Omega-3 help prevent lupus

A team of Michigan State University researchers has found that consuming an omega-3 fatty acid called DHA, or docosahexaenoic acid, can stop a known trigger of lupus and potentially other autoimmune disorders.

DHA can be found in fatty, cold-water fish and is produced by the algae that fish eat and store in their bodies. It can be found in fish oil supplements as well, used by more than 30 million Americans.
"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.
The findings have been published in PLOS ONE.
The preclinical study 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 percent of the lung lesions were stopped with DHA after being triggered by the silica," said Jack Harkema, another study author and pulmonary pathologist. "I've never seen such a dramatic protective response in the lung before."
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.
"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, a University Distinguished Professor of food science and human nutrition, who also co-led the research with Bates and Harkema.
Although it's still unknown exactly why DHA is able to prevent the onset of lupus, the researchers said this study provides scientists with a better model for looking at just how much DHA is needed to ward off the environmental trigger of the disease.
"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."
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.
"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 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.
"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."

---

Story Source:
Materials provided by Michigan State University. Note: Content may be edited for style and length.

---

Journal Reference:

1. Melissa A. Bates, Christina Brandenberger, Ingeborg I. Langohr, Kazuyoshi Kumagai, Adam L. Lock, Jack R. Harkema, Andrij Holian, James J. Pestka. Silica-Triggered Autoimmunity in Lupus-Prone Mice Blocked by Docosahexaenoic Acid Consumption. PLOS ONE, 2016; 11 (8): e0160622 DOI: 10.1371/journal.pone.0160622

 

A new study suggests that docosahexaenoic acid - a type of omega-3 present in fish oil and dietary supplements - has the potential to prevent lupus, after finding the fatty acid blocked a known trigger of the disease.

Researchers suggest the omega-3 fatty acid DHA could prevent lupus triggered by exposure to crystalline silica.

In the journal PLOS One, researchers report how docosahexaenoic acid (DHA) stopped crystalline silica - a toxic mineral associated with the development of systemic lupus erythematosus (SLE) - from causing lung lesions in mice genetically predisposed to lupus.
Lupus is an autoimmune disease estimated to affect around 1.5 million people in the United States.
In lupus, the immune system mistakenly attacks and destroys healthy tissues, cells, and organs, causing pain and inflammation.
SLE is the most common form of the disease, accounting for around 70 percent of all cases. Skin is the organ most often affected by SLE, though the brain, kidneys, lungs, and other organs and tissues can also be damaged.

Crystalline silica and lupus

There are a number of environmental factors believed to trigger lupus in individuals vulnerable to the condition, one of which is exposure to crystalline silica.
Crystalline silica is a natural compound present in numerous substances, including concrete, brick, and mortar. It was classed as a carcinogen, after studies showed that exposure to small, airborne particles of the compound raised the risk of lung cancer.
Previous research has also associated occupational exposure to crystalline silica with increased risk of SLE and other autoimmune diseases, with damage to the lungs in particular.
"Cells in the lung can gobble up the silica, but it's so toxic, it kills these cells," explains study co-author Jack Harkema, of the Institute for Integrative Toxicology at Michigan State University.
"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."

DHA prevented 96 percent of lung lesions in silica-exposed mice

Harkema and colleagues set out to investigate whether DHA might offer some protection against the toxic effects of crystalline silica, based on knowledge that the omega-3 fatty acid has anti-inflammatory properties.
DHA is one of the three main forms of omega-3. Present in dietary supplements and fatty fish - such as salmon, tuna, and trout - DHA is considered key for brain development and function.
For their study, the researchers used female mice that were genetically predisposed to develop lupus.
The mice were randomized to one of four diets: a diet containing either 0.4 percent, 1.2 percent, or 2.4 percent DHA, or a control diet. The DHA diets were equivalent to human diets containing 2, 6, or 12 grams of DHA daily.
After 2 weeks, all groups were exposed to 1 milligram of crystalline silica once weekly for 4 weeks. They remained on the experimental diets for a further 12 weeks.
On assessing the rodents' lungs, the researchers found that the mice which were fed the 1.2 percent, or 2.4 percent DHA diets had significantly fewer lung lesions than mice which received the control diet.
"Ninety-six percent of the lung lesions were stopped with DHA after being triggered by the silica," notes Harkema. "I've never seen such a dramatic protective response in the lung before."
The 0.4 percent diet appeared to have no effect on lung lesions, the team reports.

'Clear indication' that DHA can prevent silica-induced lupus

The researchers are unable to pinpoint precisely how DHA might prevent crystalline silica-induced lesions, but they speculate that the fatty acid could be altering the way lung macrophages - a type of white blood cell involved in the detection and destruction of harmful pathogens - react to the toxic substance.
"Our next step is to figure out exactly what's happening," says Harkema.
Still, the researchers say their current findings shed some much-needed light on ways to prevent lupus.

"What we do know is this 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 signaling pathways, which current drugs on the market now try to target and treat."

Study co-author James Pestka, Michigan State University

Read about a study that suggests omega-3 and omega-6 fatty acids may improve reading skills.

Written by Honor Whiteman