Tequila is a distilled spirit originating from Mexico, made exclusively from the fermented sugars of the blue agave plant (Agave tequilana Weber). Like all alcoholic beverages, its physiological effects are primarily driven by the absorption of ethanol into the bloodstream. This process begins almost immediately upon consumption, as alcohol molecules traverse the stomach lining and small intestine to reach the circulatory system. The body’s reaction to this influx of ethanol dictates both the short-term experience and the long-term consequences associated with drinking this spirit.
Immediate Physiological Effects
The effects of tequila are felt rapidly because ethanol is a small molecule that passes quickly through the blood-brain barrier. Once inside the central nervous system (CNS), it acts as a depressant, fundamentally altering the communication pathways between neurons. Ethanol achieves this by interacting with two main types of neurotransmitter receptors: GABA and glutamate.
It enhances the activity of gamma-aminobutyric acid (GABA), the brain’s primary inhibitory neurotransmitter, increasing the dampening effect on neural activity. This potentiation of GABA receptors is responsible for feelings of relaxation, sedation, and the characteristic slowing of reaction time associated with intoxication. Simultaneously, alcohol suppresses the function of glutamate receptors, which are responsible for excitatory signals.
By inhibiting the brain’s main accelerator (glutamate) and boosting its main brake (GABA), ethanol impairs cognitive functions like judgment, memory formation, and motor coordination. The visible signs of intoxication, such as slurred speech and unsteadiness, are direct results of this combined neurological slowdown. The speed of these effects depends on factors such as consumption on an empty stomach, which allows for faster absorption from the small intestine.
The Chemistry of Tequila and Metabolism
The belief that tequila has unique chemical properties different from other spirits often focuses on its non-ethanol components. The agave plant contains agavins, which are fructans—a type of carbohydrate that can function as a prebiotic fiber. However, the cooking, fermentation, and distillation process converts nearly all agavins into fermentable sugars and subsequently into ethanol, meaning they are not present in the finished spirit.
The true chemical difference lies in congeners, which are non-ethanol compounds created as byproducts during fermentation and aging. Tequilas, especially those aged in wooden barrels like Reposado and Añejo, often contain a slightly higher concentration of these compounds than highly filtered spirits like vodka. Congeners contribute to the spirit’s distinct aroma, flavor profile, and color, and they also influence the body’s metabolic response.
The popular myth of a “worm” being a sign of authentic tequila is entirely false and was an early marketing tactic. The larvae, typically a gusano de maguey moth larva, is sometimes found in bottles of mezcal, tequila’s cousin spirit, but it has never been a traditional component of tequila itself. The spirit’s profile is defined by its distillation process and the presence or absence of trace compounds.
Acute Negative Aftermath
The negative effects experienced the morning after heavy consumption, commonly known as a hangover, are a complex reaction involving multiple physiological processes. A primary contributor is dehydration, resulting from ethanol’s action as a diuretic. Alcohol inhibits the release of vasopressin, a hormone that signals the kidneys to conserve water, leading to increased urination and significant fluid loss.
The liver’s attempt to process consumed ethanol generates a highly toxic intermediate compound called acetaldehyde. This substance is significantly more poisonous than ethanol itself and causes symptoms like nausea, headache, and flushing. The body must then break down acetaldehyde into the relatively harmless acetic acid, but excessive alcohol intake can overwhelm this process.
Furthermore, the presence of congeners in darker, aged tequilas (Reposado and Añejo) may exacerbate the severity of a hangover compared to clear, unaged Blanco tequilas. The overall metabolic strain, combined with an inflammatory response and a disruption of sleep cycles, culminates in the full range of debilitating hangover symptoms.
Long-Term Systemic Impact
Chronic and excessive consumption of any alcoholic beverage, including tequila, leads to cumulative and damaging effects across multiple organ systems. The liver, the main site of ethanol metabolism, is particularly vulnerable to long-term abuse. Persistent heavy drinking can lead to the accumulation of fat in liver cells, progressing to alcoholic hepatitis and eventually to cirrhosis, where scar tissue replaces healthy liver tissue.
The cardiovascular system is also placed under strain, with chronic abuse contributing to elevated blood pressure (hypertension) and a weakening of the heart muscle, known as cardiomyopathy. This damage impairs the heart’s ability to pump blood effectively throughout the body.
In the brain, long-term alcohol exposure can lead to structural changes, including a reduction in brain volume and the impairment of cognitive functions, memory, and coordination. Alcohol dependency and addiction are significant neurological consequences of sustained heavy consumption. The risk of various cancers, including those of the liver, throat, and esophagus, is also increased due to the carcinogenic nature of acetaldehyde.