HDL plays an important role in transporting cholesterol from the peripheral tissues to the liver, where it can be excreted; this process is known as reverse cholesterol transport (RCT). (The liver is the main organ for excretion of cholesterol, doing so either directly or by converting cholesterol into bile acids.) It is important to remember that most HDL measured in the blood is derived from the liver and intestine. Therefore, the concentration of HDL in plasma does not reflect cholesterol efflux from blood vessels or the efficiency of RCT. Moreover, HDL function in RCT is not mirrored by HDL measurements. 
People on high-carb diets full of pasta, bread and sugar-even those who exercise frequently-tend to have lower HDL levels than those who eat plenty of protein and good fats along with veggies and whole grains. “Low HDL often results when people are told to get all the fat out of their diets and eat carbohydrates instead,” Willett says. A British study showed that people with high HDL levels tend to focus on slower-burning carbs, such as beans and fruit.
Trans fatty acids are likely present in many of your favorite prepared foods— anything in which the nutrition label reads "partially hydrogenated vegetable oils" — so eliminating them from the diet is not a trivial task. But trans fatty acids not only increase LDL cholesterol levels, but they also reduce HDL cholesterol levels. Removing them from your diet will almost certainly result in a measurable increase in HDL levels.
Other supplements that have been suggested for cholesterol have less evidence of being useful. In the case of red yeast rice, there is a potential danger because it contains a naturally-occurring form of lovastatin, a prescription drug. Garlic has now been shown to be ineffective for lowering cholesterol. Other supplements and food you may see touted include policosanol, coenzyme Q10, green tea, and soy.
Barley contains a powerful type of soluble fiber that helps keep cholesterol levels in check by effectively lowering total and LDL cholesterol without affecting HDL. This beta-glucan fiber works by preventing the body's absorption of cholesterol from food. Look for minimally processed pearled barley, the variety most commonly found in supermarkets.
So far, these studies have been disappointing, to say the least. The first major trial (concluded in 2006) with the first CETP inhibitor drug, torcetrapib (from Pfizer), not only failed to show a reduction in risk when HDL was increased but actually showed an increase in cardiovascular risk. Another study with another CETP inhibitor - dalcetrapib (from Roche) - was halted in May 2012 for lack of effectiveness. Both of these related drugs significantly increased HDL levels, but doing so did not result in any clinical benefit.
Flavor foods with herbs and spices whenever you can. It’ll help you cut back on condiments high in saturated fat while maximizing flavor. Spices and herbs also pack antioxidants, which can help improve cholesterol levels when combined with veggies. Ones we love: Basil, cilantro, rosemary, sage, ginger, garlic, tarragon, black and red chili pepper, mint, and oregano.