High triglyceride and LDL cholesterol levels increase the risk of strokes and heart attacks. Researchers recently investigated whether substituting saturated fats with omega 6 can help to reduce the bad cholesterol levels that are associated with diabetes.
Cholesterol is a substance found in cells and in the bloodstream. It plays a vital role in the production of cell membranes, bile acids that help digest fatty foods, and hormones. Cholesterol is also important for proper neurological functioning. Our bodies manufacture cholesterol, but we also get it from foods that we eat such as fatty meats, cheese, and egg yolks.
A person’s total cholesterol count represents the total amount of cholesterol in their blood. A total cholesterol count measures high-density lipoproteins (HDL), low-density lipoproteins (LDL), and triglycerides. HDL absorbs cholesterol and carries it to the liver so that it can be excreted from the body, LDL carries cholesterol to all the cells in the body, and triglycerides, which the body uses for energy.
Elevated levels of triglycerides and LDL cholesterol are considered markers of poor health since they can build up as plaque deposits on the blood vessel walls reducing blood flow and leading to high blood pressure and an increased risk for strokes or heart disease. Since diabetes and insulin resistance tend to lower HDL and elevate LDL cholesterol levels, these conditions are also associated with increased risk for strokes or heart disease. When individuals are insulin resistant or diabetic and have a poor lipid profile, they are said to have diabetic dyslipidemia.
Saturated vs. Unsaturated Fats
Not all dietary fats are alike. Saturated fats are found in meats, dairy products such as cheese and butter, and some plants such as coconuts and palm kernels. Saturated fats tend to be solid at room temperature and have been shown to raise levels of both total blood cholesterol and LDL cholesterol. Unsaturated fats are found in fish, avocados, nuts, and seeds. Unlike saturated fats, unsaturated fats are liquid at room temperature and have been shown to raise HDL and decrease LDL cholesterol levels.
In a recent study published in The American Journal of Clinical Nutrition, researchers in Quebec, Canada conducted a randomized controlled trial to investigate whether substituting dietary saturated fatty acids with omega-6 unsaturated fatty acids reduced diabetic dyslipidemia in men. Thirty-six men with diabetic dyslipidemia agreed to eat a controlled diet for a period of eight weeks. For the first four weeks, all of the participants followed the same diet designed to “wash out” their systems. For the following four weeks, they ate diets with equal amounts of fat but half of the participants ate omega-6 unsaturated fats and half ate saturated fats. Thirty men completed the study.
Omega 6 Instead of Saturated Fats Decreased Bad Cholesterol
The researchers found that substituting saturated fats for unsaturated ones led to a significant decrease in LDL cholesterol levels. The substitution also regulated the intestinal expression of several key genes involved in lipoprotein metabolism. As such, they concluded that the unsaturated fats reduced the LDL particle number by decreasing the production of these lipoproteins. To their knowledge, this study is the first to evaluate the impact of the substitution of omega-6 unsaturated fats for saturated fats on cholesterol using tracer analyses in individuals with diabetic dyslipidemia.
Written by Debra A. Kellen, PhD
(1) Drouin-Chartier, J. P., Tremblay, A. J., Lépine, M. C., Lemelin, V., Lamarche, B., & Couture, P. (2018). Substitution of dietary ω-6 polyunsaturated fatty acids for saturated fatty acids decreases LDL apolipoprotein B-100 production rate in men with dyslipidemia associated with insulin resistance: a randomized controlled trial. The American Journal of Clinical Nutrition, 107(1), 26-34. doi: 10.1093/ajcn/nqx013.