High doses of omega-3 fatty acids from fish oil can aid recovery from a heart attack, say scientists.
Taking omega-3 improves heart function and reduces scarring in undamaged cardiac muscle, results from a clinical trial have shown.
After a heart attack, the heart's shape and function may be "remodelled" in ways that lead to a poorer prognosis for the patient and increase the risk of heart failure.
Heart attack patients taking part in the trial were given either a 4g daily dose of omega-3 fatty acids for six months or a placebo.
Those taking omega-3 experienced a 5.8% reduction in left ventricular end-systolic volume index, a clinical marker which predicts heart attack patient outcomes.
They also had a 5.6% lower indication of scarred connective tissue formation in non-damaged heart muscle.
Lead researcher Dr Raymond Kwong, from Brigham and Women's Hospital in Boston, US, said: "Heart failure is still a major problem after a heart attack despite all the therapy we have and the advances in interventional care.
"Our findings show that omega-3 fatty acids are a safe and effective treatment in improving cardiac remodelling, so it may be promising in reducing the incidence of heart failure or death, which are still major healthcare burdens to patients who suffer a heart attack."
The results, published in the journal Circulation, suggest that omega-3 fatty acids allow the heart to contract more efficiently and reduce scarring, said the scientists.
There were also signs that the fish oil fats were reducing inflammation in the heart.
The study involved 360 patients who were treated within a month of suffering a heart attack.