Fish oil may be able to slow down biological ageing by extending the genetic "fuse" that controls how long cells survive, according to a study of heart disease patients.
The omega-3 fatty acids found in fish oil have been claimed to reduce heart disease, improve survival after a heart attack, slow mental decline and protect the eye from age-related changes that can cause blindness.
Although the mechanisms behind omega-3's anti-inflammatory properties are not well understood, scientists said the fatty acids appear to slow down the shortening rate of protective caps at the end of chromosomes.
British Heart Foundation senior cardiac nurse, June Davison, said: "This is an interesting study which may offer a further explanation as to why a dietary intake of omega-3 fats from fish can help to protect your heart.
"It is well established that a dietary intake of omega-3 is good for heart health. Oily fish, such as salmon, mackerel or sardines, is a nutritious source of omega-3.
"Current UK guidelines state that the general population should have two portions of fish a week, one of which should be oily. Those who have had a heart attack should have two to three portions of oily fish a week."