The question of whether alcohol affects a person differently at high elevations, such as those found in Colorado, is common for visitors. This popular belief suggests that the intoxicating effects of a drink are more potent or occur more rapidly far above sea level. This phenomenon involves the intersection of human physiology and the physical environment, specifically the reduced atmospheric pressure and lower oxygen availability at elevations typically above 5,000 feet.
The Impact of Hypoxia on Impairment
The intensified feeling of intoxication experienced at high altitude is primarily due to hypoxia, a physiological state where the body is deprived of adequate oxygen supply. At elevations like those in Denver (over 5,280 feet), the partial pressure of oxygen is significantly lower than at sea level, meaning less oxygen is taken in with every breath.
The brain is especially sensitive to oxygen deprivation. Early stages of altitude exposure can produce symptoms similar to mild inebriation, including headache, dizziness, and a reduction in cognitive function. Alcohol is classified as a central nervous system (CNS) depressant, meaning it actively slows brain function.
When alcohol is introduced into a system already experiencing the depressant effects of hypoxia, the impairment is exaggerated through an additive effect. The combination of pre-existing oxygen deprivation and the further slowing of brain activity by alcohol results in functional impairment disproportionate to the amount consumed. The brain is doubly affected by two separate depressant factors acting simultaneously. This explains why one drink at a high elevation can feel like two drinks taken at sea level.
Alcohol Metabolism and BAC at Altitude
A common misconception is that the body metabolizes alcohol faster or slower at altitude, leading to a more rapid increase in Blood Alcohol Content (BAC). Alcohol metabolism occurs primarily in the liver, where the enzyme alcohol dehydrogenase breaks down ethanol. Scientific studies indicate that the rate at which a healthy liver processes alcohol is not fundamentally altered by high elevation.
A person’s BAC is determined by the amount of alcohol consumed, time elapsed, and individual factors like body weight and gender, not the surrounding air pressure. Research comparing BAC levels in individuals drinking the same amount of alcohol at sea level and at high altitude has shown similar concentrations. This suggests that the speed at which a person gets “drunk” in terms of measurable BAC is not dramatically affected by elevation.
It is important to distinguish between the rate of alcohol processing and the perceived effect of intoxication. While the liver clears the alcohol at the same speed, the brain’s heightened sensitivity due to hypoxia means that a standard BAC level results in a more profound degree of functional impairment. Therefore, the feeling of being “drunk faster” accurately describes the perceived effect, but not the underlying metabolic rate.
Practical Steps for Moderation at High Elevation
Given the intensified effects of alcohol at high elevation, visitors should adopt specific strategies for a safer experience. The primary step is to prioritize hydration, as the dry air and increased respiratory rate accelerate fluid loss. Alcohol acts as a diuretic, further compounding dehydration and worsening the physical effects of both altitude and alcohol.
A practical approach involves significantly reducing the typical amount of alcohol consumed. Experts recommend cutting the usual intake in half, especially during the first few days of acclimation, to account for the exaggerated impairment caused by hypoxia. Pacing consumption and alternating each alcoholic drink with a glass of water helps maintain proper hydration and slows the rate of alcohol intake.
Visitors must also be vigilant in distinguishing the symptoms of intoxication from those of acute mountain sickness (AMS). Symptoms such as headache, nausea, and dizziness are common to both, and alcohol can easily mask or exacerbate the signs of AMS. Refraining from alcohol completely for the first 24 to 48 hours after arriving above 5,000 feet allows the body time to begin acclimatization without the added stress of a CNS depressant.