The most commonly used intoxicating substance today is alcohol. Alcohol is an organic compound. It can be defined as a compound comprised of naturally occurring elements with carbon atoms. The most common members of the alcohol family include ethanol and methanol. The alcohol in a beverage is ethyl alcohol or ethanol. Molecularly, this is H3C2-OH. The OH group at the end of the group of molecules is what makes the compound an alcohol.

When alcohol gets ingested into the body, it passes from the stomach into the small intestine. Here, it gets absorbed by the blood and transposed throughout the body. Because of the quick pace in which alcohol moves through the body, it can reach and affect the central nervous system even in small concentrations. The more alcohol ingested, the more it will impact the central nervous system. It will act as a central nervous system depressant. The functioning of the central nervous system is greatly effected by alcohol. Also, it is proportionately affected by the amount of alcohol consumed.

Alcohol impairs each of the functioning systems of the body differently. Alcohol consumption can cause the central nervous system to impair many skills. The affects of alcohol include impaired motor skills, decrease inhibitions, impair judgment and body control, induce mental confusion, vomiting, tiredness and respiratory arrest. These issues could result in death. Many people in the United States know their limits and control their alcohol intake without problems.

Alcohol enters the body through absorption. This is the first stage of a three stage process of absorption, distribution and elimination. The three processes happen simultaneously. But, absorption happens first, as it is necessary to introduce the alcohol into the body.

Alcohol Absorption

Absorption of alcohol is the process by which alcohol is transferred from outside the body to the stomach, small intestine and then throughout the body through the bloodstream. Once ingested, alcohol is constantly absorbed into and eliminated from the body. The rate of absorption is variable. It is affected by many factors. This includes the presence of food in the stomach, food composition, the alcohol concentration of the beverage consumed, the rate of consumption, uptake from the stomach and duodenum, emotional state, and the time of day.

Ingested alcohol not yet absorbed from the stomach and intestines has no neurological effects. This means that it cannot cause driving impairment. Conversely, fully absorbed alcohol may cause driving impairment, if at a level which impairs driving. The timeframe in which alcohol is absorbed into the bloodstream and the corresponding volume absorbed are important in predicting an ultimate blood alcohol concentration.

Alcohol Content

Beverage

Alcohol Content (%)

Beers (lager)

3.2 – 4.0

Ales

4.5

Porter

6.0

Stout

6.0 – 8.0

Malt liquor

3.2 – 7.0

Sake

14.0 – 16.0

Table wines

7.1 – 14.0

Sparkling wines

8.0 – 14.0

Fortified wines

14.0 – 24.0

Aromatized wines

15.5 – 20.0

Brandies

40.0 – 43.0

Whiskies

40.0 – 75.0

Vodkas

40.0 – 50.0

Gin

40.0 – 48.5

Rum

40.0 – 95.0

Tequila

45.0 – 50.5

The gastrointestinal tract is the main source for absorbing alcohol, although it is absorbed by different parts of the body through blood diffusion. Also, the small intestine has a large surface area. It is the most efficient part of the tract for alcohol absorption. In a person with an empty stomach, peak blood alcohol concentrations get achieved on average 0.75 to 1.35 hours. This depends upon the dose and last meal and those without an empty stomach exhibit peak blood alcohol concentrations between one and six hours. But, this happens on average between 1.06 and 2.12 hours depending on quantity consumed and most recent meal.

The ingestion of food will slow the absorption of alcohol into a person’s bloodstream. The pyloric valve will close off the bottom of the stomach to contain the food ingested. This blocks the alcohol from reaching the small intestine. The alcohol will still absorb through the lining of the stomach. But, this process is much slower, and the alcohol suppressed within the stomach gets eliminated from the body at a faster rate.

The Effect of Alcohol on the Body

The small intestine has a large surface area and is the most efficient part of the tract for alcohol absorption. In a person with an empty stomach, peak blood alcohol concentrations are achieved on average 0.75 to 1.35 hours depending upon dose and last meal and those without an empty stomach exhibit peak blood alcohol concentrations between one and six hours, but on average between 1.06 and 2.12 hours depending on quantity consumed and most recent meal.

Food

The ingestion of food will slow the absorption of alcohol into a person’s bloodstream. The pyloric valve will close off the bottom of the stomach to contain the food ingested therefore blocking the alcohol from reaching the small intestine. The alcohol will still absorb through the lining of the stomach, but this process is much slower, and the alcohol that is suppressed within the stomach is eliminated from the body at a faster rate.

Medication

Any medications that you are taking can increase the effects of alcohol, so be sure to check the labels on the medications or consult a physician before drinking and taking medication. Some medications will react violently when combined with alcohol and antibiotics may become ineffective when taken in combination with alcohol.

Type of Alcohol

The different types of alcohol that a person ingests can affect the consumption rate due to the difference in the actual concentrations of alcohol in different alcoholic beverages. So, if a drink has an alcohol concentration between 10% and 30% such as beers, malt liquor and many table wines, they get absorbed more quickly than those above 30% and below 10%. This often plays a role in the increasing blood alcohol level after a person ingests a shot prior to leaving the social event. The shot will absorb much slower than the beer they may have been drinking, and may increase a person’s blood alcohol level while the person is in police custody.

Also, those drinks with lower alcohol tend to get missed by the body while in the gastrointestinal tract and they absorb very slow and large quantities can delay the process of gastric emptying. Amounts higher irritate the mucous membranes causing increased secretion of the mucous and again slowing the process of gastric emptying. Therefore, two people with similar body types can drink the same amount of alcohol but if the individuals are of different weights then one will have a larger percentage of water in the body and therefore will become intoxicated less quickly. An individual with more muscle mass will most likely be less affected than someone with a higher body fat content due to the fact that fatty tissue does not contain very much water and will therefore not absorb much of the alcohol.

Impairment

At any particular blood alcohol content, a driver may face significantly less impairment than another due to a greater tolerance to the effects of alcohol. For this reason, a driver’s apparent sobriety as seen through an obvious lack of impairment or a demonstration that the driver could perform tasks in a sober manner, sometimes may be used as evidence to rebut an incriminating blood alcohol test result.