Breakthrough study reveals the secret to fish oil’s heart benefits

It seems not a day goes by without seeing another study on the health benefits of omega-3s. The big story for years now has been their ability to protect against heart disease. More recently, studies have suggested that omega-3s have an “anti-inflammatory” or (perhaps more correctly) an immune- modulating effect—helping to keep the immune system in balance. At the same time, other studies are showing that heart disease may be caused by inflammation (or again, an imbalanced immune system) as I reported in last month’s issue.

These ideas are getting us closer to understanding the all-important “mechanism of action”—or how omega-3s actually work in the body to reduce disease. For most doctors, and certainly for all patients, it is enough to know that something does work. But medical researchers don’t rest until they establish how it works.

So this new research is especially interesting. And one recent study in particular caught my eye.

It tested whether fish oil could reduce blood pressure, heart rate, and nervous system responses—by blunting the body’s reactions to mental stress.1

These researchers were smart enough to recognize something I’ve told you many times—that the main culprit behind high blood pressure and heart disease isn’t salt…or saturated fat…or tobacco.


The link between mental stress and heart disease risk is well- documented. Yet, until now, no study ever examined how fish oil (omega-3) supplementation affects this link.

Researchers subjected 67 participants with normal blood pressure to a 5-minute mental stress test before and after 8 weeks of fish oil supplementation or placebo.

They found that fish oil significantly reduced both heart rate and overall nervous system reactivity to mental stress.

The researchers (perhaps focusing too much on their own study rather than the bigger picture) expressed concern that, despite its other benefits, fish oil did not lower blood pressure. But considering the study participants all had normal blood pressure to begin with, this particular finding makes perfect sense.

Other studies have shown that fish oil can reduce blood pressure in people who DO have elevated blood pressure, or hypertension. So this simply appears to be another instance where we should credit the “wisdom of the body” (and basic physiologic processes) for not “fixing” problems that don’t actually exist!

And it certainly isn’t cause to “throw the baby out with the bathwater,” so to speak. Because this research revealed a real breakthrough if you can see the bigger picture.

A valuable insight that moves us closer to understanding how omega-3 fish oils have their benefits in heart disease.

Short-term results indicate long- term benefits

Over the short term, blood pressure constantly goes up and down—but settles out at a resting “set point.”

Chronic stress causes that “set point” to rise. The body eventually readjusts at a higher blood pressure—causing ongoing “wear and tear” damage to our heart and blood vessels. Stress also causes increases in nervous system reactivity and heart rate.

The ability of fish oil to reduce heart rate and nervous system responses to stress within just 8 weeks is a good sign it will also help keep blood pressure normal and the heart healthy over the longer term.

And don’t forget that fish oil has previously been shown to reduce triglyceride levels in the blood and decrease growth of atherosclerotic plaques in blood vessels—which result after the wear-and-tear of elevated blood pressure and inflammation.

When you have a vicious cycle of patho-physiologic factors causing a disease, you need a real cure that knocks out all the negative effects (not just a drug that has one effect). And fish oil offers the “whole package” when it comes to heart health.

I recommend everyone take at least 1 to 2 grams per day of omega-3 fatty acids from fish oil.

Ideally, you should be looking for dietary sources of omega-3s, such as salmon, sardines, and other fatty fish. Of course, if you don’t like fish, purified omega-3s and fish oil supplements are widely available (Nordic Naturals makes some good quality products that I have personally tested over the years).


1. “Fish oil and neurovascular reactivity to mental stress in humans,” AJP Regu Physiol 2013: 304(7): R523-R530