Salmon on a bed of greens, which may reduce risk of peripheral artery disease.

It’s no secret that omega-3 fatty acids, the kind found abundantly in fish, provide a host of benefits for the heart and body. And a new study published in the Journal of the American College of Cardiology shows strong links between consuming fish regularly and lowered risk of peripheral artery disease, or PAD.

About one in 20 Americans over age 50 suffer from PAD—a disease caused by plaque buildup typically in leg arteries, leading to leg pain and difficulty walking. Untreated, it can stop circulation in the leg and even lead to amputation. People who have PAD are also at higher risk for heart attack and stroke.

More About Fish

As part of a research study called the Danish Diet, Cancer, and Health Study, researchers took samples of fatty tissue from a large group of participants between 1993 and 1997, testing—among other things—their tissue's levels of the omega-3s found in fish. 

In a randomly selected group of 3,204 study participants, the researchers found that those with the highest omega-3 levels were 29 percent less likely to develop PAD than those with the lowest levels.

“This study adds to a growing body of research that shows strong links between a diet high in fish and reduced risk of negative health outcomes,” says Jeremy Furtado, Sc.D., senior research scientist at Harvard T.H. Chan School of Public Health, who was not involved in the study.

An Objective Measure

This is not the first study to assess the connection between fish consumption and arterial health, but it is the largest to focus on PAD, and one of the only studies to test omega-3 levels in people’s fatty tissue.

The study authors point out that taking samples of adipose tissue (in this case from the buttocks) is one of the strongest ways to assess fish intake. Blood samples reveal levels of intake only in a short time period before the test.

“If a participant was on a high-fish diet right before they got a blood test, it might show a deceptively high level of omega-3s in their system,” says Furtado. “Testing the adipose tissue gives you a more holistic view of their diet for the previous year or two.”

This method of testing is also more objective than self-reported dietary studies, wherein participants tell researchers what they ate in a particular time period.

“It’s not like giving someone a dietary questionnaire and relying on their memory,” says Anne Lasota, M.D., one of the study’s authors. “This is an objective way to see how much fish someone has consumed over a significant period of time.”

Growing Evidence

Earlier this year, the American Heart Association reasserted its recommendations for fish intake: Have two servings of nonfried fish—especially fatty fish—per week. (A serving is 3½ ounces of cooked fish or ¾ cup of flaked fish.) These guidelines point to an increasing body of evidence showing lowered risk of cardiac death, strokes, and overall coronary heart disease from fish consumption.

Furtado—who recently co-authored a study showing connections between increased fish consumption and reduced risk of preterm births—points out that there hasn’t been a single study showing negative effects from eating fish. ”At worst, some studies have shown insignificant effects (from eating fish), but largely all the associations have been positive.”

It’s worth noting that new evidence shows that fish oil supplements may not have the same beneficial effects as eating whole fish. “Americans like to say, ‘What specifically is it about fish that gives me some benefit—give it to me in a pill,’” says Furtado. “The problem is, when you try to extract one specific nutrient out of fish, you remove other elements that may also be responsible for the positive health effects.”

Eating Fish May Mean a Healthier Lifestyle

Lasota notes that there may be other factors at play in why participants with the highest omega-3 levels in their tissue may have lower risk of developing PAD. For instance, participants who eat more fish may be living a healthier lifestyle generally, or just making more informed dietary choices.

Overall, Lasota believes her team’s research has a fairly strong takeaway. “It’s only one study, and we don’t want to be too broad in our conclusions,” she says. “But it’s pretty clear that eating fish—and fatty fish especially—is part of an overall healthier eating pattern.”