- Moderate alcohol consumption is believed to have protective cardiovascular health benefits, possibly through its effects on hormones.
- Researchers examine alcohol's effect on three hormones: dehydroepiandrosterone sulfate (DHEAS), testosterone and estradiol.
- Moderate alcohol consumption appears to increase plasma DHEAS levels for both men and women.
Moderate alcohol consumption is known to have positive, possibly even protective, cardiovascular health effects. A study in the May issue of Alcoholism: Clinical & Experimental Research investigates the role that certain hormones may play in the cardiovascular benefits of alcohol, specifically, dehydroepiandrosterone sulfate (DHEAS), testosterone and estradiol. Researchers found that moderate alcohol consumption can increase plasma DHEAS levels for both men and women, decrease plasma testosterone among men, and has no effect on plasma estradiol levels.
"DHEAS is believed to play a protective role against atherosclerosis in both genders," said Henk F.J. Hendriks, a senior scientist at TNO Nutrition and Food Research in The Netherlands and corresponding author for the study, "just like low testosterone does for men." Atherosclerosis is characterized by irregularly distributed lipid deposits in the arteries, which can provoke fibrosis and calcification, impede blood flow, and/or eventually shut off blood flow. "This is the first diet-controlled intervention study which shows that moderate alcohol drinking can increase DHEAS," he added.
"Estradiol, or estrogens in general," Hendriks continued, "may be pivotal in the protection from coronary heart disease in premenopausal women. An association between moderate alcohol consumption and breast cancer has been proposed, which may be mediated through an increase in estradiol."
"A lot of the earlier work in this area looked at hormones because of associations that had been found between alcohol and breast cancer," said Eric B. Rimm, associate professor of epidemiology and nutrition at the Harvard School of Public Health. "We also know that the rates of coronary heart disease among women tend to go up five to ten years after that of men, which seems to be related to postmenopausal factors. So, this study's examination of the impact that alcohol may have on hormones is a logical outgrowth of the phenomenon that women tend to get heart disease later in life than men."
For this experiment, 10 middle-aged men and nine postmenopausal women - all considered healthy, non-smoking, and moderate drinkers - consumed either regular beer or nonalcoholic beer with dinner during two successive periods of three weeks. During the period of beer consumption, the men consumed 40 and the women 30 grams per day. The composition of the participants' diet was the same during all six weeks. At the end of the six-week study, fasting blood samples were collected in the morning.
The results indicate that moderate alcohol consumption can have an impact on circulating hormone levels. Plasma DHEAS levels increased by 16.5 percent for both the men and women; plasma testosterone decreased among the men by 6.8 percent (there was no effect among the women); and plasma estradiol levels were not effected for either gender.
Although these findings indicate that increased plasma DHEAS levels may, in part, help to explain the protective cardiovascular effects of moderate alcohol consumption, said Hendriks, "the exact biological mechanisms involved have not yet been established, which does not allow one to comment on the significance of our results. Our findings do, however, strengthen the relation between moderate drinking and an increase in DHEAS. The absence of an effect on estradiol has to be considered somewhat more carefully, because negative results may be caused by an insufficient number of people studied."
"I think that it's likely that, given this research and research that has come before, than alcohol does impact hormones," noted Rimm, "but I think that it probably doesn't impact hormones the same way in everybody. For example, it may be that someone's existing body weight may impact how strong the association is between alcohol and its effects on hormones, because hormones are related to obesity. I think it would be valuable to repeat this study in a much larger population, and look at other factors which can help differentiate how alcohol impacts hormones." Rimm also suggested looking at the effects of different kinds of alcoholic beverages, such as wine and spirits.
Hendriks said that his future research will focus on the effects of moderate drinking on HDL cholesterol functioning and inflammatory processes. "We will also study in detail the effects of moderate drinking on insulin sensitivity, because more and more epidemiological studies show that moderate drinking also protects against diabetes mellitus type II," he said.
Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper, "Effect of moderate alcohol consumption on plasma DHEAS, testosterone and estradiol levels in middle-aged men and postmenopausal women: a diet-controlled intervention study," were: Aafje Sierksma of the Department of Nutritional Physiology at TNO Nutrition and Food Research, and the Julius Center for Health Sciences and Primary Care at University Medical Center Utrecht, both in The Netherlands; Taisto Sarkola and CJ Peter Eriksson of the Department of Mental Health and Alcohol Research at the National Public Health Institute in Finland; Martijn S. van der Gaag of the Department of Nutritional Physiology at TNO Nutrition and Food Research; and Diederick E. Grobbee of the Julius Center for Health Sciences and Primary Care at University Medical Center Utrecht, The Netherlands. The study was funded by the Dutch Foundation for Alcohol Research.