To understand how too much dietary sugar can impact your cholesterol levels, you first need to understand how sugar creates triglycerides. When you eat fructose, your body sends it to the liver, which converts the fructose molecules into triglycerides (basically fat). The liver exports the triglycerides into the bloodstream, where they’re picked up and stored as body fat.
The transport system that moves triglycerides from the liver into the bloodstream can only work so fast, so if too much fructose enters the liver at once, the triglycerides accumulate inside the liver, leading to a condition called (unsurprisingly) fatty liver.
The body makes very low-density lipoprotein (VLDL) to transport these extra triglycerides. As the VLDL circulates in the blood, triglycerides are deposited and the particle gets smaller, eventually becoming a low-density lipoprotein (LDL), the “bad” cholesterol. The more sugar you eat, the more harmful LDL you’re left with.
High insulin levels (from high carbohydrate intake) also raise cholesterol production in the body by stimulating the cholesterol-producing enzyme HMG-CoA reductase.
High sugar consumption lowers high-density lipoprotein (HDL), the “good” cholesterol that acts as a vacuum cleaner and removes cholesterol from the arterial walls. Low HDL is one of the hallmarks of metabolic syndrome. The more sugar you eat, the lower your good HDL and the higher your bad LDL and triglycerides.
Refined sugar contains no fiber, but vegetables, whole grains, and fruits do! Dietary fiber sweeps cholesterol out of the body before it can be absorbed, keeping your arteries clear of buildup that would otherwise turn into dangerous plaque on the arterial walls. Try to eat at least 30 grams of dietary fiber each day.