Types of fish consumed affects heart

A diet rich in baked or broiled fish, especially dark-fleshed varieties, is linked to a lower risk of heart failure in older women.

A study, reported in Circulation: heart failure, the risk of developing heart failure, showed heart failure was lower for postmenopausal women who frequently ate baked or broiled fish, but higher for those who ate fried fish.

In a large-scale analysis, women who ate the most baked or broiled fish (five or more servings per week) had a 30% lower risk of heart failure compared to women who seldom ate it (less than one serving per month).

This study also showed the type of fish and cooking method may affect heart failure risk.

The researchers found dark fish (salmon, mackerel and bluefish) were associated with a significantly greater risk reduction than tuna or white fish (sole, snapper and cod).

In a similar analysis, eating fried fish was associated with increased heart failure risk. Even one serving a week was associated with a 48% higher heart failure risk.

Senior author of the study, Donald Lloyd-Jones, said not all fish were equal, and “how you prepare it really matters”.

“When you fry fish, you not only lose a lot of the benefits, you likely add some things related to the cooking processes that are harmful,” Mr Lloyd-Jones said.

“In this case, we demonstrated that eating fish is associated with heart failure prevention. This suggests fish is a very good source of lean protein that we ought to be increasing as a proportion of our diet and decreasing foods that contain less healthy saturated and trans fats,” he said.

Other research showed fried food increased the trans fatty acid (TFA) content of foods, which is associated with the increasing risk for heart disease.

Mr Lloyd-Jones and his team examined self-reported dietary data from 84,493 postmenopausal women. They then divided study participants based on the frequency and type of fish consumption.

Two groups of fish intake were defined: baked/broiled or fried fish. The baked/broiled fish group consisted of canned tuna, tuna salad, tuna casserole, white fish (broiled or baked), dark fish (broiled or baked) and shellfish (not fried).

The fried fish group consisted of fried fish, fish sandwiches and fried shellfish.

Researchers conducted their analysis based on data from 1991 through August 2008.

During an average follow-up of 10 years, about 1,858 cases of heart failure occurred.

About 85% of the participants were Caucasian, 7% African-American and 3% Hispanic. Their average age was 63 years old.

Older participants whose diets included more baked/broiled fish tended to be healthier and younger than their counterparts who ate fried fish.

The results of this study are consistent with previous findings in studies of older American and Swedish populations, but the new study added the interesting results about consuming darker fish.

Previous research has found fatty acids (omega-3) in fish — EPA, DHA and ALA — may lower the risk of cardiovascular disease by decreasing inflammation, resisting oxidative stress and improving blood pressure, cardiac and blood vessel function.