Triglycerides Play a Bigger Role in Heart Disease than Previously Thought
If you’re an adult, chances are your doctor has ordered a blood lipid panel during a routine physical. Doctors follow well-established guidelines to monitor the different types of fats (lipids) circulating in your bloodstream. That’s because scientists identified cholesterol levels as an independent risk factor for cardiovascular disease decades ago. Of course, we all know by now that high levels of “bad” LDL-cholesterol are bad news. You may even know that it’s helpful to have high levels of “good” HDL-cholesterol. These two forms of cholesterol have been linked to the risk of developing atherosclerosis; the disease that can clog blood vessels and lead to heart attack and stroke. But what about the third number on your lipid report?
Triglycerides are fatty acids circulating in the blood. Like cholesterol, they’re transported by special proteins. Epidemiological studies suggest that higher triglyceride levels are linked to a greater risk of coronary artery disease (the precursor to heart attack). These types of studies look at possible relationships between different events. Among people who suffer heart attack, for example, “trigs” tend to be high, so we can infer the two are related. But we can’t be sure high trigs CAUSE heart disease.
Now scientists at the University of Michigan have conducted a massive survey of genes that code for proteins involved in lipid transportation. Using information from more than 180,000 people around the world, they identified in excess of 150 changes in human DNA that influence blood lipid levels. These “genetic variants” were then linked to the risks of diseases such as heart disease, high blood pressure and diabetes.
Among other important findings, the researchers discovered that triglycerides play a bigger role in heart disease than previously thought. Here’s the kicker: Diets high in refined carbohydrates (think sugar and starch) often result in high blood triglyceride levels, especially among people with insulin resistance and/or obesity. You can lower your triglyceride levels through exercise and better diet (including more fatty fish, for example) and by eating fewer simple carbs.
Do R, Willer CJ, Schmidt EM, Sengupta S, Gao C, Peloso GM, et al. Common variants associated with plasma triglycerides and risk for coronary artery disease. Nat Genet. 2013 Oct 6. doi: 10.1038/ng.2795. [Epub ahead of print]