Tuesday, January 9, 2007

ALCOHOL: WHY & HOW

The most commonly used intoxicating substance in society today is alcohol. Alcohol is an organic compound, which can be defined as a compound that is 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, which molecularly is H3C2-OH. The OH group at the end of the group of molecules is what makes the compound an alcohol. When alcohol is ingested into the body, it passes from the stomach into the small intestine where it is then absorbed by the blood and transposed throughout the body. Because of the quick pace that alcohol moves throughout the entire body, it can reach and affect the central nervous system even in small concentrations. The more alcohol that is ingested, the more it will impact the central nervous system and act as a central nervous system depressant. The functioning of the central nervous system is greatly effected and 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 motor skills, decrease inhibitions, impair judgment and body control, induce mental confusion, vomiting, tiredness and respiratory arrest, which could result in death. For the most part, people in the United States know their limit and control their alcohol intake without problems.
Alcohol enters the body through absorption, which is the first stage of a three stage process of absorption, distribution and elimination. The three processes happen simultaneously, with absorption happening first, as it is necessary to introduce the alcohol into the body.
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 and is affected by the presence of food in the stomach, food composition (carbohydrates or fats), 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 that has not yet been absorbed from the stomach and intestines has no neurological effects and cannot cause driving impairment. Conversely, alcohol that has been fully absorbed may cause driving impairment, if at a level which impairs driving. Consequently the timeframe in which alcohol is absorbed into the bloodstream and the corresponding volume absorbed are matters of great significance in predicting an ultimate blood alcohol concentration.
The gastrointestinal tract is the main source for absorbing alcohol, although it is absorbed by different parts of the body through blood diffusion. 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.
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.
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.
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. If a drink has an alcohol concentration between 10% and 30% such as beers, malt liquor and many table wines, they are 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 he or she may have been drinking, and may increase a person's blood alcohol level while the person is in police custody. Those drinks with lower alcohol content tend to be 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 water in the body and therefore will become intoxicated less quickly.
The blood alcohol concentration within a person's body is a function of the total amount of alcohol in one's body systems divided by the total body water. 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. At any particular blood alcohol content, a driver may be significantly less impaired 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.
Gender can also play a part in the elimination of alcohol. On average, women tend to eliminate alcohol at a rate that is 10% greater than men do. When a person has prolonged or heavy use of a drug, a tolerance is developed, and therefore, it is eliminated at a faster pace. There are two types of tolerance that men and women should understand. The first is functional tolerance that can be described as a change in the organ or the system's sensitivity to Two Types Of Tolerance:

Functional Metabolic

This is seen with chronic users of alcohol where their system and organs have adapted to the abuse the chronic user has done over the years to the body that their body has a functional tolerance to accept twice that of an average person. The second type of tolerance is called metabolic tolerance. Chronic users of alcohol can develop this type of tolerance and will allow the rate of the metabolism of alcohol rise to a level that is 72% faster than the average person. In this tolerance, the person's body is constantly creating alcohol dehydrogenate, an enzyme which enables the body to process alcohol. Although chronic users can handle larger quantities of alcohol, studies have shown that they still have impairment at the .08% BAC level. Elimination of alcohol is processed by the liver, the last stop in the in the absorption and elimination process of alcohol. The majority of alcohol that is ingested is eliminated through normal body metabolism and the remainder is eliminated through excretion in one's breath, urine, sweat, feces, and saliva. A normal person will eliminate alcohol at a rate of .5 oz of alcohol every hour, however, there are things that can affect that rate. Alcohol elimination rate is inversely proportionate to the concentration of alcohol within the blood. If the concentration of alcohol is extremely high or low, the rate at which the body eliminates the alcohol tends to be much faster. As a person gets older, their ability to metabolize alcohol diminishes, but alcoholics still tend to metabolize alcohol in their bodies much faster. If an individual consumes alcohol at a rate faster than the rate of elimination this will result in a higher blood alcohol concentration for a longer period of time.

1 comment:

Mel ANDREWS said...

I am very grateful for your blog on the functioning of the pyloric valve which confirms the BBC program "The Truth About Food". I organise whisky tastings and am concerned that participants maximize conditions to inhibit the intestinal (and blood vessel)absorbtion of alcohol.

M. Andrews, Belgium