When most people think of cholesterol, they think of the bad stuff. But there are actually two types of cholesterol, the “bad” and the “good” kind.
Cholesterol is a naturally occurring fatty substance in our blood that is formed in our livers or digested from the foods we eat. It helps form the structure of every cell in our bodies, and it also aids in tissue and hormone formation, protects nerves, and helps with digestion.
But, as you know, it’s not all good. Low-density lipoprotein, or LDL cholesterol, is considered bad. High LDL cholesterol is what puts people at greater risk for cardiovascular disease, as the excess sticks to the walls of your arteries forming plaque, which can cause those arteries to harden and narrow (a condition known as atherosclerosis). If a blood clot forms and blocks an artery, you could suffer from a heart attack or stroke.
High-density lipoprotein, or HDL cholesterol, on the other hand, is the good stuff. Its job is to cleanse the bloodstream by carrying bad cholesterol back to the liver. What’s important is that you maintain the proper ratio between the two, and by lowering LDL and raising HDL cholesterol, you can reduce your risk of cardiovascular disease.
When dealing with the cholesterol dilemma, many people focus on ways to lower their bad cholesterol. There are popular drugs known as statins that do this, as well as plenty of natural routes you can take. A healthy diet and regular physical exercise can go a long way in naturally lowering your LDL cholesterol.
But that’s only half of the equation. What about raising your good cholesterol level?
Past research has linked certain lifestyle factors to high-density lipoprotein cholesterol (HDL-C), but a new study in the American Heart Journal was the first to examine the association between changes in lifestyle factors and long-term changes in HDL-C.
The 14-year study focused on 4,168 U.S. male physicians, followed up between 1982 and 1997, with HDL-C measured at the beginning and end points.
Specifically, researchers looked at changes in alcohol consumption, physical activity, body mass index (BMI) and smoking, which have all been associated with HDL-C.
Body Mass Index
BMI is a measure of body fat based on height and weight. A BMI below 25 is considered healthy, while 25-29.9 is considered overweight, and a measure above 30 is considered obese.
In this study, the subjects were divided into four groups. Those who:
- Maintained a BMI of ≥25 throughout the study (reference)
- Increased from <25 to ≥25 during the study
- Decreased from ≥25 to <25 during the study
- Maintained a BMI of <25 during the study
For alcohol consumption, moderate intake was considered one or more drinks per day, while less than one drink a day was deemed to be less than moderate intake. Here the groups were those who:
- Consumed <1 drink per day throughout the study (reference)
- Increased consumption from <1 to ≥1 drink per day during the study
- Decreased consumption from ≥1 to <1 drink per day during the study
- Maintained an alcohol consumption of ≥1 drink per day
Subjects were categorized as:
- Smoking throughout the study (reference)
- Quitting smoking
- Initiating smoking
- Never smoking
Finally, regular physical activity was defined as exercising to the point of sweating at least once per week, and participants fell into the following categories:
- Exercising to sweat >1 time per week (reference)
- Increasing exercise from <1 to ≥1 time per week
- Decreasing exercise from ≥1 to <1 time per week
- Exercising ≥1 time per week throughout the study
So what did researchers find? Here are the highlights:
Stable BMI of less than 25 (healthy weight) or BMI reduction from greater than 25 (overweight) to below 25 were associated with increases in HDL-C over 14 years.
Having one or more drinks per day (moderate intake) or an increase in alcohol consumption from less than one drink a day to one or more drinks per day was also associated with increases in HDL-C of over the course of the study.
Furthermore, men who had been active at the beginning of the study but became sedentary saw significant reductions in their HDL-C.
The study authors focused less on the smoking aspect, as very few subjects smoked at baseline or follow-up (5.9% and 2.4%, respectively).
Researchers concluded: “In a cohort of male physicians with measurements of HDL-C 14 years apart, the authors found that stable low BMI, decreasing BMI, moderate alcohol consumption, and increasing alcohol consumption were all associated with increases in HDL-C, whereas decreases in physical activity were associated with decreases in HDL-C.”
Making Positive Lifelong Changes
So it would seem that one can significantly improve their good cholesterol by making positive lifestyle choices. Nothing too shocking there (well, maybe the fact that it could be in your best interest to relax with a drink every day). But it is encouraging to see that making healthy decisions over the long term really can impact your health down the road.
Our advice: Begin making positive changes immediately, and try to stick with them. You’ll be thankful you did one day.
 Rahilly-Tierney C., Sesso H.D., Djoussé L. and Gaziano J.M. Lifestyle changes and 14-year change in high-density lipoprotein cholesterol in a cohort of male physicians. Am Heart J 2011;161:712-8.