Omega-3 fatty acids from fish oil may help maintain the body's healthy response to inflammation, preventing the immune response from getting out of hand and leading to cardiovascular disease, according to a study conducted by researchers from Baylor College of Medicine and Harvard Medical School, and published in the Journal of the Federation of American Societies for Experimental Biology.

The researchers discovered that the blood vessels of many people have tendencies to form small lesions, even from a very young age. The normal healing process is for these lesions to become inflamed, for the inflammation to cool down, and then for the lesions to heal. In some cases, however, the inflammation appears to never cool, and the lesion never heals.

When the researchers intervened genetically to cause the body to produce more chemicals that encourage inflammation to cool, they found that blood vessels tended to heal themselves better. When they suppressed these signals, the inflammation and blood vessel damage quickly got out of hand.

"Resolution is not a passive process," researcher Lawrence C.B. Chan said. "It is active and produces specific anti-inflammatory mediators that 'cool down' the inflammatory process."

While some inflammation-cooling mediators are naturally produced by the body, others appear to function when ingested. One of these is the non-steroidal anti-inflammatory drug aspirin, which may account for its reported cardiovascular health benefits.

Another one, the researchers found, is omega-3 fatty acids, which are found in high quantities in fish oil and a few vegetable sources, such as flax seeds or certain algaes.

"Inflammation is a two-edged sword," lead author Aksam J. Merched said. "If resolution fails and the response gets out of hand, there is a never ending civil war in the body. Continued inflammation draws more macrophages [potent immune system cells] to the site of the inflammation. They produce molecules that turn this into a vicious cycle."