LDL cholesterol is affected by diet. Knowing which fats raise LDL cholesterol and which ones don't is the first step in lowering your risk of heart disease. In addition to the LDL produced naturally by your body, saturated fat, trans-fatty acids and dietary cholesterol can also raise blood cholesterol. Monounsaturated fats and polyunsaturated fats appear to not raise LDL cholesterol; some studies suggest they might even help lower LDL cholesterol slightly when eaten as part of a low-saturated and trans-fat diet.