Healthcare (Commonwealth Union) – Alcohol consumption during the earliest stages of embryonic development has been shown to alter gene regulation and disrupt cellular metabolic processes. In lab-based experiments, researchers observed that the initial nerve cells formed in the embryo are especially vulnerable to alcohol exposure. These findings reinforce current medical advice to avoid alcohol even while trying to conceive.
During the highly controlled process of gastrulation, embryonic cells divide and specialize into three primary layers — the endoderm, mesoderm, and ectoderm — which later develop into all body tissues and organs. The late and esteemed developmental biologist Lewis Wolpert famously pointed out that it is not birth, marriage, or death, but gastrulation which is truly the most significant time in our life. Gastrulation takes place around week 5 of pregnancy, often before many women realize they are expecting.
Gastrulation is a crucial part of early embryonic development — a stage that changes a simple, single-layered blastula into a complex, multi-layered structure known as the gastrula. This transformation lays the groundwork for the formation of every organ and tissue in the body.
Based on estimates from the Finnish Association on Intellectual and Developmental Disabilities, between 600 and 3,000 children are born annually in Finland with lasting harm linked to prenatal alcohol exposure. However, the actual figure may be higher due to the complexities involved in diagnosis.
A research team from the University of Helsinki, in partnership with the University of Eastern Finland, has recently investigated how alcohol affects this early, hard-to-research phase of human development.
In the experiment, pluripotent embryonic stem cells were cultured and guided to develop into the three fundamental germ layers. These cells were then treated with two varying levels of alcohol: a lower concentration of under one per mille, and a higher one exceeding three per mille. The scientists examined how alcohol influenced gene expression, epigenetic markers that control gene activity, and overall cellular metabolism.
Greater alcohol exposure led to more pronounced alterations compared to the lower dose, showing a clear dose-dependent effect on both gene function and metabolic processes. The most notable metabolic disruptions were found in the methionine cycle within the cells.
Doctoral researcher Essi Wallén indicated that the methionine cycle generates essential methyl groups that attach to DNA and help regulate gene activity and the changes they observed highlight how critical this form of epigenetic regulation is in the damage caused by alcohol exposure.
Researchers of the study highlighted that fact that the most significant effects of alcohol exposure were noticed in ectodermal cells—the precursors to the brain and nervous system when embryonic development takes place. Prenatal exposure to alcohol is widely recognized as a leading contributor to neurodevelopmental disorders.
“Many of the developmentally important genes altered in this study have previously been linked to prenatal alcohol exposure and its associated features, such as defects in heart and corpus callosum development, as well as holoprosencephaly, a failure of the forebrain to divide properly,” explained the Associate Professor Nina Kaminen-Ahola, who led the study.
The study suggests that certain developmental disorders linked to alcohol exposure may begin forming in the earliest weeks of pregnancy, a critical period when even slight disruptions in gene activity can alter developmental pathways. Still, additional research is required to determine how accurately the cellular model and alcohol levels used in the study reflect real-world human exposure.
This study is one component of a larger research initiative aimed at understanding how alcohol interferes with early human development and its long-term health consequences. Exposure to alcohol prior to birth is known to bring about to a spectrum of developmental conditions collectively known as fetal alcohol spectrum disorders (FASD).
