THE BLOG
06/03/2011 08:33 am ET | Updated Nov 15, 2011

Cholesterol: The Good, the Bad and the Truth

A recent large government study found that raising levels of HDL "good" cholesterol using a drug did not reduce the risk of heart disease.

As The New York Times reported:

Patients taking the medicine along with Zocor had higher levels of H.D.L. and lower levels of triglycerides, a fat in the blood. Despite these seeming improvements, the patients fared no better and may have done slightly worse than those taking Zocor alone. That is why the entire theory behind trying to increase H.D.L. levels in patients with heart disease may need rethinking.

Why?

Many people, including most physicians, believe that HDL is "good cholesterol" and LDL is "bad cholesterol." Therefore, anything that raises HDL cholesterol is good.


It's not so simple. Not everything that raises HDL is good, and not everything that lowers it is bad.

Think of HDL like the garbage trucks of your body. Your body makes HDL to remove excessive cholesterol from your blood and tissues, a process known as "reverse cholesterol transport." HDL transports cholesterol back to your liver where it is metabolized and removed from your body.


Most Americans eat a diet that's relatively high in saturated fat, animal protein, and cholesterol--i.e., a lot of "garbage." Those people who have a lot of garbage trucks--in other words, who have high HDL levels--are more efficient at getting rid of extra fat and cholesterol in their diet.


Your body's ability to make more garbage trucks (raise your HDL) is, in part, genetically determined. Some people can make more garbage trucks than others. As a result, they have a lower risk of a heart attack or stroke than those who eat a high-fat, high-cholesterol diet who have lower HDL levels.


However, the relationship of HDL to risk of heart disease and stroke assumes that people are not changing their diet or drugs. This relationship was first noticed in Framingham, a town outside of Boston in which most people ate a high-fat, high-cholesterol diet. Those people who had higher HDL levels had lower rates of heart disease than those with lower HDL levels. More garbage trucks, less garbage left behind.


But things get very different when you try to raise HDL levels, whether by diet or by drugs.

Not everything that raises HDL is good for you. For example, if you increase the amount of saturated fat and cholesterol in your diet, you may increase your HDL because your body is trying to get rid of the extra "garbage" (fat and cholesterol) by increasing the number of available garbage trucks (HDL) if you are genetically able to do so. Eating a stick of butter or having a cheeseburger will raise HDL in those who are able to do so, but that does not mean that butter and burgers are good for your heart. They aren't.


This is a source of confusion in studies of the Atkins diet, in which HDL increases along with LDL, so the net cardiovascular effect is considered a wash. However, a report in The New England Journal of Medicine made it clear that it's important to look at arteries, not just risk factors. It reported that in animal studies, in which the arteries can be directly viewed, an Atkins-type diet increased coronary atherosclerosis (blockages) mediated via mechanisms that are not related to traditional risk factors such as HDL and LDL. Arteries were clogged on the high-fat, high-protein, low carbohydrate diet but clean on the low-fat, moderate-protein, high-carbohydrate diet.

Niacin will raise your HDL, and so will another drug, torcetrapib. Last week, government scientists announced that niacin not only did not provide any protection against heart attacks when taken with a statin drug in patients with heart disease but also slightly increased their risk of stroke. Five years ago, researchers found that torcetrapib actually increased the risk of a heart attack, so they had to stop the study and take the drug off the market.


Both drugs raise HDL by interfering with reverse cholesterol transport, causing HDL to build up. It's like having a traffic jam of garbage trucks--more trucks, but they don't work as well.


Not everything that lowers HDL is bad for you. If you change from a high-fat, high-cholesterol diet to a healthy low‑fat, low-cholesterol diet, your HDL levels may stay the same or even decrease temporarily because there is less need for it. When you have less garbage, you need fewer garbage trucks to remove it, so your body may make less HDL. Thus, a reduction in HDL on a whole foods, low-fat plant-based diet is not harmful.


We know this is true because instead of just measuring risk factors like HDL, we measured what actually happens to the progression of coronary heart disease in people who went on diets that were very low in "garbage"--i.e., very low in cholesterol, saturated fat, total fat, and refined carbohydrates and high in fruits, vegetables, whole grains, legumes, and soy products.


Their HDL levels came down by 9 percent after one year, but their LDL ("bad") cholesterol levels came down even more, by an average of 40 percent. None of these patients was taking cholesterol-lowering drugs.


Even though their HDL levels decreased, these patients showed reversal of their heart disease using state-of-the-art measures such as quantitative coronary arteriography, cardiac PET scans, thallium scans, and radionuclide ventriculography in randomized controlled trials published in leading peer-reviewed journals. On average, they showed even more reversal of their heart disease after five years than after one year. Also, there were 2.5 times fewer cardiac events such as heart attacks, bypass surgery, and angioplasty in these patients.


A low HDL in the context of a healthy low-fat diet has a very different prognostic significance than a low HDL in someone eating a high-fat, high-cholesterol diet. People living in countries such as Asia that consume a low-fat diet have low HDL levels yet among the lowest rates of heart disease in the world.


So, rather than being concerned about how to raise your HDL, eat a whole foods, plant-based diet--and spend a few minutes a day exercising, meditating, and loving more. Heart disease is completely preventable--today--in at least 95 percent of people simply by changing our diet and lifestyle, and with medications when indicated. We don't need a new drug or breakthrough technology; we simply need to put into practice what we already know.

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