High-density lipoprotein or HDL, nicknamed the "good" cholesterol, protects the body from the accumulation of fats. HDL captures low-density lipoprotein or LDL and triglycerides, transporting them to the liver to be stored or excreted.
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The healthy range of HDL is 40mg/dL to 65mg/dL for men and 50mg/dL to 65 mg/dL for women--but the HDL level is not as important as the HDL to LDL ratio, which is ideal at 0.4.
Low HDL, or hypoalphalipoproteinemia, is also known as HA.
In 40 percent to 60 percent of Mexican American and Native American people in the U.S., a genetic variant called ABCA1 has been linked to HA by researchers from Mexico City. Obesity, diabetes, diets high in carbohydrates and low in omega-3 fats and smoking can each cause HA. People who take anabolic steroids or progestins are also at risk.
Raising the HDL is accomplished by a few people by simply changing the diet--eliminating simple carbohydrates such as sugar, white flour and white rice while adding omega-3 fats such as avocado, salmon, walnuts and olive oil. But the only food proven to raise HDL significantly is alcohol. Researchers in England reported that consuming 1 oz. alcohol per day increases HDL cholesterol levels by 4 mg/dL. There is a limit to alcohol's beneficial effect. One to two servings of 4 oz. red wine each day is the maximum amount recommended.
Weight loss can raise HDL at a rate of 1mg/dL for every seven lbs. weight loss. That means a woman who loses just 14 lbs. may see her HDL go from an unhealthy 49 to an acceptable level of 51mg/dL even if she is still obese at her new weight. Smoking cessation and 30 minutes of vigorous activity a day also can raise HDL significantly.
Until recently, high HDL levels were considered universally beneficial: The higher, the better. Now physicians understand that an HDL above 65, called hyperalphalipoproteinemia or HA, is too much of a good thing. Especially when HDL is greater than 90mg/dL, the risk of arteriosclerosis rises. This is because at a very high level, HDL reverses its job and starts moving fat from the liver to body tissues.
The groups at highest risk of HA are black Americans and Japanese-American men, long-distance runners and very high alcohol consumers. Dilantin and estrogen prescribed without progesterone can all cause HA as well. People taking niacin, statins and fibrates to raise their HDL should make sure levels they achieve don't rise above 65mg/dL.
Treating HA is not accomplished with medication. It requires reducing all modifiable risks.
The HDL/LDL Ratio
HDL is not considered in a vacuum. The Centers for Disease Control and Prevention recommends a target HDL/LDL ratio of 0.4 as one of several health goals.
When LDL and triglyceride levels are too high, these factors take precedence. But especially for diabetics and those with high blood pressure, correcting the entire lipid profile is a high priority.
A physician in this circumstance may focus on lowering LDL and triglyceride levels and correcting blood sugar levels, to the exclusion of all else, By understanding the importance of HDL as the body's way of helping to eliminate LDL and triglycerides, patients can take charge of correcting their HDL levels to the greatest possible extent. Simple steps such as correcting diet, enjoying 4 oz. red wine each day, exercising 30 minutes each day and eliminating cigarettes can make a significant impact on HDL.
Abnormal HDL in Children
American children are exhibiting unprecedented rates of obesity, Type 2 diabetes, high LDL and low HDL.The Standard American Diet, along with decreased physical activity demands, are commonly thought to be responsible. Because the liver--a critical and easily damaged organ--is affected by abnormal HLA, obtaining and maintaining normal HDL levels throughout childhood is essential. The good news is that the same steps that prevent obesity and high blood sugars also work toward a healthy HDL. Serving children a diet low in simple carbohydrates that incorporates daily servings of omega-3 fats is a good place to start.
Abnormal HDL Worldwide
Whereas the North American and European diets changed from high protein and low carbohydrates over 150 to 200 years, people in developing nations are seeing those changes in one generation. This, together with exploding rates of diabetes and obesity across the globe--especially in children and adolescents--is expected to result in an earlier onset of cardiovascular disease and arteriosclerosis.
To allow HDL to protect our arteries and veins, human beings must eat as they have eaten in the past: fish, vegetables and the berries and nuts our ancestors spent their days gathering. And we need to move throughout the day as we did before cars, planes and texting. Otherwise, the gains in human longevity--achieved by conquering infectious diseases, making childbirth safer and our ability to effect cures in many cancers and other serious illnesses--will be lost and 21st century children will not live as long as their grandparents.