inflammatory markers, which may partly explain its prominence in cardiovascular research.

Blood vessel function

The endothelium, the thin lining of blood vessels, plays a central role in regulating blood flow, clotting and vascular tone. A 2024 GRADE assessed systematic review and meta-analysis in the European Journal of Clinical Investigation examined randomised controlled trials and found that omega-3 supplementation was associated with improvements in endothelial function, as measured by flow-mediated dilation.

Heart rhythm and autonomic function

Emerging evidence points to EPA and DHA influencing cardiac ion channels and autonomic nervous system function via vagal tone. These pathways may contribute to heart rhythm stability, though this area of research is still developing, and findings have been mixed across different study populations.

EPA and DHA: why they matter differently for heart health

EPA and DHA are often discussed together, but they are distinct molecules with different tissue distributions and biological effects.

EPA (eicosapentaenoic acid) is a 20-carbon omega-3 fatty acid that integrates into cell membranes and influences inflammatory and lipid pathways. A 2024 systematic review in Frontiers in Nutrition compared the independent effects of EPA and DHA across randomised controlled trials and noted that both fatty acids contribute to triglyceride management, with DHA also associated with modest increases in HDL cholesterol. EPA appears to have distinct effects on membrane stability and cholesterol distribution within cell membranes, which may influence endothelial function.

DHA (docosahexaenoic acid) is a 22-carbon omega-3 that is highly concentrated in the brain, retina and cardiac tissue. In cardiovascular contexts, DHA contributes to membrane fluidity and is involved in the formation of membrane domains that influence cell signalling.

A 2024 meta-analysis in the European Journal of Preventive Cardiology examined 18 RCTs with 134,144 participants and found that omega-3 supplementation (both EPA alone and EPA combined with DHA) was associated with reduced risk of cardiovascular complications. The review noted that EPA monotherapy showed greater effects for some endpoints, though combined EPA and DHA formulations also demonstrated meaningful associations across several cardiovascular outcomes.

For general cardiovascular support, formulations containing both EPA and DHA align with the bulk of the research, which has predominantly studied the two fatty acids together.

What the latest research shows

The evidence base for omega-3 and cardiovascular health has grown considerably in recent years, with several large-scale analyses published since 2024.

A 2025 systematic review and meta-analysis with meta-regression in Clinical and Translational Discovery pooled data from 42 studies involving 176,253 participants and found that omega-3 fatty acid supplementation was associated with a statistically significant reduction in cardiovascular outcomes in patients with established cardiovascular disease or at high cardiovascular risk.

The previously mentioned 2024 European Journal of Preventive Cardiology meta-analysis of 18 RCTs found associations between omega-3 supplementation and reduced risk of cardiovascular complications. These associations persisted in participants already taking statins as part of their existing treatment regimen.

A 2024 systematic review and meta-analysis in the Journal of Clinical Medicine specifically examined circulating blood omega-3 levels as biomarkers and found that higher EPA and DHA levels in red blood cells were inversely associated with cardiovascular mortality in a pooled analysis of 310,955 participants across 10 prospective cohort studies.

While these findings are consistent with a protective association, it is worth noting that individual RCTs have produced variable results depending on study population, dose, formulation and duration. The weight of evidence from meta-analyses and large cohort studies supports a role for omega-3 in cardiovascular health, but no single study is definitive on its own.

Diet, lifestyle and omega-3 for cardiovascular wellbeing

Food sources of omega-3

Oily fish remains the richest dietary source of EPA and DHA. Salmon, sardines, mackerel, herring and trout all provide substantial amounts per serve. The Heart Foundation recommends that all Australians consume 250 to 500 mg of combined EPA and DHA daily, equivalent to two to three serves of fish per week, including oily varieties.

Plant sources such as flaxseed, chia seeds and walnuts provide ALA (alpha-linolenic acid), a shorter-chain omega-3 that the body can convert to EPA and DHA. This conversion is limited; estimates place it at around 6% for EPA and less than 4% for DHA, making direct dietary or supplemental sources of EPA and DHA more efficient for meeting cardiovascular needs.

Omega-3 within a broader lifestyle approach

Omega-3 intake is one component of cardiovascular health, not the whole picture. The AIHW’s data on cardiovascular disease burden shows that dietary risks, high blood pressure, high cholesterol, excess weight and physical inactivity all contribute significantly. A heart-healthy approach includes regular physical activity, a diet rich in vegetables, fruits, whole grains and lean proteins, maintaining a healthy weight, not smoking and managing stress.

Omega-3s fit within this broader pattern as a dietary factor that may contribute to cardiovascular wellbeing alongside, not instead of, these other lifestyle measures.

When dietary intake falls short

Despite the Heart Foundation’s recommendation for two to three serves of fish per week, many Australians do not reach this target consistently. For those who eat little or no oily fish, supplementation offers a practical way to maintain omega-3 intake. Fish oil supplements provide pre-formed EPA and DHA in concentrated amounts, bypassing the inefficient ALA conversion pathway.

Choosing an omega-3 supplement for heart support

If you’re considering a fish oil supplement for cardiovascular support, several factors are worth evaluating.

EPA and DHA concentration

The total fish oil content on a label does not reflect the actual omega-3 dose. A product labelled as 1000 mg of fish oil may contain only 300 mg of combined EPA and DHA. For cardiovascular support, the EPA and DHA amounts per capsule are the figures that matter. Higher concentration formulations reduce the number of capsules needed to meet your target intake.

Purity and quality testing

Fish can accumulate environmental contaminants, including mercury, dioxins and PCBs. Reputable manufacturers test for these contaminants and also measure oxidation levels, which indicate freshness. Rancid fish oil is less effective and more likely to cause digestive discomfort.

Products to consider

Blackmores Omega Triple Super Strength Fish Oil contains 1,500 mg of concentrated fish omega-3 triglycerides per capsule, providing 540 mg EPA and 360 mg DHA (900 mg total omega-3). This is three times the omega-3 concentration of a standard 1,000 mg fish oil capsule. It is extracted from 100% wild caught fish and rigorously tested for mercury, dioxins and PCBs.

For those seeking a higher potency formulation, Blackmores Omega Platinum delivers 720 mg EPA and 480 mg DHA per capsule (1,200 mg total omega-3), along with vitamin E as an antioxidant. This formulation provides a broader range of support including cardiovascular system health, heart health, heart function, healthy blood circulation and blood vessel health, making it suited to those looking for more comprehensive cardiovascular support in a single daily capsule.

Frequently asked questions

Is omega-3 good for heart health?

The weight of evidence from large-scale meta-analyses and prospective cohort studies supports an association between adequate omega-3 intake (particularly EPA and DHA) and cardiovascular wellbeing. EPA and DHA are involved in maintaining healthy blood lipid levels, supporting blood vessel function and contributing to inflammatory regulation. The Heart Foundation recommends 250 to 500 mg of combined EPA and DHA daily for all Australian adults.

How much omega-3 is recommended for heart health?

The Heart Foundation recommends 250 to 500 mg of combined EPA and DHA per day for general cardiovascular wellbeing. This equates to two to three serves of fish (including oily fish) per week. Individual requirements may vary, and your healthcare professional can advise on the appropriate intake for your circumstances.

Does fish oil help with cholesterol?

EPA and DHA are involved in blood lipid metabolism and may contribute to the maintenance of healthy blood lipid levels, particularly triglycerides. They do not replace cholesterol-lowering medication where prescribed. If you have concerns about your cholesterol levels, speak with your healthcare professional about a management plan that may include dietary changes, exercise and, where appropriate, supplementation.

Can omega-3 reduce inflammation in the cardiovascular system?

EPA and DHA are precursors to specialised pro-resolving mediators that play a role in inflammatory regulation. Omega-3 supplementation has been associated with reductions in inflammatory markers in research settings. For products with a TGA-listed anti-inflammatory indication, such as Blackmores Omega Triple, this benefit extends to relieving inflammation and symptoms of mild arthritis.

Should I take fish oil if I already eat fish regularly?

If you eat oily fish such as salmon, sardines or mackerel two to three times per week, you may already be meeting the Heart Foundation’s recommended intake of 250 to 500 mg EPA and DHA daily. Supplementation is most useful for those who do not regularly consume oily fish or who want to ensure consistent daily intake.

Key takeaways

Omega-3 fatty acids, particularly EPA and DHA, are among the most extensively studied nutrients in cardiovascular research. They are involved in blood lipid metabolism, inflammatory regulation, blood vessel function and heart rhythm stability. Large-scale meta-analyses and prospective cohort studies consistently associate adequate omega-3 intake with cardiovascular wellbeing, though individual study results have varied depending on population, dose and formulation.

The Heart Foundation recommends 250 to 500 mg of combined EPA and DHA daily for all Australian adults. Most Australians do not meet this target through diet alone. For those looking to maintain their omega-3 intake, a concentrated fish oil supplement with verified EPA and DHA content, tested for purity, offers a practical option alongside a balanced diet and active lifestyle.

Always read the label and follow the directions for use.

Disclaimer: This article provides general information only and is not intended to diagnose, treat, cure, or prevent any disease. The information presented is not a substitute for professional medical advice. If you have concerns about your health, please consult your GP or healthcare provider for a personalised assessment and recommendations. Supplements should not replace a balanced diet.