A diet rich in omega-3 fatty acids helps keep the DNA of heart patients from unraveling, which may help explain why fish oil is so beneficial after a heart attack.
Omega-3 fish oil is known to be beneficial for patients with coronary heart disease. A number of studies in the past have shown taking fish oil through diet or supplements after heart attack reduces the risk of a subsequent heart attack or death from coronary heart disease. But why fish oil is so beneficial has not been clear. So, the researchers looked at mechanisms by which omega-3 fatty acids work and benefit the heart.
For the study, the researchers focused on telomere length - the length of protective caps on the ends of chromosomes that carry DNA. Shortening of these protective caps can lead to premature aging and cancer. The researchers measured the length of telomeres in blood cells in 608 American heart attack patients to see if there was any association between the levels of omega-3 fatty acids and the change in telomere length over time.
Increasing levels of the amount of omega-3 fish oil in the blood was found to be associated with a decrease in the rate of biological aging. Those with the highest levels of omega-3 fatty acids had the longest telomeres, while patients with low levels of the compounds had shorter telomeres. None of the patients were given supplements and the researchers did not collect dietary information, so it is not clear just how much fish oil it took to have an effect. While fish oil is a primary source of omega-3 fatty acids, they are also found in walnuts, flaxseed oil and leafy green vegetables.
The findings explain why fish oil helps heart patients, and this may be attributed to the fact that omega-3 fatty acids counteract oxidative stress - a cell-damaging chemical reaction that can shorten telomeres. Fish oil could also increase the production of telomerase - an enzyme that lengthens and repairs shortened telomeres.