New research offers further support for the possible heart health benefits of moderate drinking, after finding consuming up to two alcoholic beverages daily may slow the decline of "good" high-density lipoprotein cholesterol.
The research team - from Pennsylvania State University and Kailuan Hospital in China - recently presented their findings at the American Heart Association's Scientific Sessions 2016 in New Orleans, LA.
There are two types of cholesterol: low-density lipoprotein (LDL) and high-density lipoprotein (HDL).
Referred to as the "bad" cholesterol, LDL cholesterol can cause a buildup of plaque in the arteries at high levels - a condition known as atherosclerosis. This can increase the risk of heart attack and stroke.
HDL cholesterol helps remove LDL cholesterol from the arteries, carrying it back to liver, where it is broken down and removed from the body. This process can reduce the risk of heart attack and stroke, earning HDL the title of "good" cholesterol.
According to the Mayo Clinic, optimal levels of HDL for both men and women are 1.6 millimoles per liter or above. Levels below 1.3 millimoles per liter for women or 1 millimole per liter for men may raise the risk of high LDL cholesterol, and subsequently, greater risk of heart attack and stroke.
Lifestyle interventions, such as adopting a healthy diet, engaging in physical activity, and quitting smoking, have been shown to increase HDL levels. Now, new research suggests moderate alcohol intake might also benefit HDL levels.
Slowest reduction in LDL for moderate drinkers
Study co-author Shue Huang, of Pennsylvania State University, and team analyzed the data of 80,081 Chinese adults who were an average age of 49 years.
Participants' alcohol intake was assessed at study baseline in 2006, and based on this, they were allocated to one of five groups: never, past, light, moderate, and heavy drinkers.
Moderate drinking was defined as 0.5-1 drink a day for women and one to two drinks daily for men. The researchers also looked at what types of alcohol the participants consumed.
Subjects' HDL levels were also measured at study baseline in 2006 and again in 2008, 2010, and 2012.
All adults were free of cardiovascular disease and cancer, and they did not use any LDL-cholesterol lowering medications during follow-up.
The HDL levels of all participants decreased during follow-up. However, the researchers found moderate drinkers experienced a slower decline in HDL, compared with never-drinkers and heavy drinkers (defined as at least one drink a day for women and more than two drinks daily for men).
The reduction in HDL levels for moderate drinkers was 0.017 millimoles slower annually, while HDL levels for never-drinkers and heavy drinkers were 0.012 and 0.008 millimoles slower, respectively.
Beer, hard liquor associated with slower decline in LDL cholesterol
Further analysis revealed that slower decline in HDL cholesterol was dependent on the type of alcohol consumed.
The researchers found HDL levels fell more slowly with moderate beer intake, while among subjects who consumed hard liquor, only light and moderate drinkers saw slower HDL decline.
The authors note there was an insufficient number of wine drinkers to determine whether the beverage was associated with slower reduction of good cholesterol.
The team says further research is needed to determine whether moderate alcohol intake is beneficial for HDL cholesterol among other populations, and to determine whether the slower HDL reduction with alcohol consumption is associated with clinically relevant outcomes.
In conclusion to their study, the authors write:
"Alcohol consumption was associated with slower HDL decreases, with moderate consumption slowest. However, the data suggested differential effects on the basis of alcoholic beverage type."