Press Association
Saturday 11th February 2012
Scientists believe they have unlocked the secret of how fish oil helps prevent diabetes and heart disease.
Understanding the anti-inflammatory mechanism could lead to new dietary remedies and novel drugs.
Omega-3 fatty acids found in oily fish such as sardines and mackerel are said to have a wealth of health-giving properties.
Research suggests they reduce the risk of chronic conditions such as Type-2 diabetes, heart disease and arthritis. There is also growing evidence that they combat cancer and stave off dementia. These effects have been put down to omega-3's ability to control inflammation, an immune response that can get out of control.
Scientists in the US carried out studies on mice which showed how omega-3 interacts with macrophages - specialised white blood cells that engulf and digest cellular debris and harmful molecules.
Macrophages secrete proteins that trigger inflammation. But omega-3 was found to latch onto a switch-like "receptor" on macrophage cells and stop this happening.
When the GPR120 receptor is turned "off", the macrophage produces inflammatory effects. Omega-3 switches the receptor "on" causing a chain of biochemical events that lead to inflammation shutting down.
Professor Jerrold Olefsky, from the University of California at San Diego, said: "It's just an incredibly potent effect. The omega-3 fatty acids switch on the receptor, killing the inflammatory response.
"This is nature at work. The receptor evolved to respond to a natural product - omega-3 fatty acids - so that the inflammatory process can be controlled. Our work shows how fish oils safely do this, and suggests a possible way to treating the serious problems of inflammation in obesity and in conditions like diabetes, cancer and cardiovascular disease through simple dietary supplementation."
The research is published in the journal Cell.
