Millions of Americans enjoy an alcoholic beverage here and there, which some research has concluded can even be healthy. But heavy drinking can take a real toll on the body; it has been linked to heart problems and risk factors for diabetes.
A recent study looked at the link between alcohol consumption and risk of metabolic syndrome — a group of co-occurring conditions that increase the risk for heart disease, stroke and diabetes.
The researchers found that compared to not drinking, heavy drinking was linked to an increased risk of metabolic syndrome, and very light drinking was associated with a decreased risk of metabolic syndrome.
The researchers concluded that further research is needed to see if abstinence from alcohol could help prevent the development of metabolic syndrome.
This study was conducted by Li Yan from the Department of Endocrinology of Sun Yat-sen Memorial Hospital at Sun Yat-sen University in Guangzhou, China, and colleagues.
The researchers analyzed six previously published studies about the effects of alcohol consumption on the risk of metabolic syndrome.
The six studies had a total of 28,862 participants with 3,305 cases of metabolic syndrome. Two of the studies were conducted in Africa, two in Europe and two in America.
Four of the studies included both men and women, and two studies only included men. The participants' ages ranged from 18 to 100. The follow-up periods ranged from three to 13.6 years.
The researchers converted reported daily alcohol consumption to grams per day and categorized all the participants from the previous studies into six groups:
- Nondrinker: 0 grams per day
- Very light drinker: 0.1 to 5 grams per day
- Light drinker: 5.1 to 10 grams per day
- Moderate drinker: 10.1 to 20 grams per day
- Moderate-heavy drinker: 20.1 to 35 grams per day
- Heavy drinker: More than 35 grams per day
A standard drink is any drink that contains about 14 grams of alcohol.
The risk associated with each level of drinking was reported in comparison to nondrinkers.
The researchers found that very light drinkers had a 14 percent decreased risk of developing metabolic syndrome compared to the nondrinkers. The heavy drinkers were found to have an 84 percent increased risk of metabolic syndrome compared to the nondrinkers.
The calculated risks associated with the other categories of drinking were not significant, the researchers found.
The overall risk for metabolic syndrome associated with drinking compared to not drinking was a 10 percent increased risk.
"It's been known that light drinkers tend to have improved cardiovascular health, while heavy drinkers have worse cardiovascular health," said Jeffrey Schussler, MD, an interventional cardiologist on the medical staff at Baylor Heart and Vascular Hospital and Baylor University Medical Center in Dallas, Texas.
"This study suggests that one of the reasons is an association between increased alcohol consumption and metabolic syndrome, which is a condition associated with diabetes, hypertension, and heart disease. I generally recommend to my patients that if they want to drink alcohol, it's fine for their heart, but not to excess," said Dr. Schussler, who was not involved in this study.
The authors of this study suggested that future research would be more conclusive if researchers were to look at the effects of alcohol consumption on the individual factors of metabolic syndrome, such as high blood pressure, high blood sugar level, large amount of excess fat around the waist and high cholesterol.
The researchers also suggested that future studies should consider the specific amount and type of alcohol.
The authors noted a few limitations of their study.
First, there is no standard measurement of alcohol consumption, so the interpretation of study findings may have been biased.
Second, all the data on level of alcohol consumption was self-reported by the study participants who may have lied about their daily use.
Third, the participant groups were found to be very diverse and different from each other when separated by geographical location. Therefore, the researchers wrote that future studies should consider characteristics, such as race, that were not considered in the reviewed studies.
Lastly, the current analysis did not differentiate between beer, wine and liquor because only two studies included information on types of alcohol.
This analysis was published online on October 16 in Clinical Nutrition.
The National Natural Science Foundation of China and the Research Fund for the Doctoral Program and for the New Teacher Program of the Higher Education of China provided funding.