The Effects of Alcohol on Your Body

Look, I’m not your fifth grade D.A.R.E. instructor. I’m not here to make you put on a pair of drunk vision goggles and lecture you on how if you take one sip of alcohol, you’ll get sick and die. But this is a fitness blog and alcohol is widely enough consumed that it’s worth making a post about how it can affect your fitness. I am a big fan of red wine and an advocate of how it can be helpful to achieving your fitness goals. But there are also many negative effects to drinking and it is important to be aware of them. 

The first thing to think about is absorption. The levels of enzymes responsible for breaking down and metabolizing alcohol will vary from person to person, and will influence level of intoxication, illness after drinking and even likelihood of alcohol dependence. Many things affect alcohol’s absorption in the bloodstream. Distilled liquor gets absorbed fastest, followed by sparkling wine, then regular wine, then beer. 

With no food in the stomach, alcohol passes directly into your small intestine for rapid absorption into the bloodstream. The type of food in the stomach, stress, anxiety, fear and hydration can all affect the absorption rate. Alcohol also absorbs better in muscle than fat, so less remains in the bloodstream. When comparing two people of equal weight and alcohol consumption, the one with the higher body fat percentage will have a higher BAC (blood alcohol content.)

Next, one must look at the mechanism of action. Ethanol increases GABA’s inhibitory actions and release. With acute use, this can lead to sedation, reduced anxiety, and incoordination. Chronic use can lead to development of tolerance. In a region of the midbrain, ethanol increases dopamine release and enhances the rewarding effects of alcohol.

Alcohol decreases glutamate’s excitatory actions and reduces its release. Glutamate is involved with learning and memory, so ethanol’s antagonism may be responsible for memory loss. With long term use, the number of glutamate receptors increases and there is a rebound in glutamate release. Upon withdrawal, this could lead to harsh effects such as seizures and brain damage. Withdrawal from alcohol can reduce dopamine concentration, which may result in depression. 

People with a genetic predisposition for alcohol dependence have low baseline levels for endorphins, and release significantly more when given alcohol compared to people with no genetic predisposition. Chronic administration of alcohol may increase endorphin levels, leading to the dysphoria seen during withdrawal. Serotonin may also play a role in alcohol’s reinforcing effects. Those with low Serotonin are likely to drink more alcohol. 

Now here’s something you definitely didn’t hear in a D.A.R.E. seminar: the therapeutic uses of alcohol. Alcohol has a very low therapeutic index (quantitative measurement of the relative safety of a drug), yet more than 100 studies have shown that moderate drinkers live longer on average than non-drinkers. Moderate alcohol consumption is correlated with a reduced risk of death by cardiovascular disease, cancer and diabetes. 

Alcohol reduces the blood’s clotting tendency, raises HDL cholesterol (the “good” cholesterol), and improves insulin sensitivity, lowering risk of cardiovascular disease (Brien et al., 2011.) Benefits may be related to the stress reduction or vasodilation (the dilation of blood vessels, which decreases blood pressure) caused by alcohol.

It’s important not to overgeneralize the cardioprotective effects of alcohol. They depend on one’s sex, race, age and the amount consumed. The benefits of alcohol seem to exist in a very narrow window. Drinking between .5 and 1.5 drinks per day may reduce one’s risk of coronary heart disease but drinking two or more may increase the risk. Additionally, it’s possible that moderation in drinking could reflect healthy moderation in other aspects of life. 

Like it or not, alcohol is a part of modern society and is prevalent in many cultures. Though it is not something that is healthy to frequently consume, we must be mindful of it and try to maximize its health benefits, while minimizing the negative effects it can cause. There is still quite a bit more left to cover on this topic, so buckle in. 

The physiological effects of alcohol are quite apparent. Low or moderate consumption of ethanol is probably not harmful and may even have some minor beneficial effects. However, heavy drinking can be very dangerous and even lethal. Those who drink more than 14 drinks per week lose approximately 1.6% of brain size, compared to non-drinkers (Paul et al., 2007) It doesn’t take a physiologist to know that heavy drinking can be quite dangerous. But what many people don’t realize is that even moderate consumption can shrink the brain and cause cognitive decline.

Alcohol impairs decisions, judgements, and memory and also affects areas involved in motivation, reward, dependence, anxiety, and anger. Additionally, it reduces blood clotting and raises HDL levels, which is the good cholesterol that removes bad cholesterol for arterial walls. In non-diabetics, moderate consumption improves insulin sensitivity. Ethanol stimulates the gastric secretion of HCL and pepsin, substances that are necessary for digestion. However, at high doses, it can actually erode the stomach instead. 

And here’s another physiological effect that you may be all too familiar with, even if you’re not familiar with the science behind it. Alcohol inhibits the secretion of vasopressin (an important hormone), thus increasing urination.  Drinking about 250ml of an alcoholic beverage causes the body to expel 800 to 1000ml of water. That’s four times as much liquid lost, than gained. This leads to dehydration (no surprise there), one of the major causes of hangovers. 

And that’s not even getting started on the behavioral effects of drinking alcohol. In the words of author Erica Jong, the superego is soluble in alcohol. Self-perception and judgments are impaired by ethanol. It leads to suppression of the part of the cortex responsible for social and behavioral restraints. This means that people do things they normally wouldn’t such as having unsafe sex.

It gets worse from there. About one third of traffic crash fatalities are linked to alcohol use, and the risk of a fatal crash is dose-related. When people commit violent crimes (not necessarily DUIs), they are most often under the influence of alcohol. Alcohol is scientifically proven to increase the occurrence of aggression. People often turn to alcohol to mask emotional problems, but this has also been medically proven to be ineffective. Rather than solve the problems that lead to drinking, often times a dependence to alcohol is created, thus increasing the amount of problems. It’s a very unhealthy cycle. 

This leads me to the chronic effects of alcohol consumption. Long term heavy drinking is devastating to almost every organ, but there is no consistent definition of what “heavy drinking” entails, since everyone’s body is different. Over time, high doses of alcohol cause neurological damage and reduced brain weight. Heavy drinkers perform poorly on tests of abstract thinking, problem-solving, memory, attention, concentration, learning, perception of emotions, and perceptual motor speed. 

Again, it gets a lot worse. Alcohol consumption increases the risk of many, many, cancers. The metabolism of ethanol promotes tumor growth. When alcohol and tobacco are used together, this increases one’s risk of oral cancer 15 times above the rest for people who do not smoke or drink. 

It gets particularly bad for your liver. The liver normally metabolizes fatty acids, but if alcohol is present, the liver metabolizes it first, causing fat to accumulate. This can rupture and kill liver cells. Eventually, heavy drinkers will develop hepatitis, which is characterized by the inflammation and death of liver cells. Alcoholic cirrhosis develops gradually. Inflammation leads to irreversible scar tissue, replaces healthy liver cells, and blocks blood vessels that supply the liver with oxygen, leading to further cell death. 

There are also the reproductive effects. Alcohol use enhances interest in sex but impairs physiological arousal. Cruel, huh? In men, usage is associated with reduced testosterone, less sperm and semen production, testicular atrophy, diminished erections, ejaculatory incompetence/impotence, and loss of sexual desire. Gynecomastia, the abnormal enlargement of a man’s breasts, occurs because liver damage causes estrogen to be reabsorbed into blood. 

Men are not the only sex to suffer from reproductive effects of alcohol use. Female heavy drinkers are likely to experience painful intercourse and vaginal dysfunction, menstrual disorders, early onset of menopause, reduced libido, and infertility (Jenczura et al., 2018.) Prenatal alcohol exposure can lead to fetal alcohol spectrum disorder. 

It’s also worth mentioning the dangers of mixing alcohol with caffeine. Many people believe that caffeine obers you up. This is medically false. Although caffeine may speed up reaction time, it doesn’t reduce impairment. Compared to students who consume alcohol without caffeine, those who do report more alcohol-related risk behaviors including drunk driving, riding with intoxicated drivers, being involved in alcohol-related vehicle crash, and committing sexual assault. 

I’ve talked about some of the fatal risks of consuming too much alcohol. They are certainly worth mentioning, but there are also smaller, but quite significant ways in which it can prevent you from achieving your fitness goals. You’ve probably heard of the term “empty calories.” That’s exactly what alcohol is, to a t. Alcohol is a calorie dense (7 calories per gram), non-essential nutrient in liquid form, which means it can easily lead to excess weight gain, especially in the midsection. Mixed drinks also tend to contain high amounts of processed sugar, which can worsen hangovers and have more serious effects on health. 

I hope I was able to inform readers about the various risks of alcohol. Again, I didn’t write this to instill fear in anyone or to criticize people who choose to drink. I simply believe that people should be aware of what they put into their body and have as much information as possible when making choices about what to consume. And remember, moderation is key. If you have any more questions about alcohol, please leave a comment and I will be happy to address them. 



Brien, S. E. (2011, February 22). Effect of alcohol consumption on biological markers associated with risk of coronary heart disease: systematic review and meta-analysis of interventional studies. PubMed.

Dangers of mixing alcohol with caffeine and energy drinks | CDC. (2020). Cdc.Gov.

Drinking Heavy Amounts Of Alcohol Shrinks Your Brain. (2007). ScienceDaily.

Juergens, J., & Parisi, T. (2020, November 30). Alcohol-Related Crime. Addiction Center.

Red wine and resveratrol: Good for your heart? (2019, October 22). Mayo Clinic.,the%20formation%20of%20blood%20clots

Sexual Function of Postmenopausal Women Addicted to Alcohol. (2018, August 1). PubMed Central (PMC).

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