Low Omega-3 Index Linked to Early Atherosclerosis
A recent study published in the European Journal of Clinical Nutrition found that patients in the early stages of atherosclerosis had low Omega-3 Index levels.
Researchers measured coronary artery calcification (CAC), which is calcium buildup in the arteries that narrows blood vessels and is considered one of the strongest predictors of heart disease. Using non-invasive CT scans and the Agatston scoring method, they evaluated CAC alongside participants’ Omega-3 Index.
Among 71 patients, those with early CAC had significantly lower Omega-3 Index levels compared to those without, independent of other risk factors like age, gender, or statin use. This suggests that low blood levels of EPA and DHA are directly associated with early arterial damage.
Aortic Calcification and DHA’s Role
This isn’t the first time omega-3s have been connected to arterial health. In a multiethnic study of over 1,000 men aged 40–49, researchers examined aortic calcification—calcium buildup on the aortic valve. They discovered that higher DHA levels, but not EPA, were inversely linked with aortic calcification.
This finding highlights that omega-3s may help protect against different forms of vascular calcification, with DHA playing a particularly important role in aortic valve health.
Omega-3s and Peripheral Artery Disease (PAD)
Another study published in Lipids examined 145 patients with PAD (atherosclerosis of the leg arteries) compared to 34 controls. Results showed:
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PAD patients had a lower Omega-3 Index (5% vs. 6% in controls).
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For every 1% drop in the Omega-3 Index, the odds of having PAD increased by 39%.
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Smoking compounded the risk, with each pack-year increasing PAD odds by 4%.
Researchers believe the anti-inflammatory properties of omega-3s may help explain why higher blood levels are protective.
Evidence from Meta-Analyses
A 2018 update of the Cochrane Review reported statistically significant risk reductions from omega-3s:
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8% lower cardiovascular mortality
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9% lower coronary heart disease events
However, the same review and others also found a slight increase in prostate cancer risk. For example, if 1,000 people took omega-3 supplements for four years, researchers estimated that:
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3 would avoid dying from heart disease,
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6 would avoid a heart attack,
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but 3 more would develop prostate cancer.
Thus, while the cardiovascular benefits are real, they are modest, and ongoing research is needed to clarify long-term effects and balance risks.
Beyond Supplements: Fish as a Nutrient-Rich Source
It’s important to note that most studies focus on fish oil supplements, not whole fish. Oily fish like salmon, sardines, and herring provide not only omega-3 EPA and DHA but also protein, vitamin D, selenium, iodine, and calcium—making them more than just an omega-3 source.
At the same time, environmental concerns about overfishing and supplement production mean sustainability is an important factor in future recommendations.
Key Takeaways
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Low Omega-3 Index is strongly linked to early arterial calcification (both coronary and aortic).
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Patients with PAD have significantly lower Omega-3 Index levels, supporting omega-3s’ role in vascular health.
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Meta-analyses confirm modest cardiovascular benefits of omega-3s, though risks like prostate cancer must be monitored.
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Whole fish remains a superior nutrient source, but high-quality omega-3 supplements can help individuals reach a protective Omega-3 Index of 8–12%.