Lupus: Mouse Study Finds DHA Reduces Lung and Kidney Damage
Lupus: DHA reduces lung and kidney lesions in mice
Omega-3s omega 3 may counteract Systemic Lupus Erythematosus, a chronic autoimmune disease that mainly affects young women. According to a study conducted on laboratory mice, DHA reduces lung and kidney lesions by over 90% in affected animals. A surprising result that suggests new hypotheses about the role of omega-3s in fighting autoimmune diseases.
The details of the research, conducted by researchers from the University of Michigan (USA), were published in the journal PLOS One.
What is Systemic Lupus Erythematosus?
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease affecting one person every 5,000 inhabitants; in Italy there are about 60,000 patients. Most affected are women of childbearing age, with a frequency 10 times higher than men. Although lupus is a disease that, like few others, can cause manifestations affecting any organ or system, there are some clinical manifestations characteristic of the disease, such as skin alterations, arthritis, pleurisy and pericarditis, kidney damage, and hematological abnormalities.
The cause of SLE is unknown, however it is believed that the disease is caused by genetic predisposition and one or more external triggering factors, such as certain drugs, infections, severe trauma or stress, hormonal alterations, prolonged exposure to sunlight or UV rays, and certain substances.
Among these, crystalline silica particles, commonly called quartz, to which workers involved in mining extraction are exposed, seem to increase the risk of developing autoimmune diseases including SLE. Another factor that appears to influence susceptibility to autoimmunity is diet, particularly lipids which are nutrients that can affect immune system function.
Polyunsaturated omega-3 and omega-6 fatty acids are, respectively, precursors of pro-inflammatory and anti-inflammatory molecules. Clinical studies over the last 30 years have revealed that omega-3 intake prevents and resolves inflammation and, consequently, could help those genetically predisposed to counter autoimmune diseases such as SLE.
Less lung and kidney damage thanks to algal DHA
The research studied the effect of different concentrations of the omega-3 DHA, extracted from certain marine algae, on lung and kidney lesions caused by Lupus in laboratory mice. Results revealed that up to 96% of these lesions were reduced with high concentrations of DHA. As emphasized by Dr. James Pestka, professor at Michigan State University and lead author of the study, since produced in a controlled environment, the oil extracted from algae rich in DHA contained no environmental contaminants, making it a safe product. However, if obtained through specific processing methods, omega-3s derived from fish can also be free from pollutants.
These results highlight the need to consume fish rich in omega-3 or specific supplements; these fatty acids, which humans are unable to synthesize, are poorly represented in the Western diet, which is instead rich in saturated fats or omega-6 polyunsaturated fatty acids.
Some study details
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%.
Two weeks after the treatment, the mice were exposed to 1 mg of quartz, a mineral substance which, as mentioned, stimulates autoimmune responses in the kidneys and lungs, once a week for 16 weeks. After the treatment ended, concentrations of inflammation and autoimmunity signaling molecules were analyzed in the lungs, kidneys, and blood. Results showed that in the lungs, the amount of some antibodies had decreased following the consumption of the different DHA concentrations: 0.4; 1.2; 2.4%, respectively by 80, 98 and 96%.
Supplementation with the same DHA concentrations also caused reductions of immune cells (CD3+) in the lungs by 41, 79 and 83%, respectively. According to one of the study’s authors, Jack Harkema, DHA might modify how certain immune system cells, also known as macrophages, respond to silica by improving immune response in the lungs. Commenting on the results, Harkema noted that such a large effect of DHA on silica-induced lung lesions has never been shown before in other studies.
DHA as a future therapy?
The results indicate 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. Supporting this hypothesis, it should be noted that quartz exposure also seems linked to another autoimmune disease: Rheumatoid Arthritis, and some research has shown that omega-3 consumption is beneficial for those affected. However, the study, as researchers pointed out, was conducted only on animals; in humans, the DHA doses comparable to those used on mice would be about 2, 6 and 12 grams per day. The current recommendations set by the European Food Safety Authority (EFSA) suggest a daily intake of 250 milligrams of EPA + DHA for the general adult population and a maximum tolerated amount of 5 grams per day. Future studies will need to 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.
