Avocados are high in monounsaturated fatty acids, which provide many health benefits such as decreasing LDL and raising HDL in those suffering from hypercholeseterolemia. LDL is the cholesterol that can clog your arteries, while HDL cholesterol acts to prevent this from happening. A study in the "Archives of Medical Research" discovered that after only seven days on an avocado-enriched diet, hypercholeseterolemic patients showed a decrease in total cholesterol of 17 percent, a decrease in LDL cholesterol of 22 percent and an increase in HDL cholesterol of 11 percent.