What Does the Omega-3 Index Tell You About Your Heart Health?

by Bianca Garilli, ND

Coronary heart disease (CHD) is the most common form of heart disease in the US, resulting in over 370,000 deaths annually.¹ Because of its frequent and often fatal nature, it is important to understand the risk factors associated with heart disease and ways to mitigate that risk.

A partial list of common CHD risk factors include: elevated blood pressure and cholesterol levels, diabetes and prediabetes, smoking, overweight or obesity, sedentary lifestyle, family history of early heart disease, unhealthy diet, and being over the age of 55 for women.² Nearly half of all Americans (47%) have at least 1 of the 3 key risk factors for heart disease: high blood pressure, high cholesterol, and smoking.³

There are several lesser-known risk factors for heart disease that are important for practitioners and individuals to consider when assessing risk. One of these is the omega-3 index.⁴

 What is the omega-3 index?

The omega-3 index is a biomarker measure of long-term omega-3 status, which is quantifiable and modifiable. The index measures the erythrocyte membrane eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) levels from the blood; results are expressed as a percentage of total erythrocyte FAs.⁴ Measuring erythrocyte membrane FA concentrations aligns with the fact that FAs are active within the membrane itself by altering physical characteristics and influencing the activity of membrane-bound proteins; they also serve as ligands for various nuclear transcription factors thus influencing gene expression.⁴ An important area of influence from these FAs is in their ability to reduce inflammatory processes and lower blood pressure.⁴ Although exact mechanisms are unclear, it would seem that many of the activities mediated by the presence of EPA and DHA in the erythrocyte play a role in influencing overall heart disease risk.⁴

What is a healthy omega-3 index goal?

• Omega-3 index ≥8% – associated with greatest cardioprotection⁵
• Omega-3 index ≤4% – associated with the least cardioprotection⁵

Recent research has revealed the importance of the omega-3 index in assessing CHD risk, in particular for sudden cardiac death.^5-6 A meta-analysis of 10 cohort studies published in Atherosclerosis confirmed the aforementioned recommendations, supporting the use of <4% (higher risk) and >8% (lower risk) as clinical cutoffs for the omega-3 index.⁶ The study further noted the potential to reduce risk for fatal CHD by approximately 30% if the omega-3 index increased from the lowest quintile (median: 4.2%) to the highest quintile (median: 8.3%), i.e., into the recommended therapeutic range for cardioprotection.⁶ Furthermore, evidence points towards the greater benefit of achieving a healthy omega-3 index score in individuals who are already at high risk for a cardiovascular event, including those with elevated triglycerides and low density lipoproteins (LDL).⁷

Omega-3 index: A look into the fountain of youth?

Recent evidence has linked a higher omega-3 index with a lower rate of telomere attrition, indicative of a slower rate of cellular aging. This fascinating research published in the Journal of American Medical Association found a clear inverse association; over a 5-year time frame in 600+ patients with stable CHD, those individuals with the lowest quartile of omega-3 index levels experienced the fastest rate of telomere shortening, while those in the highest quartile experienced the slowest rate of telomere shortening.⁸

How to measure and improve your omega-3 index

It is important to measure the omega-3 index, but it is more important to have practical tools to improve upon the score. Omega-3 index lab testing can be requested through primary health care providers. The ability to improve the omega-3 index depends on various factors, some modifiable and others fixed. Fixed factors influencing omega-3 levels include age, while modifiable factors known to impact the omega-3 index include (in decreasing order):⁹

• Omega-3 supplementation- specifically EPA+DHA
• Frequency of fish consumption- especially oily (omega-3-rich) fish
• Triglyceride level
• History of high cholesterol
• Smoking

Since all of these modifiable factors can be directly impacted by lifestyle interventions leveraging nutrition, physical activity, and behavior change, the potential to improve upon the omega-3 index is great, particularly with the right healthcare practitioner partnership.

Citations

1. CDC. Heart disease facts. https://www.cdc.gov/heartdisease/facts.htm. Accessed September 19, 2018.
2. US Department of Health and Human Services. Lower heart disease risk. https://www.nhlbi.nih.gov/health/educational/hearttruth/lower-risk/risk-factors.htm. Accessed September 19, 2018.
3. Fryar CD et al. Prevalence of uncontrolled risk factors for cardiovascular disease: United States, 1999–2010. NCHS Data Brief. 2012(103):1-8.
4. Harris WS. The omega-3 index as a risk factor for coronary heart disease. Am J Clin Nutr. 2008;87(6):1997S-2002S.
5. Harris WS et al. The omega-3 index: a new risk factor for death from coronary heart disease? Preventive Medicine. 2018;39(1):212-220.
6. Harris WS et al. The omega-3 index and relative risk for coronary heart disease mortality: estimation from 10 cohort studies. Atherosclerosis. 2017;262:51-54.
7. Alexander DD et al. A meta-analysis of randomized controlled trials and prospective cohort studies of eicosapentaenoic and docosahexaenoic long-chain omega-3 fatty acids and coronary heart disease risk. Mayo Clin Proc. 2017;92(1):15-29.
8. Farzaneh-Far R et al. Association of marine omega-3 fatty acid levels with telomeric aging in patients with coronary heart disease. JAMA. 2010;303(3):250-257.
9. Block RC et al. Determinants of blood cell omega-3 fatty acid content. Open Biomark J. 2008;1:1–6.

Bianca Garilli, ND

Dr. Garilli is a former US Marine turned Naturopathic Doctor (ND). She works in private practice in Northern California as well as running a consulting company working with leaders in the natural and functional medicine world such as the Institute for Functional Medicine and Metagenics. She is passionate about optimizing health and wellness in individuals, families, companies and communities- one lifestyle change at a time. Dr. Garilli has been on staff at the University of California Irvine, Susan Samueli Center for Integrative Medicine and is faculty at Hawthorn University. She is the creator of the Veterans for Health Initiative and is the current President of the Children’s Heart Foundation, CA Chapter.