New research from the University of Virginia School of Medicine explains why obesity causes harmful inflammation that can lead to type 2 diabetes and other health problems.
With this knowledge, the hope is that researchers will be able to find ways to reduce inflammation and consequently fight disease.
In the breakthrough, researchers were able to explain why resident immune cells in fat tissue (cells that are thought to be beneficial) turn harmful during obesity, causing unwanted inflammation.
Norbert Leitinger, Ph.D. and his team at UVA’s Department of Pharmacology, found that damaging “free radicals” produced within our bodies react with substances known as lipids inside fat tissue. This attack on the lipids prompts them to cause inflammation, a natural immune response.
“Free radicals are so reactive that they want to hitch onto something,” explained co-researcher, Vlad Serbulea, Ph.D. in a press release. “Lipids happen to be a very good sink for these radicals to combine with,” he adds.
That results in a process called “lipid oxidation.” Some of the oxidized lipids were causing damaging inflammation and other oxidized lipids were present in healthy tissue. Specifically, they found that shorter ones were protective, while longer ones were inflammatory.
“When we compare healthy and obese tissue, what seems to change is the ratio of full-length and truncated oxidized lipids,” Serbulea says. “Our studies show that the full-length, or longer, oxidized lipids are quite inflammatory. They promote inflammation within these immune cells, and we think that instigates and perpetuates the disease process within [fat] tissue during obesity.”
What Does This All Mean?
Now that scientists know which oxidized lipids are causing problems, they can seek to block them to prevent inflammation. They may be able to develop a drug, for example, that would reduce the number of harmful, full-length oxidized lipids.
“Now, knowing that some of these molecules are really bad guys, so to speak, eliminating them from the circulation may have a very beneficial effect on chronic diseases,” says Leitinger.
Alternately, doctors might want to promote the number of beneficial, shorter phospholipids. “Inflammation is important for your body’s defenses, so you don’t want to eliminate it completely,” Leitinger notes. “It’s a question of finding the right balance.”