Tequila is a distilled spirit originating from Mexico, made from the fermented sugars of the blue agave plant. Like all alcoholic beverages, the fundamental effect tequila has on the body and brain is due to its primary component, ethanol. Once consumed, ethanol is quickly absorbed into the bloodstream, where it begins to influence various physiological systems. The unique experience associated with tequila is less about the alcohol molecule itself and more about the presence of other chemical compounds and the manner of consumption.
The Central Nervous System Response
Tequila functions as a central nervous system (CNS) depressant, slowing down brain activity. Ethanol achieves this by interacting with two main neurotransmitters in the brain: gamma-aminobutyric acid (GABA) and glutamate. It enhances the effects of GABA, which is an inhibitory neurotransmitter that reduces neural excitability, leading to feelings of relaxation and sedation.
Simultaneously, ethanol blocks the activity of glutamate, an excitatory neurotransmitter responsible for alertness and cognitive function. This dual action impairs motor coordination, alters perception, and reduces inhibitions as the depressant effects take hold. The perception that tequila is a stimulant is a common misconception, often stemming from the initial release of dopamine in the brain’s reward pathways, which provides a temporary feeling of euphoria and energy.
The high proof of tequila, typically around 40% alcohol by volume, contributes to a rapid onset of effects, especially when consumed quickly as a shot. This fast delivery system can make the subjective experience feel more intense compared to slower-sipped beverages with lower alcohol concentrations. Physical effects, such as slurred speech and sluggish reflexes, are directly tied to the concentration of ethanol in the bloodstream, which is rapidly achieved with concentrated spirits.
Unique Chemistry: The Role of Congeners and Agave
The distinct character of tequila is largely attributed to compounds known as congeners. These are minor chemical byproducts of the fermentation and distillation process, which include substances like methanol, acetone, and fusel oils. Congeners are responsible for the unique flavor, aroma, and color profiles of different alcoholic beverages.
The concentration of congeners varies significantly depending on the type of tequila and its aging process. Darker, aged tequilas, such as añejo and reposado, are stored in oak barrels, which introduce new compounds and generally result in higher congener levels. Clear tequilas, like blanco or silver, are typically bottled immediately or aged for a very short period, giving them a lower congener count compared to their darker counterparts.
The blue agave plant contains naturally occurring sugars called fructans, or agavins. While some people believe these agave-derived compounds provide unique effects, the distillation process converts nearly all of the fructans into ethanol. The final tequila spirit contains negligible amounts of these compounds, and they do not alter the fundamental depressant action of the alcohol.
How Tequila Interacts With the Digestive System
Ethanol is absorbed through the digestive tract, primarily in the small intestine, though about 20% to 25% is absorbed directly through the stomach lining. Because tequila is a high-proof spirit, it can irritate the delicate mucosal lining of the stomach, potentially causing inflammation, known as gastritis. Alcohol also stimulates the production of stomach acid, which can contribute to digestive discomfort and an unpleasant sensation.
High-concentration alcohol can accelerate the rate of gastric emptying, moving the alcohol into the small intestine faster. This rapid transit increases the speed at which ethanol enters the bloodstream, contributing to the quick onset of intoxication. Once in the blood, the liver begins the metabolic process, using the enzyme alcohol dehydrogenase (ADH) to convert ethanol into the toxic compound acetaldehyde.
Acetaldehyde is then rapidly broken down by a second enzyme, aldehyde dehydrogenase (ALDH), into acetate, which the body can harmlessly eliminate. While the agave plant contains fructans that function as prebiotics in their raw form, the high heat and fermentation involved in making tequila destroy most of these compounds. Therefore, the common claim that tequila is beneficial for the gut microbiome is largely overstated, as the irritant effects of the alcohol outweigh any residual prebiotic benefits.
Understanding the Tequila Hangover
The severity of a tequila hangover is often attributed to a combination of factors, not just the spirit itself. One of the most significant contributors is dehydration, as ethanol acts as a diuretic, increasing urine production and leading to fluid loss. This dehydration is responsible for classic hangover symptoms like headaches, dizziness, and intense thirst.
Congeners also play a role in exacerbating hangover symptoms, as the body must process these byproducts in addition to the ethanol. While the final product is highly distilled, the remaining congeners require additional metabolic effort, and their breakdown products can contribute to the overall feeling of malaise. For many people, darker tequilas, with their higher congener content, may result in a more intense hangover than clear spirits.
The third factor is the pattern of consumption: tequila is frequently consumed in rapid succession, such as through shots, which leads to a quick and high peak blood alcohol concentration. Consuming a large volume of alcohol in a short period overwhelms the liver’s ability to process the ethanol and congeners efficiently. This excessive intake, rather than a unique chemical property of the spirit, is often the primary reason tequila hangovers are perceived to be particularly severe.