Omega-3 fatty acid can suppress lupus, autoimmune disorders

Consuming an omega-3 fatty acid called DHA, or docosahexaenoic acid commonly found in fatty, cold-water fish, has the potential to suppress signalling pathways of lupus as well as other autoimmune disorders, researchers have found.

Lupus is an inflammatory disease caused when the immune system attacks its own tissues and it can damage any part of the body including skin, joints and organs.

The study found that when lupus was triggered by crystalline silica, a toxic mineral also known as quartz that is linked to human autoimmunity, DHA blocked the activation of the disease.

The preclinical study, conducted by researchers from the Michigan State University, in the US, looked at the effect of DHA on lupus lesions in the lungs and kidneys of female mice that were already genetically predisposed to the disease. Their results were overwhelmingly positive.

"Ninety-six per cent of the lung lesions were stopped with DHA after being triggered by the silica," said Jack Harkema, pathologist at the Michigan State University.

Lupus is considered a genetic disease and is triggered not only by inhaling crystalline silica toxicants, but also by other environmental factors such as sun exposure.

Quartz is the most common, and most dangerous, form of crystalline silica and is often found in the agriculture, construction and mining industries where workers can breathe in the mineral dust.

"Cells in the lung can gobble up the silica, but it's so toxic, it kills these cells. When these cells die, signals are sent out to the immune system that something is wrong. The body then produces such a strong response that it also starts to target healthy cells," Harkema said.

According to Harkema, the DHA could be changing the way these cells, also known as macrophages, react to the silica in the lungs and somehow alter the immune system's response.

One theory is the DHA helps cells send an anti-inflammatory signal to the body so it doesn't overcompensate and trigger an autoimmune response. Another thought is somehow the DHA allows the cells to swallow up and remove the toxic silica from the lung without dying, preventing any inflammatory signals from being sent, the researchers explained.

"The study is a clear indication that eating DHA can prevent this one type of environmental triggering of lupus. It can suppress many of the disease's signalling pathways, which current drugs on the market now try to target and treat," Pestka said in the findings published in PLOS ONE.