What is the effect of alcohol at the cellular level?

From the Guidelines

Alcohol's primary effect at the cellular level is to disrupt cell membranes and interfere with cellular processes, leading to damage and altered function, as evidenced by the most recent study in 2020 1. The impact of alcohol on cells is multifaceted, affecting various organs and systems within the body. When consumed, ethanol easily passes through cell membranes due to its small size and solubility in both water and fat. Inside cells, alcohol alters membrane fluidity, damages proteins, and disrupts normal cellular functions.

• In the brain, alcohol enhances inhibitory neurotransmitters like GABA while blocking excitatory ones like glutamate, leading to the typical depressant effects.
• Alcohol also damages mitochondria, reducing cells' ability to produce energy, and generates harmful reactive oxygen species that cause oxidative stress.
• In the liver, alcohol metabolism produces toxic acetaldehyde, which forms protein adducts that trigger immune responses and cellular damage, as supported by the study in Hepatology 1. Long-term exposure to alcohol leads to adaptation through cellular tolerance mechanisms, but this contributes to dependence. Additionally, alcohol interferes with DNA repair mechanisms and can alter gene expression, potentially leading to lasting cellular changes even after alcohol consumption stops. The most recent and highest quality study, published in 2022, emphasizes the importance of limiting daily alcohol consumption to minimize health risks, with risks present even at 1 to 2 standard drinks per day 1. Key points to consider include:
• The definition of a standard drink, which contains 14g of alcohol, equivalent to 12oz of beer, 5oz of table wine, or 1.5oz of distilled spirits 1.
• The upper limit of safe drinking, which appears to be one standard drink per day for women and two standard drinks for men, although some analyses suggest limiting alcohol use to one drink per day for both men and women, or even avoiding alcohol altogether due to potential adverse health consequences 1.
• The pathophysiology of alcohol-related liver disease, which involves the accumulation of fat, changes in gut permeability, and activation of the innate immune response, leading to liver cell inflammation, injury, apoptosis, and necrosis 1.

From the Research

Effects of Alcohol on Cellular Level

The effects of alcohol at the cellular level are complex and multifaceted.

• Alcohol affects the function of various neuronal systems, including GABA, glutamatergic, serotonergic, dopaminergic, cholinergic, and opioid systems 2.
• At the neurochemical level, alcohol can affect these systems directly or indirectly by altering the interactions between them 2.
• The behavioral consequences of alcohol's actions on brain neurochemistry are dose- and time-related, and can change significantly even on the rising and falling phases of the blood ethanol curve 2.
• Alcohol use can produce wide-ranging and diverse effects on the central nervous system, influencing intracellular signaling mechanisms and leading to changes in gene expression, chromatin remodeling, and translation 3.
• These molecular alterations can affect the activity of neuronal circuits, producing long-lasting cellular adaptations in the brain that can drive the development and maintenance of alcohol use disorder (AUD) 3.

Cellular Adaptations and Organ Damage

• Chronic alcohol abuse can lead to pathophysiological changes that result in life-threatening clinical outcomes, affecting multiple organs including the liver, heart, pancreas, and central nervous system 4.
• Alcohol abuse can cause cellular damage and dysfunction in various organs, leading to conditions such as cirrhosis of the liver, diabetes, osteoporosis, arthritis, kidney disease, and immune system dysfunction 4.
• The nutritional effects of alcoholism are also significant, with alcohol affecting energy and protein metabolism, and contributing to organ toxicity and weight management issues 5.

Key Findings

• The effects of alcohol on the cellular level are influenced by factors such as dose, pattern of consumption, and individual genetic and demographic characteristics 2, 6.
• Low-to-moderate alcohol use may have some positive effects on cardiovascular health, but these must be weighed against the potential negative effects of alcohol use on other organs and systems 6.
• Further research is needed to fully understand the effects of alcohol on the cellular level and to develop effective treatments for alcohol use disorder and related conditions 3, 4.