By Pat Anson, Editor

Taking fish oil supplements could help prevent lupus and other autoimmune diseases, according to animal studies at Michigan State University.

Researchers gave female mice genetically disposed to lupus an omega-3 fatty acid called DHA, or docosahexaenoic acid, which is found in fatty, cold-water fish. The findings, published in PLOS ONE, were “overwhelmingly positive,” according to researchers.

“What we discovered was when lupus was triggered by crystalline silica, a toxic mineral also known as quartz that’s linked to human autoimmunity, DHA blocked the activation of the disease,” said Melissa Bates, one of the study’s lead authors and a doctoral student in MSU’s Department of Food Science and Human Nutrition and the Institute of Integrative Toxicology.

Lupus is a genetic disease that can be triggered by inhaling crystalline silica and 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.

“Lupus is the body’s immune system attacking itself and it can damage any part of the body including skin, joints and organs,” said James Pestka, an MSU professor of food science and human nutrition.

The study looked at the effect of DHA on lupus lesions in the lungs and kidneys of laboratory mice.  

“Ninety-six percent of the lung lesions were stopped with DHA after being triggered by the silica,” said Jack Harkema, a pulmonary pathologist. “I’ve never seen such a dramatic protective response in the lung before.”

Harkema says the DHA could be changing the way lung cells, also known as macrophages, react to the silica and somehow alter the immune system’s response.

“Cells in the lung can gobble up the silica, but it’s so toxic, it kills these cells,” Harkema said. “When they 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.

“Our next step is to figure out exactly what’s happening,” he said.

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 is that DHA allows the cells to swallow up and remove the toxic silica from the lung without dying, preventing any inflammatory signals from being sent.

“What we do know is this study is a clear indication that eating DHA can prevent this one type of environmental triggering of lupus,” Pestka said. “It can suppress many of the disease’s signaling pathways, which current drugs on the market now try to target and treat.”

The National Institute for Environmental Health Sciences and the Lupus Foundation of America funded the MSU research.

DHA is produced by the algae that cold water fish eat and store in their bodies. It can also be found in fish oil supplements, which are used by more than 30 million Americans.

Previous studies have found that fish oil lowers an inflammatory response associated with autoimmune diseases. Fish oil may also help prevent cardiovascular disease and hypertension, although consuming large amounts of it may increase the risk of internal bleeding or stroke.