Physiological Impacts of Alcohol

1. Physiological Impacts of Alcohol By C Kohn, Waterford Agricultural Sciences

2. Alcohol • Alcohol for consumption has the same molecular structure as fuel ethanol: CH3CH2OH • Alcohol is poisonous to the human body • Many of the effects associated with consuming alcohol are actually a result of either the toxic impact on the body or the body’s method of coping with the toxin • When alcohol is consumed, the body immediately tries to eliminate it. • Alcohol is also a drug and can form both dependency and addiction

3. Pathway of Alcohol • The route taken by alcohol during consumption is as follows: • Mouth & Esophagus – alcohol is diluted by saliva before being swallowed. Some is immediately absorbed • Stomach – more alcohol is absorbed here, irritating the lining of the stomach and increasing the acidity • Small Intestine – any remaining alcohol is passed here and is the site of most alcohol absorption • Bloodstream – alcohol quickly diffuses through the body, affecting almost all cells • Brain - these cells are more susceptible because they are usually protected from toxins by the blood-brain barrier • Liver – blood-alcohol is metabolized in two stages and then respired into CO2, H2O, and fatty acids. • Excretion via urine, the lungs, and sweat.

4. Steps of Metabolism • The metabolism of alcohol is the process in which the body converts alcohol into a less toxic substance. • Alcohol metabolism (processing) has three steps • Consumption – getting the liquid into your body • Absorption – absorbing the alcohol into your bloodstream • Processing – converting the I) alcohol into II) acetaldehyde , then III) acetate (or acetic acid) and finally into fatty acids, carbon dioxide, and water

5. Consumption • Consumption – mouth and esophagus • 20% of consumed alcohol is immediately absorbed into the bloodstream before reaching the rest of the gastrointestinal tract • Alcohol is an irritant to the sensitive lining of the esophagus • Excess consumption can significantly raise your risk of esophageal cancer

6. Absorption • Alcohol is absorbed into the blood through the stomach walls • The emptier the stomach, the faster the absorption, the greater the impact, and the more pronounced the side-effects • Absorption of alcohol also irritates the lining of the stomach, leading to some symptoms commonly associated with a hangover (nausea, vomiting, diarrhea) • This also accelerates productions of hydrochloric acid in the stomach, leading to the ‘upset stomach’ feeling common with consumption and/or hangover • If HCl secretion increases too rapidly or too high (or both), nausea and vomiting pathways are triggered. • If vomiting does not occur, diarrhea is more likely for the same reason • Alcohol not absorbed by the stomach is absorbed in the small intestine (where most absorption occurs)

7. Absorption • Once in the bloodstream, alcohol is rapidly distributed throughout the body • Different tissues absorb alcohol at differing rates • E.g. muscle absorbs alcohol more rapidly than fat • People with higher percentages of body fat will absorb alcohol less quickly, lengthening the time it circulates in the bloodstream • Women physiologically have a higher body fat percentage than men, typically increasing the impact of alcohol on their bodies • Body size also is a factor – the smaller the body, the more concentrated the effects will be (because alcohol will be a bigger proportion of the bodily fluid in a smaller person) • Rate of absorption is also affected by rate and type of consumption • Faster consumption, faster absorption • Carbonated beverages also increase the rate of absorption – includes champagne, wine coolers, and drinks made with soda

8. Processing • Alcohol is processed by the liver as it arrives from the bloodstream • The liver produces enzymes called alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). • Alcohol metabolism via ADH produces a secondary product more toxic than alcohol itself – acetaldehyde • Acetaldehyde is then converted into acetate by ALDH • Acetate is digested into fatty acids, CO2, and water • Fatty acids, when digested, create 7 calories per gram of alcohol • ‘Beer gut’ has some truth to it

9. Overview of Processing • Alcohol arrives at the liver via the bloodstream • ADH turns alcohol into acetaldehyde • This is the “bad” version • ALDH converts acetaldehyde into acetate • This is the “good” version that can be broken down • Acetate is converted into CO2, H2O, and fatty acids by liver cell mitochondria. If fatty acids accumulate too fast, cirrhosis can occur

10. Effects of Alcohol • Flushing (Red-Faced) • Disrupted Balance • Hangovers, Nausea, & Dehydration • Impaired Judgment • Amnesia • Anxiety • “Breaking the Seal” – Increased Urination

11. Impaired Judgment • Alcohol depresses the central nervous system • This means that alcohol slows the rate at which the nervous system can function and communicate • This will prevent all neurological processes from occurring at the normal rate or extent ranging from judgment to control of bodily function. • Structures of the brain affected include the frontal lobe where rational decision making and judgment occurs. • Consumption of alcohol will also cause increased self-confidence as well as decreased judgment – a very bad combination. • Those that are too drunk to drive are less likely to be able to make this determination as they drink more • Those that are too drunk too drive will also feel more confident in their own ability to safely do so (despite the contrary being true)

12. Amnesia • Because the central nervous system is impaired, the process of creating and storing memory is also impaired. • This can lead to short-term amnesia – excess alcohol consumption can cause people to be unable to form memories during consumption to varying extents.

13. Anxiety • Part of the brain, called the amygdala, regulates human emotion • The amygdala is responsible for creating emotion appropriate for a circumstance • Because alcohol depresses the central nervous system, the emotional regulatory function of the amygdala will also be impaired. • This can lead to anxiety, anger, frustration, lust, and other primal human emotions to become over- or under-expressed.

14. “Breaking the Seal” • “Breaking the seal” and Water Loss • A common myth associated with alcohol consumption is that if you urinate once, you will have to urinate constantly – this is called “breaking the seal” • In reality, you’ve ‘broken the seal’ as soon as you have your first sip • Alcohol affects urination in 3 major ways – • Alcohol is a diuretic, causing cells to shed water • Alcohol interferes with water reabsorption in the kidneys, causing excess water to be moved to the bladder • Alcohol causes stretch receptors ‘miscalculate’ the amount of urine in the bladder, making it feel fuller than it is. • A combination of excess water lost, reduced water reabsorption, and a miscalculating bladder creates the need to urinate more frequently with greater consumption.

15. Thinned Blood • Alcohol is a blood thinner • Alcohol has a lower density than water • This is why alcohol floats on top of water • Consumption and absorption of alcohol will reduce the thickness of your blood. • Moderate consumption of alcohol (< 2 drinks per day) by legal adults can actually improve heart health by lessening the work required to pump blood • Thinner blood is easier to pump • Do not self-diagnose!

16. Flushing • A common symptom of inebriation is flushing, or being “red faced” • Flushing in the face is due to an excess of acetaldehyde in the body, a decrease in the ALDH enzyme, or both. • Because acetaldehyde is more toxic to the body than the alcohol itself, it can cause an inflammation response similar to injury or infection in skin blood vessels.

17. Lost Balance • Balance is regulated by the semicircular canals inside your ear. • The semicircular canals are looped structures that are filled with fluid called endolymph • The movement of fluid inside these loops tells your body your position and orientation in space • Alcohol thickens this fluid, reducing theability to sense movement. • The sensory system responsible forsensing movement is now less sensitive, causing stumbling and loss of coordination and balance. • The cerebellum (muscle coordinationcenter of the brain) also is impaired

18. Hangovers • A hangover is the ill-effects experienced by excess alcohol consumption after the ‘high’ of alcohol has worn off. • Symptoms of a hangover include: • Fatigue • Dehydration • Nausea & Stomach Irritation • Headache

19. Fatigue • The exhaustion associated with excess consumption is due to alcohol’s inhibition of glutamine • Glutamine is a bodily stimulant whose production is inhibited by alcohol • When the effects of alcohol wear off, glutamine production is increased to compensate for previous inhibition • This causes a drinker to wake more in their sleep as glutamine production increases, preventing the deepest and most restful stages of sleep • Glutamine rebound can also lead to tremors, anxiety, and restlessness • Glutamine, like caffeine, is a stimulant • Excess glutamine production is goingto have effects similar to excess caffeine consumption

20. Dehydration • Alcohol is a diuretic and causes cells to shed water. • Alcohol also interferes with the kidney’s ability to regulate water balance in the body • Job of an aquaporin protein is to regulate reabsorption of water filtered out of the blood by the kidney. • Vasopressin is a hormone that regulates whether or not an aquaporin channel is open • Alcohol inhibits the function of vasopressin, limiting its ability to open aquaporin channels that would let filtered water back into the bloodstream • This causes water to be moved tothe bladder at an increased rate • This coupled with the diuretic effects of alcohol leads to a dehydrating effect when consumed Opened by Vasopressin

22. Nausea & Stomach Ache • Stomach Irritation is largely due to excess production of HCl in the stomach as a result of absorption into the bloodstream through the stomach lining. • Excess hydrochloric acid increases the acidity of the stomach, creating the ‘sour stomach’ feeling in a very literal way • If the pH of the stomach drops too much or too fast (or both), it will cause vomiting, diarrhea, or both. • This can also be caused by a ‘fight or flight’ response of the body due to the poisonous nature of alcohol

23. Headache • A headache can be due to numerous effects of alcohol, including – • Inflammation of blood vessels, creating pressure in the skull • Dehydration • Acetaldehyde’s presence in the blood • Increased stimulation and anxiety caused by glutamine resurgence • Stress from nausea • A combination of all these and more

24. Cures to a Hangover • There is only one truly effective cure to a hangover – TIME • Pain relievers that do not contain acetaminophen can lessen perceived pain but not actual damage (aspirin can cause increased liver damage) • Caffeine is a diuretic and will compound damage caused by water lost and dehydration • “Hair of the Dog” or drinking again in the morning to lessen a hangover, only worsens the problem while lessening the perception of it (for the time being)

25. Cures to Inebriation • Similarly, you cannot “sober up” with anything other than time. • Caffeine will not reverse the depression of the central nervous system, thicken your blood, restore your balance, or negate any other effects of inebriation • What’s worse, mixing an ‘upper’ with a ‘downer’ (caffeine with alcohol) can cause the brain to send conflicting signals to organs such as your heart and lungs. • Stimulant/alcohol combinations can lead to heart or lung failure. • Consuming food to sober up will not reduce the amount of alcohol already in your bloodstream • Additionally, you cannot ‘fool’ a blood alcohol meter.

26. Long Term Effects of Excess Consumption • Tissue damage – alcohol is an irritant to the mouth, throat, and stomach and can raise the risk of cancers to these structures • Liver Damage – the liver can be overwhelmed by fatty acid, causing it to swell and lose its ability to filter the body of other toxins • Brain damage – alcohol can permanently damage brain cells, particularly in brains that are still developing and maturing (the brain does not finish maturing until age 20-25). • Weight gain – alcohol has 7 calories per gram. This is almost as high as pure fat (9 cal) and higher than carbohydrates (4 cal/g) • Skin Damage – the conversion of alcohol into acetaldehyde causes inflammation. • Excess consumption will cause excess inflammation that can lead to the rupture of blood vessels in the skin creating blotchy scarring. • Accidents – impaired judgment, lost coordination, and an increased sense of confidence is a deadly and all-too-often fatal combination.

27. Review Concepts • How alcohol is treated by the body. • Similarities between fuel ethanol and alcohol for consumption. • Percent of alcohol absorbed by the mouth and esophagus. • How alcohol upsets the stomach. • How alcohol consumption affects men and women differently. • How alcohol is processed by the liver (including the enzymes needed and the intermediate forms of alcohol formed during metabolism by the liver). • Final products created by the metabolism of alcohol. • How alcohol affects: judgment; emotion; memory; the skin; balance; urination; fatigue; hangovers (include the effect on the primary structures needed for each consideration).