Fish oil has long been promoted for its role in brain and heart health. Now, scientists have a clearer picture of how the omega-3 fatty acids in fish oil work to reduce chronic inflammation in diabetes patients.
Chronic inflammation can lead to insulin resistance, a condition that is often a precursor to Type 2 diabetes. Insulin resistance occurs when the body's insulin can no longer properly regulate blood sugar levels.
"People always knew [omega-3 fatty acids] were good and they suspected they were anti-inflammatory, but we defined the mechanism a bit better," said study researcher Saswata Talukdar, of the University of California - San Diego.
Inflammation can result from white blood called macrophages secreting proteins called cytokines to destroy harmful pathogens. In obese people, there is a high number of macrophages, so they tend to have more cytokines. The macrophages' neighboring cells are overexposed to those cytokines, leading to insulin resistance.
This is where omega-3 acids step in.
Omega-3 fatty acids activate a certain receptor on macrophages, creating an anti-inflammatory effect, Talukdar said.
"It's conceivable that since diabetes or insulin resistance is an inflammatory resultant disease, we can reasonably assume that if a patient who is inflamed were to take [omega-3 fatty acids] they might have a beneficial effect," he said.
There are 23.6 million people in the United States with diabetes, with 1.6 million new adult cases diagnosed each year, according to the American Diabetes Association.
Talukdar and other scientists worked with obese lab mice to find the results. Some mice had been genetically modified to lack the macrophage receptor, and those did not respond to omega-3 fatty acid supplements. Other mice that had the receptor responded favorably to the supplements, and their inflammation was inhibited.
"It is reasonable to assume that if the study were conducted in humans, it would yield a similar pattern," Talukdar said. "The next step would be to see what happens in patients and to see [if] omega 3s actually prevent onset of diabetes."
The study was published in the Sept. 3 issue of the journal Cell.