What the Omega-3 Index May Reveal About Longevity

Okay, let's switch topics. I want to talk about omega-3s. This topic is very important to me, and I'm really obsessed with it. The person who introduced me mentioned that I am an associate scientist at the Fatty Acid Research Institute, which was established by Dr. Bill Harris. I'm involved with research, particularly looking at how omega-3 fatty acids affect the brain.

I think it's really important to talk about because most people are not eating seafood or fish. About 90 percent of the global population does not get enough omega-3 fatty acids from seafood. A Harvard study published a few years back identified the top six preventable causes of death. In other words, these are things that are pretty preventable and will have a dramatic effect on your life expectancy. They included avoiding hypertension, type 2 diabetes and cardiovascular disease, and not smoking. Low omega-3 intake from seafood was on that top-six list along with the things I just mentioned.

There are three omega-3 fatty acids. The ones found in seafood are EPA and DHA. Those are found in marine sources. ALA is the plant source of omega-3. That was not part of the equation for one of the top six preventable causes of death. As I said, most people are not eating enough seafood or supplementing with omega-3s.

You can measure your omega-3 levels with an Omega-3 Index test. You want to measure your omega-3 levels in red blood cells because red blood cells take about 120 days to turn over. They're more of a long-term marker of omega-3 status than plasma phospholipids. The Omega-3 Index test is a really good way to measure omega-3 levels. It was pioneered by Bill Harris and one of his colleagues many years ago. I think it was back in 2004, about 20 years ago. They identified what is called the Omega-3 Index, including a high index and a low index. A high Omega-3 Index is around 8 percent or more, and a low index is 4 percent or lower.

One of their first publications found that people with a high Omega-3 Index of 8 percent or more had a 90 percent lower risk of sudden cardiac death. That means if you're having a heart attack, which happens about every 30 seconds in the United States, you're 90 percent less likely to die from that heart attack if you have a high Omega-3 Index. You're also less likely to experience the heart attack.

Since then, Bill and his colleagues have published many studies looking at different cohorts, including the Framingham cohort and UK Biobank data. There are lots of big cohort datasets out there, and I think the message is clear. People with a high Omega-3 Index have about a five-year increase in life expectancy compared with people who have a low Omega-3 Index. This is after correcting for all these confounding variables.

If you think about average seafood intake in the United States versus Japan, it's much higher in Japan. The Omega-3 Index in Japan is about 10, which is very high. In the United States, the average Omega-3 Index is about 5 percent, so we're on the low end. Japan has about a five-year increase in life expectancy compared with the United States for both men and women.

Within the Framingham data, Bill and his colleagues plotted the Omega-3 Index and looked at smokers versus non-smokers. This is where it becomes so clear to me. One of the worst things you can do for your cardiovascular health and your heart is smoke. Most people think about lung cancer. Forget lung cancer. That risk increases in a linear fashion decades later. Cardiovascular disease happens pretty quickly. Smoking is really bad for your heart, and we know omega-3s are really good for your heart.

If you look at the slide, the green curve is the life-expectancy curve for non-smokers with a high Omega-3 Index. The red curve, which shows the people with the lowest life expectancy, represents smokers with a low Omega-3 Index. That's no surprise. But my biggest surprise was that the orange and blue curves are almost perfectly overlaid. Smokers with a high Omega-3 Index had the same life expectancy as non-smokers with a low Omega-3 Index. In other words, not getting enough omega-3 was like smoking for life expectancy. That's something I think people should consider.

Obviously, smokers might jump up and down and say, "I can take a fish-oil supplement and be healthy." But what we should really be thinking about is that we're not eating enough seafood or supplementing with a high-quality fish-oil supplement to get our Omega-3 Index into that 8 percent range. We'll talk about what it takes to get there.

For even stronger data, we can turn to some of the large randomized controlled trials of omega-3 supplementation. In REDUCE-IT, large populations received four grams per day of Vascepa, a purified EPA product, for up to five years. The risk of a cardiovascular event, whether a heart attack or stroke, was reduced by 25 percent compared with placebo.

Then there was the STRENGTH study. It was stopped early because there was no benefit. The product used a free-fatty-acid form that was not esterified to anything, which can be very irritating to the gut.

Then there was the VITAL study. In my opinion, people received a low dose, about 840 milligrams of DHA and EPA combined. This was also a five-year study. In the secondary outcomes, heart-attack risk was reduced by almost 30 percent, and total coronary heart disease was reduced by 17 percent. This happened particularly among people with low fish intake.

I think we have a lot of evidence that omega-3 is very important for cardiovascular health, and it doesn't take a lot. In fact, it takes about 1.5 to 2 grams of a fish-oil supplement per day to get someone from a low Omega-3 Index to a high Omega-3 Index. It's very achievable.