Can Omega-3 Improve Risk Factors for Heart Disease?

About the author: Judy Blatman is OmegaQuant’s consumer health writer. Her blogs tee-up practical suggestions for health, with an emphasis on omega-3s and omega-3 testing, so readers can decide their own path to good health. Prior to her work with OmegaQuant, she had an extensive public relations career, representing dog food, coffee and OTC anti-itch medication, luxury resorts, liquor, and more. Judy’s knowledge about dietary supplements developed during her 16 years spearheading communications for Council for Responsible Nutrition, where she led an award-winning healthy lifestyle consumer education initiative focused on diet, dietary supplements and exercise. Starting her own communications firm during COVID led her back to one of her original career aspirations—writing. She is fond of collecting handbags, playing with other people’s dogs, and binge-watching the latest comedies, dramas and thrillers. Learn more.

 

 

Heart disease is serious business. It’s the leading cause of death in America for both men and women and for most ethnic and racial groups, according to government statistics. What’s more, one person in this country dies every 33 seconds from cardiovascular disease, with the 2022 statistics showing that more than 700,000 people died from heart disease, equal to 1 in every 5 deaths in the U.S.

And if those statistics don’t make you think twice about your own heart health, think of the societal cost to America’s health care system: heart disease cost the US about $252 billion between 2019 and 2020. That statistic included the cost of healthcare services, medicines and lost productivity due to death.

Let’s talk definitions first. Heart disease is one type of cardiovascular disease, making the two related, but not interchangeable. According to the World Health Organization (WHO), cardiovascular diseases (CVDs) represent a group of disorders of the heart and blood vessels, including coronary heart disease (CHD).

CHD impacts the blood vessels supplying the heart muscle and is the most common type of heart disease. In 2022, coronary heart disease killed 371,506 people in the U.S.

Coronary heart disease and coronary artery disease (CAD) are often used interchangeably, especially by healthcare professionals; however, CHD is actually a result of CAD, which occurs from plaque builds up on the coronary artery walls, eventually limiting  blood flow to the heart muscle, strangling oxygen flow.  This can happen over time causing the coronary artery to narrow, or it can happen acutely when the plaque ruptures suddenly and a blood clot forms. Approximately 1 in 20 adults aged 20 and older have CAD.

VIDEO: Why Your Surgeon is Wrong About Omega-3 (Latest Research)

 

What are Risk Factors for Heart Disease? 

The biggest risk factors for heart disease are smoking, high blood pressure and high cholesterol. Nearly half (47%) of people in the U.S. have at least one of these issues.

Other risk factors include diabetes, obesity, eating unhealthily, a sedentary lifestyle, and drinking too much alcohol. Read more here.

There’s an additional risk factor, one that’s close to our hearts here at OmegaQuant. It’s scoring at the lowest end of the Omega-3 Index.

Let’s explain. The Omega-3 Index is a simple, finger prick blood test that you can purchase and take at-home to measure the levels of omega-3 EPA and DHA in your blood. It was developed by OmegaQuant founder, William S. Harris, Ph.D., president and founder at the Fatty Acid Research Institute (FARI), and a co-inventor of the Omega-3 Index.

According to Dr. Harris, the Omega-3 Index fulfills the following the requirements for a risk factor: including consistent epidemiologic evidence, a plausible mechanism of action, a reproducible assay, and the demonstration that raising levels will reduce risk for cardiac events.

The Omega-3 Index measures the amount of EPA and DHA in your red blood cell membranes. The test results are expressed as a percentage: if you score 8% or higher, you are in the lowest risk zone for coronary heart disease; however, if you score in the lowest percentile, 4% or below, you are in the highest risk zone. Being in the highest risk zone means you may have up to a 90% higher risk of sudden cardiac death. Read more here.

Fortunately, risk factors are modifiable. If you are a smoker, breaking that habit can help lower your risk of heart disease; if your blood pressure or cholesterol levels are high, taking steps to reduce those conditions can do the same.

If you know where you fall on the Omega-3 Index, there are simple steps you can take to improve that score. The first step is knowing your numbers. Learn more here.

VIDEO: The Science of Inflammaging & Omega-3 Resolution Pathways

 

Omega-3s & Heart Health: The Science

Omega-3s are best known for their heart health benefits. In fact, it’s those benefits—especially the anti-inflammatory properties and triglyceride-lowering effects—that place them in the heart healthy nutrient category.

Let’s look at the current state of the science for omega-3s and heart health conditions.

Omega-3 and Triglycerides

Triglycerides are a type of fat found in your blood, one that is an important measure of your heart health, according to this post. Along with blood  pressure and cholesterol test results, testing the triglycerides in your blood is equally important. Normal triglyceride levels are less than 150 mg/dL; borderline high levels range from 150-188 mg/dL; high levels are 200-499 mg/dL; and very high are 500 mg/dL or higher.

High triglyceride levels lead to hardening of the arteries and thickening of the artery walls, putting you at a higher risk for stroke, heart attack and heart disease. Your doctor will order a lipid panel test (also called a lipid profile) to test not only your cholesterol numbers but also your triglycerides.

There is strong research to support omega-3 EPA and DHA (aka fish oil) for lowering triglyceride levels, for fatty fish, fish oil supplements and prescription omega-3 medications. There are currently two FDA-approved omega-3 brand name drugs on the market (Vascepa and Lovaza) and generic options, used to lower very high triglycerides in your blood. You must meet certain criteria to obtain a doctor’s prescription needed for these medications.

Dietary supplements, by law, cannot make the same treatment claims as prescription drugs; however, the same omega-3 nutrients (EPA, DHA) found in the prescription medications can be purchased over-the-counter as dietary supplements. The fish oil prescription medications have very specific doses and while dietary supplements can be found in those doses, there are a wide range of dietary supplements when it comes to omega-3 fish oil. Both the medications and the supplements have strong safety profiles.  Read more here.

Omega-3 and Blood Pressure

The scientific literature assessing the role of omega-3s in lowering blood pressure has shown inconsistent results, with some studies showing benefit in doing so, and others coming back with null results, meaning that the study hypothesis was not supported by the study results.

One of the reasons a null result can occur could be related to the dose selected in the study, demonstrating that identifying the right dose is paramount to successful scientific research.

This 2022 systematic review and meta-analysis added a nuanced layer to the question about omega-3s and lowering blood pressure by identifying an optimal dose-response of about 3 grams daily of omega-3 EPA and DHA for lowering blood pressure.

The results: those consuming between 2-3 grams daily of omega-3 fatty acids EPA and DHA saw an average modest reduction of 2 mm Hg in systolic and diastolic blood pressure compared to those who did not consume EPA and DHA. The benefits for those with high blood pressure (aka hypertension), consuming 3 grams daily of omega-3 EPA and DHA lowered systolic blood pressure by 4.5 mm Hg on average versus by 2 mm Hg for those with normal blood pressure.

Those with hypertension consuming 5 grams daily of omega-3s, saw an average reduced systolic blood pressure of nearly 4 mm Hg and those without hypertension experienced a less than 1 mm Hg average decline, reinforcing the importance of finding the right dose.  Read more here.

Omega-3 and Atrial Fibrillation

The most common type of heart arrhythmia is atrial fibrillation, also known as AFib.  A heart arrhythmia happens when the upper and lower chambers of your heart are not properly working in sync, resulting in your heart beating too slowly, too quickly or inconsistently. AFib is a major risk factor for ischemic strokes, those caused by blood clots.

Nearly 40 million people worldwide, including six million here in the U.S., have AFib, and the latter stats are expected to double by 2030. With that kind of impact, it shouldn’t be surprising that scientists are interested in studying how  omega-3 fatty acids may be useful for AFib, given the nutrient’s other heart health benefits.

Unfortunately, the answer to the question of whether omega-3 can help control or treat AFib is not clearcut. The early studies were promising, finding only favorable or neutral relationships between omega-3 and AFib, nothing in the relationship that would cause safety concerns.

According to Dr. Harris, based on the research at the time, the research community assumed that these safe and beneficial results would continue to be the norm as research progressed.

But instead, the story took a turn. In 2010, a prospective, randomized, double-blind placebo-controlled study, with patients receiving prescription 8g/d or placebo for the first 7 days, followed by prescription omega-3 (4 g/d) or placebo thereafter through week 24, found that “among participants with paroxysmal AF, 24-week treatment with prescription omega-3 compared with placebo did not reduce recurrent AF over 6 months.”

That was a disappointing result, but Dr. Harris saw something more surprising in the results. He noted that although not statistically significant, there was a trend towards more AFib in the treatment group. Surprising because as the authors contextualized in their study, “limited data from small trials suggest omega-3 PUFAs may provide a safe, effective treatment option for AF patients.”

Then another large study set out to determine whether perioperative omega-3 supplementation could reduce postoperative AFib. Patients were randomized to receive 1g capsules of fish oil containing ≥840 mg omega-3 fatty acids or placebo, with preoperative loading of 10g over 3 to 5 days (or 8g over 2 days) followed postoperatively by 2g/d until hospital discharge or postoperative day 10, whichever came first.

The authors reported the results: when compared with placebo, the omega-3 PUFAs did not reduce the reduce the risk of postoperative AF. Although it was a null result, Dr. Harris pointed out that there was no suggestion of any increased risk for AFib in the treatment group.

More recent studies have seen more inconsistent results—some with benefits, some without. This see-saw effect is not unusual when it comes to the science, but it is not ideal. It can cause figurative whiplash in patients wondering whether omega-3s can be beneficial for AFib.

A study published earlier this year hoped to provide clearer answers to the omega-3 and AFib question. This new meta-analysis led by researchers from the Fatty Acid Research Institute (FARI) provides the clearest picture to date of the relationship between omega-3 fatty acid supplementation and Afib, helping resolve years of confusion generated by earlier reports.

Published in Circulation: Arrhythmia and Electrophysiology, the study, analyzed data from 35 randomized controlled trials involving 114,592 participants—more than four times the number of studies included in previous meta-analyses. Researchers also incorporated unpublished trial data and previously unavailable safety information to provide the most comprehensive assessment of AF risk to date.

The analysis found that low-dose omega-3 supplementation (less than 1,500 mg/day EPA+DHA) was not associated with an increased risk of AF, even among individuals at elevated cardiovascular risk.

In contrast, only in the setting of high-dose omega-3 therapy (>1,500 mg/day, typically prescription-strength formulations) used in patients with established cardiovascular disease was AF risk modestly increased (i.e., the absolute risk increase was 0.8%).

“Our findings show that the relationship between omega-3s and atrial fibrillation is much more nuanced than previous headlines suggested,” said Dr. Harris. “For the vast majority of people taking nutritional doses of omega-3s, these data should provide reassurance that there is no meaningful increase in atrial fibrillation risk.”

Our advice: when making decisions about omega-3s and AFib it’s important to also consider your own individual risks for AFib. Especially if you have a history of AF, discuss with your doctor whether to avoid high doses of omega-3 in prescription drugs or in omega-3 supplements. Do what you can to decrease your risk factors for AF and try to follow the American Heart Association’s guidelines of at least 2 servings of fatty fish weekly.

Omega-3 and Stroke

Cerebrovascular disease, the most common type of life-threatening injury to the brain in the U.S. and the fifth most common cause of death, according to the Cleveland Clinic, is another type of CVD involving the blood vessels supplying the brain. Conditions from this disease include strokes, brain bleeds, brain aneurysms, and carotid artery disease.

Much of the research on omega-3s available to date focuses on the broad category of cardiovascular outcomes, rather than specifically on an association between omega-3 consumption and stroke. In that regard, a systematic review and meta-analysis from 2021included 38 trials and 149,000+ patients. The authors reported a moderate certainty of evidence favoring omega-3s for reduced cardiovascular mortality and other cardiovascular outcomes.

Other large trials have found similar results, including the REDUCE-IT trial, which showed that in patients with elevated triglyceride levels, the risk of ischemic events, including cardiovascular death, was significantly lower among those who received 2g of omega-3s (as icosapent ethyl) twice daily compared to placebo.

This published paper using data from the Framingham Heart Study reported that in 2500 people, a higher Omega-3 Index was associated with significantly lower risks for total mortality and for total CVD events. Those with the highest (>6.8%) compared to those with the lowest Omega-3 Index (<4.2%) had a 39% lower risk for incident CVD. The authors concluded that the Omega-3 Index could serve as a marker of overall health in older Americans.

This 2023 study pooled analyses across 29 prospective studies to investigate the association between omega-3 status and total, ischemic, and hemorrhagic stroke incidents. Over 180,000 individuals across 15 different countries with an average age of 65 were included in the analyses. When analyzing by quintile, a significant inverse association was observed between DHA, EPA, and EPA + DHA and the risk of total stroke and ischemic stroke. Omega-3 levels were not significantly associated with hemorrhagic stroke.

The majority of strokes, one source says 87%, are ischemic, meaning they are a result of a blot clot. One of the many health benefits of omega-3 fatty acids is the nutrient’s anticoagulant and antiplatelet effects. Human studies confirm that 2-4 grams of omega-3 EPA and DHA daily can decrease the risk of blood clots and cardiovascular risk factors. Read more here and here.

Previously there has been concern that omega-3s may increase the risk of bleeding. But research published in May 2024 in the Journal of the American Heart Association should put that concern to rest with definitive data that shows omega-3 fatty acids are not associated with increased bleeding risk.

VIDEO: The Omega-3 Index and Stroke

 

Bottom Line:  Help improve your risk factors for heart disease by leading a healthier lifestyle. Consider Omega-3 Index testing as one more way to reduce your risk. Add omega-3 EPA and DHA depending on your Omega-3 Index test results. Talk with your doctor to determine what is right for you.