Much of the focus on blood lipid levels is on cholesterol, as higher levels of cholesterol mean higher levels of the oxidized cholesterol that causes atherosclerosis, the formation of fatty lesions that narrow and weaken blood vessels. Methods of lowering cholesterol, such as statins, can slow the progression of atherosclerosis to some degree and reduce risk of a consequent stroke or heart attack occurring when an atherosclerotic lesion ruptures. Researchers here look instead at consequences of high triglyceride levels in the blood, uncovering a mechanism by which this provokes chronic inflammation. Since inflammation drives the progression of all of the common conditions of aging, atherosclerosis included, ways to lower triglyceride levels should also be an area of interest.
It has been known for some time that certain fat molecules in our bloodstream can trigger an inflammatory response. Patients with higher levels of these fats in their blood have a significantly greater chance of dying early from kidney damage or vascular disease. Now a research team was able to show how these fat molecules interact with body cells and how they can mobilize the body's own immune system to damaging effect.
"Our work has involved studying a special group of lipids, the triglycerides. We've been able to show that when these naturally occurring fats are present at elevated concentrations they can alter our defense cells in such a way that the body reacts as if responding to a bacterial infection. This leads to inflammation, which, if it becomes chronic, can damage the kidneys or cause atherosclerosis - the narrowing of arteries due to a build up of deposits on the inner arterial wall. And atherosclerosis is one of the main causes of heart attacks and strokes."
The large-scale study was able to demonstrate that patients with elevated levels of triglycerides in their blood had a significantly higher mortality rate than comparison groups with a similar health history. Blood triglyceride levels rise substantially in people who eat a high-fat diet. As a result of biochemical changes, the triglycerides develop toxic properties that activate the body's innate immune system via the NLRP3 inflammasome. This initiates a series of self-destructive processes including those in which the walls of the arteries are attacked and the blood vessels become occluded, reducing blood flow.