Why Fish Oils Help With Conditions Like Rheumatoid Arthritis
How They Could Help Even More

ScienceDaily -- New research from Queen Mary, University of London and Harvard Medical School has revealed precisely why taking fish oils can help with conditions like rheumatoid arthritis.

In a paper published in Nature October 28, researchers describe how the body converts an ingredient found in fish oils into another chemical called Resolvin D2 and how this chemical reduces the inflammation that leads to a variety of diseases.

The research also suggests that Resolvin D2 could be the basis for a new treatment for diseases including sepsis, stroke and arthritis. Unlike other anti-inflammatory drugs, this chemical does not seem to suppress the immune system.

The researchers, who were funded by the Arthritis Research Campaign, the Wellcome Trust and the National Institutes of Health, looked at a particular ingredient of fish oils called DHA. They were able to show how the body converts DHA* into Resolvin D2 and discover its exact chemical structure.

Mauro Perretti, Professor of Immunopharmacology at Queen Mary, University of London, led the UK team. He said: "We have known for some time that fish oils can help with conditions like arthritis which are linked to inflammation. What we've shown here is how the body processes a particular ingredient of fish oils into Resolvin D2. We've also looked in detail at this chemical, determining at least some of the ways it relieves inflammation. It seems to be a very powerful chemical and a small amount can have a large effect."

"This research is important because it explains at least one way in which fish oils can help in different types of arthritis. We can also work on this chemical and see if it can be used not only to treat or even prevent arthritis, but also as a possible treatment for a variety of other diseases associated with inflammation."

Arthritis, and many other diseases, are caused by inflammation. This means that the body's natural defences against infections are mistakenly directed at healthy tissue.

Previous research has shown that a crucial step in this process occurs when white blood cells, called leukocytes, stick to the inner lining of the blood vessels, called the endothelium.

Researchers studied these blood cells and how they interact with the endothelium in the lab. When they added Resolvin D2 they found that the endothelial cells produced small amounts of nitric oxide, which acts as a chemical signal discouraging the white blood cells from sticking to the endothelial cells and preventing inflammation.

Fish Oil May Protect Against Stroke From Ruptured Carotid Artery Plaques

ScienceDaily (Nov. 1, 2009) -- Research led by Hernan A. Bazan, MD, Assistant Professor of Surgery, Section of Vascular Surgery, at LSU Health Sciences Center New Orleans School of Medicine, has found that unstable carotid artery plaques -- those in danger of rupturing and leading to a stroke -- contain more inflammation and significantly less omega-3 fatty acids than asymptomatic plaques.

This suggests that increasing the levels of omega-3 fatty acids in carotid artery plaques could either prevent strokes or improve the safety of treatment. This may be accomplished by increasing dietary intake of foods rich in omega-3 fatty acids. The study is an Article in Press in the journal, Vascular Pharmacology, currently online.

Our bodies produce only a small amount of omega-3 fatty acids, so most of what we need has to come from eating omega-3 fatty acid-rich foods like fish (salmon, tuna, trout, herring, etc.) or from supplements. Omega-3 fatty acids have been shown to protect against cardiovascular disease, particularly heart attack and sudden cardiac death. Dr. Bazan's team wanted to determine what the association might be with plaques in the carotid arteries, a common cause of strokes. Vulnerable plaques which can rupture in the carotid arteries may lead to transient ischemic attacks (TIAs), strokes, or vision loss by affecting the artery to the retina. The mechanisms leading to plaque rupture are still not fully understood but inflammation within the plaque is beginning to be recognized as an important cause of plaque rupture.

Dr. Bazan, an LSUHSC vascular/endovascular surgeon, in collaboration with researchers at Yale University and others at LSUHSC, analyzed plaques from 41 patients who underwent carotid endarterectomy (CEA) to remove plaque buildup in their arteries. Twenty-four patients were asymptomatic and 17 were symptomatic, having had neurological symptoms. All of the fats in the plaques were assessed with mass spectrometry, in collaboration with Dr. Song Hong at LSUHSC. The team was measuring the amounts of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) -- the components of long-chain omega-3 polyunsaturated fatty acids. The plaques of asymptomatic patients contained more than twice as much DHA as the symptomatic patients, and about one and a half times as much EPA. Significantly less inflammation was also seen in the carotid atherosclerotic plaques from asymptomatic patients.

"In the future, a study to address whether supplementation with dietary omega-3 polyunsaturated fatty acids prevents carotid-related events in patients with moderate or high-grade carotid stenosis will help answer whether this is a formidable therapeutic target for the prevention of stroke," says Dr. Bazan.

According to the Centers for Disease Control and Prevention, stroke is the third leading cause of death in the United States, as well as a leading cause of serious long-term disability. About 795,000 strokes occur in the US each year and about 610,000 of these are first, or new, strokes. About 185,000 occur in people who have already had a stroke. Nearly 25% of strokes occur in people under the age of 65. Of all ischemic strokes occurring, carotid artery atherosclerotic plaques account for over a third of them. It has been noted for several decades that the southeastern United States has the highest stroke mortality in the country. It is not completely clear what factors might contribute to the higher incidence and mortality from stroke in this region.

The research was supported by the National Institutes of Health-National Center for Research Resources, an LSUHSC Cardiovascular Center Grant ("Mentoring in Cardiovascular Biology"), and the American Vascular Association.

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