Earlier studies of the Inuit living in Arctic regions provided evidence that people consuming a diet dominated by omega-3 fats had vastly lower rates of myocardial infarction compared to people living in developed countries.2 They also had a lower frequency of autoimmune and inflammatory diseases, yet as much as a 60% higher rate of apoplexy, Dr. Cleland said.
‘Why should we be interested in acute inflammation & its resolution in the realm of a chronic disease like RA?’ —Derek W. Gilroy, PhD
“The diet of the Inuit in their aboriginal state consists of sea mammals, fish and sea birds. The omega-3 fatty acids found in these marine vertebrates have their origins in the sea algae that these animals eat,” he said. Although an omega-3-rich diet can positively affect serum lipids, cholesterol and high blood pressure, key drivers of cardiovascular disease, “as for anti-thrombosis, the effect of omega-3 fats is relatively modest.”
In a 2011 study published in Cardiology, people given fish oil after coronary artery bypass grafting surgery did not have statistically significant delayed time of onset to atrial fibrillation, an irregular heartbeat that can raise stroke risk, but did spend significantly less time in the intensive care unit after surgery, he said.
Fish oil’s potential benefits as an inflammatory mediator could be jeopardized by the sustainability of the world’s fish supply, so metabolic engineering of plant seeds, such as rapeseed, to achieve levels of DHA similar to fish oil, may help fill the need, said Dr. Cleland. “Fish oil has a place in the treat-to-target management of RA, and GMO crops may have a future role.”
Road to Resolution
After an acute infection or injury, inflammation kicks in for a quick immune response. Polymorphonuclear cells like neutrophils and eosinophils migrate to affected tissue within hours to attack bacteria. A clean-up crew of macrophages then move in to sweep out whatever is left, preparing the tissue for homeostasis and resolution.
“Why should we be interested in acute inflammation and its resolution in the realm of a chronic disease like RA?” said Dr. Gilroy. Understanding how mediators behave in self-limiting inflammation may tell us more about what may go wrong in other situations.
Resolution is not the final chapter of acute inflammation, and resolution of inflammation amplifies adaptive immunity, he said. In a 2014 study published in Blood, mice were infected to cause peritonitis and then treated with 10 g of zymosan.3 Dr. Gilroy and his fellow researchers found that even after resolution of the inflammation within 72 hours, a second wave of leukocytes entered the peritoneal cavity and persisted for weeks. Tissues do not revert back to the state they were before inflammation, but instead are in a state of adapted homeostasis, which may intensify future inflammatory responses, he said.
