University of Louisville School of Public Health and Information Sciences researcher Kira Taylor and her team analyzed data from more than 400 women for up to 19 months. The women completed daily diaries reporting how much alcohol they drank and what type.

Heavy drinking was defined as more than six alcoholic drinks a week, moderate drinking was three to six drinks a week, and binge drinking was defined as four or more drinks on a single day. A drink was defined as a third of a liter of beer, a medium glass of wine or just under a double shot of spirits. The researchers collected information on factors that could affect the results, such as age, medical history, smoking, obesity, intercourse frequency, use of birth control methods and intention to become pregnant.

“We found that heavy drinking during any phase of the menstrual cycle was significantly associated with a reduced probability of conception compared to non-drinkers,” Taylor said. “This is important because some women who are trying to conceive might believe it is ‘safe’ to drink during certain parts of the menstrual cycle.”

The research also found during the luteal phase, or the last two weeks of the menstrual cycle before bleeding starts and when the process of implantation occurs, not only heavy drinking but also moderate drinking was significantly associated with a reduced probability of conception. At the time of ovulation, usually around day 14 of the cycle, consuming a lot of alcohol – either heavy or binge drinking – was significantly associated with reduced chances of conception.

“If we assume that a typical, healthy, non-drinking woman in the general population who is trying to conceive has approximately a 25% chance of conceiving during one menstrual cycle, then out of 100 women approximately 25 non-drinkers would conceive in a particular cycle, about 20 moderate drinkers would conceive and only about 11 heavy drinkers would conceive,” Taylor said. “But the effect of moderate drinking during the luteal phase is more pronounced and only about 16 moderate drinkers would conceive.

“Our study only included a few hundred women and, while we believe the results strongly suggest that heavy and even moderate alcohol intake affects the ability to conceive, the exact percentages and numbers should be viewed as rough estimates,” she said.

Each extra day of binge drinking was associated with an approximate 19% reduction in the odds of conceiving during the luteal phase and a 41% reduction during the ovulatory phase. The researchers found no difference in their results between different types of drinks. The influence of drinking by male partners was not assessed.

While the study does not show that drinking alcohol causes the reduction in the chances of becoming pregnant, it does point to an association. Possible biological mechanisms to explain the association could be that alcohol intake affects the processes involved in ovulation so that no egg is released during the ovulatory part of the cycle, and alcohol could affect the ability of a fertilized egg to implant in the womb.

“The results in this study should not be construed to mean that drinking alcohol prevents pregnancy. In other words, alcohol is not birth control. Even if a woman drinks alcohol heavily, if she has unprotected intercourse, she can become pregnant,” Taylor said.

The UofL Center is one of only 20 in the nation. It’s funding score for the grant was the best in the nation, and it is the only center with a nutrition focus.

“We are going to take a unique focus into organ injury associated with alcohol use,” said Dr. Gregory C. Postel, interim executive vice president for health affairs at UofL. “Our researchers are going to examine the interactive role of nutrition and alcohol in the deleterious, as well as beneficial, effects of alcohol on the human body.”

Through four different projects, the research team led by Dr. Craig McClain, associate vice president for translational research and associate vice president for health affairs/research, has three specific aims:

1. Facilitate interdisciplinary approaches and serve as a regional/national resource for the study of nutrition and alcohol-induced organ injury;
2. Provide a robust pilot project program and comprehensive education and research training in order to develop the next generation of alcohol investigators; and
3. Develop potential therapeutic targets/interventions for alcohol-induced organ injury based on the mechanistic research of the center and translate knowledge/interventions to the community.

“This funding will allow us to look at the problems that alcohol abuse causes, as well as the potential benefits of alcohol,” McClain said. “Our focus on dietary nutrition and abuse is unique. For example, only a small proportion of people who abuse alcohol will develop liver disease. We believe that the type of dietary fat intake is critical in the development of alcohol-induced organ injury.”

To find answers, the center will initially focus on four projects.

Project 1 will evaluate the role of dietary unsaturated fat in the development/progression of alcoholic liver disease.

Project 2 will evaluate alcohol-induced alterations in the gut-liver axis. Researchers will examine the role of histone deacetylases (HDACs) in both the intestine and liver in alcohol-induced gut-barrier dysfunction and steatohepatitis and the role of probiotics and dietary HDAC inhibitors in preventing/treating experimental ALD.

Project 3 will determine mechanisms by which maternal alcohol consumption causes mental retardation in the offspring. Researchers will evaluate epigenetic mechanisms by which alcohol induces apoptosis and teratogenesis, and by which the nutraceutical, sulforaphane, provides epigenetic protection.

Project 4 will evaluate mechanisms by which alcohol causes increased susceptibility to acute lung injury. They postulate that chronic alcohol intake triggers extracellular matrix remodeling resulting in “repavement” of lung tissue with a proinflammatory extracelluar matrix and that this process can be modulated by dietary intervention.

“Our studies are designed to look at a number of organ systems, not just the liver,” McClain said. “Additionally, we are very interested in gaining a better understanding of the role alcohol may play during fetal development and the mechanisms associated with fetal alcohol syndrome.”

The research team spans 13 departments at UofL in six schools/colleges.

“One of the keys to developing the breadth of information we hope to achieve is bringing together people with expertise in areas that often are not combined,” McClain said. “It is important that we look at these issues from a broad perspective if we are to examine the overall impacts of alcohol.”

Here is more information about the Alcohol Research Center: