What effect do high-fiber diets have on cholesterol levels?

High-fiber diets are recognized for their beneficial effects on cholesterol levels, particularly total and low-density lipoprotein (LDL) cholesterol levels. The mechanism behind this involves soluble fiber, which can bind to bile acids in the intestine. This binding promotes the excretion of bile acids, prompting the liver to use circulating cholesterol to produce more bile acids, ultimately reducing the amount of cholesterol in the bloodstream.

Numerous studies support the idea that a diet rich in fiber, especially soluble fiber from sources such as oats, beans, and psyllium, leads to a reduction in LDL cholesterol. This reduction is significant because high levels of LDL cholesterol are associated with an increased risk of cardiovascular diseases.

High-fiber diets may also contribute to an overall improvement in heart health by promoting better lipid profiles and reducing the risk of heart disease. Therefore, the correct answer highlights the positive impact of high-fiber diets on cholesterol levels, particularly in lowering both total and LDL cholesterol.