There are many factors that affect the rate of alcohol absorption by the body. These factors can influence an individual’s ability to determine their level of inebriation and can influence their decision to operate a motor vehicle.
BAC and Functional Abilities
Alcohol consumption impacts an individual’s vision, reaction time, cognitive function, and ability to manage the complex operation of a motor vehicle. The higher an individual’s blood alcohol concentration (BAC) level, the greater the impact on their ability to safely drive their vehicle. However, because the rate of alcohol absorption can vary greatly, an individual may not be aware that they are inebriated when they get behind the wheel. This mitigating factor should always be discussed with a MN DWI lawyer prior to entering a plea or accepting a plea agreement.
Average Rates of Alcohol Absorption and Elimination
Alcohol is metabolized similarly to the way the body processes food. As it is processed, it generates carbon dioxide, which is excreted through the respiratory system. It is this factor that makes it possible for MN law enforcement to conduct breathalyzer testing.
The median rate of alcohol absorption is considered to be between 10 to 15 milligrams of alcohol per hour. Some individuals are able to process alcohol at a rate of as much as 18 milligrams per hour.
Factors that Increase Inebriation
Body Size & Structure — Individuals with smaller stature become inebriated faster than those with larger body composition. Contrary to popular myth, being “fat” doesn’t make anyone less likely to get drunk. Indeed, alcohol is not absorbed by adipose tissue. However, having more muscle mass and soft tissue does make it possible for the body to absorb greater quantities of alcohol.
Caffeine & Carbonation — Fizzy mixed drinks made with soda, or alcoholic drinks mixed with energy drinks or coffee are quickly absorbed into the bloodstream. Moreover, the energizing effects of the caffeine within these drinks masks the depressive effects of the alcohol, thus making someone who is drunk feel and appear as if they are sober.
Illness — Individuals who are sick with a cold or flu, and those who are afflicted with more serious conditions such as MS or cancer, are quicker to become inebriated than individuals who are in good health. For those whose immune systems are otherwise preoccupied, having even one drink could be enough to send them over the legal limit.
Medications — Many over-the-counter medications interact with alcohol and affect the body’s ability to metabolize it. Drugs such as aspirin, acetaminophen, and ibuprofen are the most common drugs taken by individuals whose BAC levels are over the limit.
Hormones — Individuals with thyroid conditions that suppress hormone production, or women who are menstruating or taking birth control pills can experience higher-than-normal BAC levels after a single drink.
Lack of Sleep — Sleep deprivation can negatively impact one’s ability to process alcohol. For example, if an individual sleeps less than 5 hours a night for a week, two drinks can have the same effect as six drinks would have on an individual who is getting 8 hours or more of sleep per night.
Genetics — Enzyme production can vary considerably between individuals of different ethnicities. Individuals who possess lower levels of alcohol dehydrogenase do not process alcohol as quickly as those who have higher concentrations of this enzyme within the blood.
Tolerance — It is possible for individuals to “train” the body to process alcohol at different rates. Individuals who drink more can process more alcohol, a condition often referred to as “alcohol tolerance.” The individual must consume more alcohol to achieve the feeling of being tipsy, but they are not therefore sober.
BAC and the Passage of Time
Within typical social gatherings, the highest BAC rate is reached within 30 minutes following the consumption of a drink. However, this is highly dependent on the factors listed above. Moreover, this rate can be reached faster if the individual consumes drinks with higher alcohol content as these are more rapidly absorbed into the bloodstream. In some cases, it may be up to two hours following the completion of the last drink before all of the alcohol is fully absorbed into the bloodstream.
At two hours, the rate of absorption is equal to the rate of elimination. At this point, the BAC won’t change much, which is why it is referred to as the BAC plateau. Once the plateau is reached, the rate of elimination will begin to surpass the absorption rate until all the alcohol has been processed and distributed throughout the tissues and fluids within the body. In fact, during this stage, the amount of alcohol in the arterial blood is far greater than that within the venous blood.