Lupus: mouse study reveals DHA reduces lung and kidney injury
Lupus: DHA reduces lung and kidney injury in mice
Omega-3s could counteract Systemic Lupus Erythematosus, a chronic autoimmune disease that mainly affects young women. In fact, according to a study in laboratory mice, DHA reduces lung and kidney lesions that occur in affected animals by more than 90 percent. A surprising result that suggests new hypotheses about the role of omega-3s in combating autoimmune diseases.
Details of the research, conducted by researchers at the University of Michigan (United States), have been published in the journal PLOS One.
What is systemic lupus erythematosus?
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects one person in every 5,000 inhabitants; about 60,000 patients would be affected in Italy. Mostly women of childbearing age are affected, occurring 10 times more frequently than men. Although lupus is a disease that, like few others, can give manifestations affecting any organ or apparatus, there are some clinical manifestations that are characteristic of the disease, such as skin changes, arthritis, pleurisy and pericarditis, kidney damage, and hematologic changes.
The cause of SLE is unknown; however, it is believed that genetic predisposition and one or more external triggers, such as certain medications, infections, severe trauma or stress, hormonal changes, prolonged exposure to sun or UV rays, and certain substances, determine the disease.
Among the latter, particles of crystalline silica, commonly called quartz, to which workers employed in mining are exposed, appear to increase the risk of onset of autoimmune diseases including SLE. Another factor that appears to determine susceptibility to autoimmunity is diet, particularly lipids, which are the nutrients that can influence immune system function.
Omega-3 and omega-6 polyunsaturated fatty acids are, respectively, the precursors of pro-inflammatory and anti-inflammatory molecules. Clinical studies over the past 30 years have revealed that ingestion of omega-3 prevents and resolves inflammation and, as a result, could help those individuals who have a genetic predisposition to counteract malimmune diseases such as SLE.
Less lung and kidney injury thanks to algal DHA
The research studied the effect of different concentrations of omega-3 DHA, extracted from certain seaweeds, on lung and kidney lesions caused by Lupus in laboratory mice. The results revealed that up to 96 percent of these were reduced with high concentrations of DHA. As pointed out by Dr. James Pestka, professor at Michigan State University and lead author of the study, because it was produced in a controlled environment, the oil extracted from the DHA-rich algae did not count environmental contaminants, making it a safe product. But if obtained by specific processing, even omega-3s derived from fish can be free of contaminants.
The results are a reminder of the need to consume omega-3-rich fish or specific supplements; these fatty acids, which humans are unable to synthesize, are underrepresented in the Western diet, which is rich instead in saturated fats or omega-6 polyunsaturated fatty acids.
Some details of the study
The study examined the effect of DHA on typical SLE lesions in the lungs and kidneys of female mice genetically predisposed to the disease. The animals were fed diets containing different concentrations of DHA: 0.0; 0.4; 1.2 and 2.4 percent.
Two weeks after treatment, the mice were then exposed to 1 mg of quartz, a mineral substance that, as mentioned, stimulates the autoimmune response in kidneys and lungs, once a week for 16 weeks. After the treatment ended, concentrations of signal molecules of inflammation and autoimmunity were analyzed in lungs, kidneys and blood. The results revealed that in the lungs, the amount of certain antibodies had been reduced following consumption of the different concentrations of DHA: 0.4; 1.2; 2.4 percent, by 80, 98 and 96 percent, respectively.
Supplementation of the same concentrations of DHA also caused the reduction of immune cells (CD3+) in the lung by 41, 79 and 83 percent, respectively. According to one of the study's authors, Jack Harkema, DHA could change the way some immune system cells, also known as macrophages, respond to silica by enhancing the immune system response in the lungs. Commenting on the results, Harkema himself pointed out that such a large effect of DHA on lung injury, triggered by silica, has never been shown before in other studies.
DHA as a future therapy?
The results obtained point to DHA as a candidate for the prevention or treatment of chronic inflammatory diseases, as it can block the progression of autoimmune conditions triggered by environmental factors. To confirm this hypothesis, it should be mentioned that exposure to quartz also seems to be linked to another autoimmune disease: Rheumatoid Arthritis, and, some research has shown that omega-3 consumption is beneficial for those affected. The study, however, as the researchers pointed out, was conducted only on animals; in humans, doses of DHA correlated to those used on mice would be about 2; 6 and 12 grams per day. Current recommendations set by the European Food Safety Authority (EFSA), however, suggest an intake of 250 milligrams of EPA + DHA per day for the general adult population and a maximum tolerated amount of 5 grams per day. Future studies, therefore, should focus on the effect of this dose, or lower doses, of omega-3 in humans.
Source: Authors: James J. Pestka et al. "Silica-Triggered Autoimmunity in Lupus-Prone Mice Blocked b y Docosahexaenoic Acid Consumption." PLOS One.
