How to raise the HDL Bar

We often refer to high cholesterol levels to be bad for health especially the low-density lipoprotein cholesterol (LDL) component.  High density Lipoprotein (HDL) Cholesterol however is often referred to as good cholesterol.  Lipoproteins are complex particles composed of multiple proteins which transport all the fat molecules (Lipids) around the body within the water outside cells. HDL particles enlarge while circulating in the blood, aggregating more fat molecules and transporting up to hundreds of fat molecules per particle. It facilitates reverse cholesterol transport and is vasculo-protective in nature.

The normal HDL c levels in men are more than 40 mgs/dl and more than 50 mgs/dl in women. A number of population-based studies have shown that communities with levels of HDL cholesterol more than 60 mgs/dl have significant protection against vascular events like heart attacks, strokes and blockages in limb vessels.

Benefits of HDL Cholesterol:

It removes excess cholesterol from the bloodstream and transports it to liver for excretion through bile. It protects against heart disease by maintaining the arteries supplying blood to the heart healthy and by reducing inflammation in their walls thus minimizing the chance of a blockade leading to a vascular event.

Factors That Affect HDL Cholesterol Levels:

A family history with genetic propensity, a diet high in saturated fats and trans fats can lower HDL c. Other factors can be lack of exercise, cigarette smoking and overweight / obesity.

Effective Methods to Increase HDL Cholesterol:

Diet: A diet rich in fruits, vegetables, salads, high fiber containing diet, whole grains and legumes. Aim at having 25 to 30 grams of fiber per day.

Consuming more unsaturated fats like nuts, olive oil and Items rich in Omega 3 Fatty Acids: Walnuts, flax seeds, fatty fish and limiting butter, coconut oil and partially hydrogenated oils like Vanaspati etc. help.

Improve Life Style:

Regular aerobic exercise of moderate intensity for at least 150 minutes per week. Brisk walks and at least 8,000 steps per day. Limiting sedentary habits like watching TV and playing video games to less than 2 hours a day are useful.

Getting enough sleep of 7 to 8 hours per night. Engaging in stress reducing activities, like meditation, yoga, deep breathing exercises are desirable.

Maintaining a healthy weight with a body mass index less than 25 and quitting smoking and drinking alcoholic beverages should be practiced.

What About drugs?

This has been an area of intense research which has been rather frustrating.

Niacin (Nicotinamide): This compound is also available as a over the counter medicine. In high doses it does increase HDL c by up to 30% along with a reduction in triglycerides which is an accompaniment in most cases. It can produce very unpleasant flushing as a side effect. Although small studies showed a benefit in the outcomes of events when combined with LDL c lowering agents like statins but this was not accomplished in studies with sufficient power.

Fibrates: Drugs like fenofibrate and gemfibrozil can increase it up to 15-20%. The story of fibrates seems to have had a serious setback when Pemafibrate a much more effective fibrate despite reducing triglycerides by 26% and increasing HDL c by 5% did not have any favorable effect on the outcomes.

Omega 3 Fatty Acids

These agents traditionally have been considered to be safe modality to reduce triglycerides and increase HDL c. This concept was suddenly hyped by a recent study showing a significant benefit in the patients consuming a very high dose of synthetic omega 3 fatty acids with statins. This led to a short-lasting boom in its use. It was however soon realized that the study had a serious flaw because the compound was being compared with a mineral oil which increased the bad cholesterol (LDL C). This finding was not duplicated in a study following it where omega 3 fatty acid with statins were compared with corn oil and statins. Thus, the study has punctured the enthusiasm of using omega 3 fatty acids as a favorable agent.

Cholesterol ester transfer proteins (CETP) inhibitors: These drugs were designed to specifically increase HDL c. However, the first drug from this group torcetrapib proved to be dangerous because despite producing a substantial increase in HDL c it increased vascular mortality because of increasing other risk factors like blood pressure significantly.

Other CETP inhibitors like anacetrapib which seemed to be reducing heart attacks modestly but had a lack of effect on ischaemic stroke, and there was also evidence that it accumulates in fatty tissues with prolonged dosing, which could raise safety concerns. Merck the company developing it abandoned the program when they realized its futility. Likewise other pharma companies did not find future in these agents. As of today, the experience with this group of drugs has been very disappointing.

Take Home Message:

HDL c an important lipoprotein is a good predictor of vascular events like heart attacks and strokes etc. It has a genetic propensity and South Asians in general have lower levels than Caucasians and Orientals. Good life style, heart healthy diet, regular exercise and keeping body weight in check are the best and effective measures to modestly increase the levels by around 10 to 15%. Potent drugs to increase it have not worked so far and can be deleterious. The best way in high-risk individuals is to keep the bad cholesterol (LDL c) to very low levels. We have safe drugs like statins to achieve it and nullify the effect of low HDL C.

Author is Founder Director Gauri Kaul Foundation