Folks with a family history of heart disease might benefit from eating more oily fish like salmon, mackerel, herring and sardines, a new study finds.

Oily fish contain high levels of omega-3 fatty acids, which cannot be produced by the body and must be obtained from the diet.

People’s risk of heart disease increased by more than 40% if they had low levels of omega-3 fatty acids plus a family history of heart problems, a large international study concluded.

However, if a person has adequate levels of omega-3 fatty acids, their family heart history increased their risk by just 25%.

The results show that heathy habits can overcome genetic risk in some cases, researchers said.

“The study suggests that those with a family history of cardiovascular disease have more to gain from eating more oily fish than others,” said lead researcher Karin Leander, an associate professor of epidemiology at the Karolinska Institute in Sweden.

Omega-3 fatty acids have been linked to a stronger immune system, reduced inflammation, lower blood pressure and improved cholesterol counts, according to the American Heart Association.

For the study, Leander and her colleagues pooled data from more than 40,000 people, nearly 8,000 of whom developed heart problems like unstable angina, heart attack, cardiac arrest and stroke.

Levels of omega-3 fatty acids were measured in all study participants. These levels are a reliable measure of a person’s dietary intake of oily fish, and more trustworthy than people’s self-reported diet data, Leander said.

“The fact that the measurements of fatty acids in blood and tissue are objective, as opposed to self-reported data on eating habits, is an important advantage,” she noted in an institute news release.

Researchers analyzed each person’s family history and omega-3 levels, and found that the fatty acids appeared to lower the overall risk for heart disease.

The study was published Dec. 4 in the journal Circulation.

“Cardiovascular disease is to some extent hereditary, as shown by twin studies, but it has been difficult to identify the controlling genes,” Leander said. “A strong hypothesis is therefore that it is a combination of genetics and environment.”

More information

The American Heart Association has more on omega-3 fatty acids and heart health.

SOURCE: Karolinska Institute, news release, Dec. 4, 2023