There is no doubt that most individuals understand the general impact of alcohol on the body such as its effects of memory and motor skills, but there are fewer people who understand the side-effects of alcohol on athletes in regards to recovery, sleep, metabolism, hormone regulation, and muscle building. The following text will give you a better understanding of alcohol's ramification on athletes and overall health.

​

What is Alcohol?

Alcohol used in beers and wines is called ethanol, otherwise known as ethyl alcohol. Ethanol is developed through yeast, sugar and starch fermentation. Impairment following alcohol consumption is a product of ethanol reacting with the central nervous system, blunting coordination and judgement. Ethanol is able to be metabolized in the liver in small quantities, too much alcohol can cause issues in the body.

​

The effects of alcohol on athletes vary between individuals and their personal traits, such as genetics, age, gender, body mass, overall health, nutrition status, and medical history of drug use. Quantity of alcohol consumed also determines effects of alcohol on the body. 

​

Some individuals preach that alcohol increases energy levels, energy production and increased recovery rates, but science supports the claims that alcohol is in fact not an ergogenic aid when it comes to athletic performance.

 

Acute vs Chronic Alcohol Use

Acute alcohol ingestion results in an increase in blood alcohol content (BAC), effecting motor skills - decreasing coordination, balance and reaction time, as well as decreases cognitive function, hydration levels, recovery and aerobic performance. Absorption and utilization of certain nutrients are inhibited and the small intestine's ability to absorb certain vitamins are restricted. Activation in the liver is impaired.

​

Chronic alcohol ingestion leads to the deterioration of the body's organs and has the potential to lead to nutritional deficiencies, restricted immune function - opening the body to illness along with poorer recovery, body composition issues, and can increase the risk of cardiovascular disease, liver disease, and certain types of cancers. Alcohol consumption has been linked to many forms of cancer including head and neck cancer, including oral cavity, pharynx, and larynx cancers, esophical cancer, liver cancer, breast cancer and colorectal cancer (2). Some evidence shows alcohol to have positive health benefits, such as red wine and the lowered risk of heart disease, but the negative results vastly outweigh the positive. Athletes and their high demand on nutrients due to their active lifestyle and the physical demands on training may be at more of a risk to nutritional deficiencies than those who don't exercise regularly. Alcohol is also calorically dense, yet not providing any large benefit of nutrients. Without proper tracking calories can quickly add up.

​

​

General Health Affects on Alcohol

​

​

BAC and Affect on Organs

Ethanol Alcohol is toxic to the brain, liver, heart, and pancreas. Over time and consumption deterioration of these organs is common. Over consumption can accelerate this deterioration, as well as bring fourth other issues. When talking about over consumption symptoms can be categorized by the individuals blood alcohol content (BAC). Listed below are symptoms for an average individuals BAC percentage (7):

0.033-0.12 percent​ BAC: improvement of mood, higher self-confidence, less anxiety, flushing of the face, shorter attention span, lack of fine motor coordination and impairment of judgement.

0.09-0.25 percent BAC: sedation, loss of memory and lack of comprehension, delayed motor reactions, balanced problems and ataxia, blurred vision and sensation impairment.

0.25-0.40 percent BAC: in and out of consciousness or complete unconsciousness, amnesia during events while intoxicated, staggering gait, vomiting with aspiration, respiratory depression, incontinence of urine and slowed heart rate.

0.35-0.80 percent BAC: comatose, lack of pupillary response to light, life-threatening respiratory depression, severe decrease in heart rate and potential death.

Damage done by alcohol internally is mostly unnoticed until damage is irreparable in later years. Long-term effects of chronic drinking include: cardiovascular disease, liver diseases, respiratory infections, cancer, nerve damage, and ulcers. Nutritional deficiencies can impact the health of all organs, potentially increasing the risk of alcohol induced conditions.

​

Brain

The brain feels the effects of alcohol quite quickly, effecting our brain causing loss of memory and motor skills, but long term effects can be experienced as well with continuing use of alcohol. Long term consumption of alcohol can hinder the brains function and structure, effecting the cerebellum, cerebral cortex, and limbic system (hippocampus, amygdala, hypothalamus), further disrupting communication in the brain.

​

Heart

The heart can be weakened with alcohol consumption, largely influencing the delivery of nutrients and oxygen to organs in the body. Alcohol consumption can also increase blood triglyceride levels in the body. Triglycerides are a type of fat composed of glycerol and three fatty acids. High levels of triglycerides in the body can lead to conditions such as heart disease and diabetes. As alcohol consumption leads to acute reactions such as high blood pressure and irregular heartbeats, long-term drinking and the raising of blood pressure can lead to conditions such as cardiomyopathy, arrhythmia, high blood pressure, stroke and cardiac death (2).

​

Liver

Reactions of the liver on alcohol can be quite drastic as alcohol is hepatotoxic - destructive to liver cells. The liver aids in the process of nutrients from solids and liquids and filters out the harmful substances in the blood. The liver also plays a role to break down and removal alcohol from the blood. Liver diseases that have been linked to alcohol consumption include steatosis, acute alcoholic hepatitis, cirrhosis, and hepatocellular carcinoma (1). The higher chances of developing these diseases are in direct correlation to intensity and frequency of consumed alcohol. 

 

Hepatic steatosis is a result from excessive amounts of alcohol which overload the liver and overtime can cause a build up of fats inside the liver. This can lead to the swelling of the liver (8). Hepatic Steatosis is more commonly known as fatty liver. When fatty liver develops from excessive alcohol consumption, it is classified as alcoholic fatty liver disease (AFLD). Fatty Liver influences metabolism and energy storage. The fatty change in the liver can be caused from obesity and diabetes, but certain features such as swelled hepatocytes, mallory bodies, and giant mitochondria are unique to alcoholic fatty liver disease (1). Individuals who regularly consume alcohol will have fatty build up in their livers, but the condition of AFLD is irreversible when pericentral venous fibrosis has developed (1).

 

Acute alcoholic hepatitis is an inflammatory reaction around an enlarged hepatocytes and in portal tracts. Acute alcoholic hepatitis involves death of liver cells, leading to permanent scarring (8). The average case of acute alcoholic hepatitis is reversible with a halt in alcohol consumption, but left untreated this condition can be a prerequisite to cirrhosis (1).

 

Alcohol cirrhosis usually becomes present in the body with chronic alcohol abuse. Alcohol cirrhosis includes the damaging and destruction of normal liver cells, leaving scar tissue where normal functioning liver tissue used to be (8). Individuals with cirrhosis are more at risk for developing kidney issues, intestinal bleeding, and liver cancer. Hepatocellular Carcinoma is a liver tumour which develops in 15-30% of patients with alcoholic cirrhosis (1).

​

Pancreas

The pancreas helps regulate blood sugar levels in the body. Effects of alcohol on the pancreas in the early stages are not easily noticeable until they become severe. Alcohol abuse can lead to pancreatitis and the swelling of blood vessels around the pancreas, increasing the chance of pancreatic cancer and preventing proper digestion (2). In western societies, heavy alcohol consumption is the cause for acute and chronic pancreatitis (1). 

​

​

Alcohol and Metabolism

Metabolism of alcohol is determined by two factors: genetic factors such as variations in alcohol breaking-down enzymes, and environmental factors including amount of alcohol consumed and overall nutrition and lifestyle of the individual (14). Alcohol is commonly metabolized by two enzymes: alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). ADH first metabolized the consumed alcohol into acetaldehyde (14). Acetaldehyde is highly toxic as well as a carcinogen - a specific chemical or agent that has the ability to cause cancer when an individual is exposed to it (15). Acetaldehyde is classified as a carcinogen due to its interference in DNA replication, and inhibiting DNA repairing processes (14). Acetaldehyde is then metabolized further into acetate, a less active byproduct, later to be turned into carbon dioxide and water to be eliminated from the body (14). Another enzyme catalase also contributes to the breakdown of a small amount ethanol into acetaldehyde. If lots of alcohol is consumed at once, the enzymes cytochrome P450 2E1 contributes as well to the breakdown alcohol into acetaldehyde.

​

Although the highly toxic acetaldehyde is only in the body for a short period of time before being broken down further into acetate, acetaldehyde has potential to do damage in the brain, pancreas, gastrointestinal tract, and especially in the liver where most of alcohol metabolism occurs. Some research implies that acetaldehyde is the reason to some acute psychological/behavioural effects when alcohol is ingested. A paper written by Etienne Quertemont, PhD. and Vincent Didone describes the results of lab animals being administered acetaldehyde, showing results of incoordination, memory impairment, and sleepiness (14, 16). Other scientists disagree with this statement as brain acetaldehyde concentrations are not high enough to produce these effects due to the blood-brain barrier protecting the brain from toxins in the bloodstream (14). 

​

Amount of alcohol metabolized depends on many personal factors including the individuals body mass and liver size. Individuals can carry different variations of ADH and ALDH enzymes making alcohol metabolism unique in individuals, some may be able to metabolize alcohol easier and more efficient than others with different variations of the enzymes. Because of these variations in enzymes, one could have a efficient ADH enzyme, quickly turning ethanol alcohol into acetaldehyde, and an inefficient ALDH enzyme which takes more time to convert that toxic acetaldehyde into a less threatening metabolite. This outcome would result in a higher chance of acetaldehyde inflicting damage on the body, as it is in the body for a longer duration due to the less efficient ALDH enzyme variation.

​

The chances of someone becoming an alcoholic has connections to genetics and what variation of ADH and ALDH they hold. An individual who has acetaldehyde build up in their body will tend to drink less and have low chances of alcoholism. High levels of acetaldehyde develop symptoms including a rapid heart beat, nausea, and facial flushing, making drinking less pleasant than those who have low levels on acetaldehyde in their bodies (14). A fast ADH variation and a slow ALDH variation will result in high buildup of acetaldehyde in the body, resulting in less enjoyable drinking and lower chances of alcoholism. Although individuals with a fast ADH variation and a slow ALDH variation may be somewhat sheltered from alcoholism, that increase in acetaldehyde in their body still puts them at a larger risk of bodily damage and health risks.

 

Although there is a large impact on alcohols effects of drinking, impact of environmental factors and their experiences in life vary in individuals. 

​

Alcohols ability to contribute to the risk of certain cancers (previously listed) can be partially due to the presence of acetaldehyde, a carcinogen. Acetaldehyde is not the only carcinogenic substance that is produced through alcohol metabolism - when large amounts alcohol are present and cytochrome P450 2E1 contributes in the metabolism process, reactive oxygen species (ROS) are produced, which damage DNA and proteins as well as interact with other substances to create carcinogenic compounds (14).

​

​

Effects of Alcohol Directly Impacting Athletes

​

​

Alcohol and Endocrine System

The endocrine system is composed of several glands across the body that monitor and secrete hormones. Hormones are chemical messengers to manage functions in the body by sending chemical signals through your blood to organs. Hormones assist in many ways in the body to maintain proper function of all organs. Alcohol consumption can impact hormone releasing glands, either prematurely releasing or delaying the release of hormones, creating an imbalance in the body. Below is a list of glands and hormones and their function that are confirmed to be affected by alcohol consumption:

• The hypothalamus is a gland located in the brain which collects information from the nervous system to determine if other glands should release more hormones or hold back. The hypothalamus produces multiple hormones that control the pituitary gland. Regulates other glands, sleep-wake cycles, body temperature, and appetite. As the central nervous system is impaired when alcohol is consumed, the judgement of the hypothalamus is impaired along with its communications to other glands.

• The pituitary gland is a small gland located below the hypothalamus. Produces hormones that influence growth and reproduction and constructs hormones and control the thyroid gland, adrenal gland, ovaries, and testes. The pituitary gland receives signals from the hypothalamus. An impaired hypothalamus leads to impaired signals to the pituitary gland.

• Located in the middle of your brain, the pineal gland primarily controls sleep-wake cycles by releasing the hormone melatonin. Darkness activates the pineal gland to release more melatonin, inducing sleep.

• The thyroid gland is responsible for metabolism located in the front of your neck. Alcohol is known to destroy thyroid cells and blocking the activity and level of hormones it produces (25).

• The parathyroid gland consists of four glands in which secrete the hormone called parathyroid hormone (PTH) into the bloodstream. PTH, calcitonin, and vitamin-D derived hormones control calcium levels in the body, maintaining calcium excretion, absorption and distribution. Alcohol can interferer with these hormones with outcomes of calcium deficiencies affecting bone health, an increase in calcium excretion due to PTH deficiency, disruption in vitamin D metabolism, limiting dietary calcium absorption, inhibiting formation of bone/bone-forming cells, and issues with the heart, kidneys, bones and nervous system.. Alcohol can also disrupt reproductive hormones disrupting bone metabolism. These affects on alcohol can eventually lead to osteoporosis with chronic drinking.

• The adrenal gland includes two glands, each on top of their kidney. These two glands assist in metabolism, blood pressure, stress levels, and sexual development. The adrenal gland releases cortisol. Alcohol increases cortisol production when the individual is drinking as well as later in the night. Sort-term, cortisol can increase blood pressure, alertness and attention, but with chronic high levels of cortisol can negatively impact bone growth, digestion, tissue repair and reproduction. High levels of cortisol can also disrupt muscle mass production.

• The pancreas contributes to the endocrine and digestive systems. It secretes the hormones insulin and glucagon, which function to regulate blood pressure and glucose levels in blood. Insulin works to lower glucose levels, where glucagon works to raise them. Hormones secreted from the adrenal gland and pituitary gland assist in the function of glucagon. Alcohol has been known to promote insulin secretion, putting the body into a hypoglycemic state, Inhibit glucose production during alcohol metabolism, and with heavy drinking, impair hormonal responses to hyperglycemia. Chronic drinking of alcohol can cause a glucose intolerance, increase glucagon, raising glucose levels, reduce the body's response to insulin, alter medication effects of diabetes, cause hypoglycemic and hyperglycemic states in alcoholics, and lower survival rates for alcoholics who also have diabetes (4).

• Ovaries in women release hormones estrogen, progesterone, and testosterone. Testes in males release testosterone. Alcohol can impair adequate functioning of testes and ovaries, developing hypogonadism, leading to hormonal deficiencies, sexual dysfunction, and infertility.

​

One hormone that has large impact on the body is testosterone. Alcohol limits testosterone secretion as well as boosting estrogen levels, leading to many different effects on the body. These side effects include a decrease sense in well being, depressed mood, moodiness, difficulty in concentration and memory, low sex drive, general fatigue and loss in muscle mass and strength (20) by limiting muscle protein synthesis. Studies have shown that alcohols impact on testosterone is greater in males than in females (21)

​

In women, alcohol consumption has the potential to affect hormones estrogen and progesterone. Drinking alcohol can increase estrogen levels, resulting in bloating, headaches, mood-swings, decreased sex drive, tenderness and swelling in breasts, and low sex drive (21, 22) While alcohol increases estrogen levels it also decreases progesterone levels, leading to migraines, hot flashes, low sex drive, abdominal uterine bleeding, and making it difficult for a woman to become pregnant (21).

​

​

Alcohol and Digestion/Nutrient Uptake

​

Alcohol interferes with the digestion and nutrient uptake process by influencing digestion, nutrient storage, nutrient utilization and excretion of nutrients (13). 

 

In regards to digestion, alcohol restricts the breakdown of nutrients by limiting pancreas secretion of digestive enzymes, damaging nutrient absorption cells lining the stomach and intestines, restricting nutrient transportation in blood, altering nutrient storage, and modifying nutrient excretion (13). Alcohol also has influence on our microbiome - the genetic material of microbes (bacteria, fungi, protozoa, and viruses) inside the body (13). Our microbiome helps digest food, regulate our immune system, protect agains harmful bacteria, and produce vitamins (12). Alcohol puts stress on the stomach and intestines, resulting in a decrease in digestion secretions and movement of food in the digestive tract (1). A lowered level of secretion results in lower levels of food being broken down into micro and macro nutrients.

​

Alcohol can impair nutrient uptake by restricting vitamin absorption, metabolism and utilization. Alcohol can affect vitamins A, B, C, D, E, and K. As alcohol impairs the utilization of these vitamins, many negative impacts occur as a result including: 

• Diminished defence against illness and infection (vitamin A/B1/B2/B3/B12/E deficiencies)

• Poorer vision in low levels of light (vitamin A deficiency) 

• Decrease health in skin and other tissue lining the body (vitamin A/B2/B3/C/E deficiencies)

• Decrease protection and health of cells (vitamin C deficiency)

• Decrease in blood vessel, bone and cartilage health (vitamin C/D deficiencies)

• Lower health in teeth and muscles (vitamin D deficiency)

• Diminished wound healing (vitamin C/K deficiencies)

• Diminished eye health (vitamin B2/E deficiencies)

• Blood clotting abnormalities (vitamin K deficiency)

• Impaired breakdown and retention of energy from food (vitamin B1/B2/B3/Pantothenic Acid deficiencies)

• Lower release levels of energy from food (vitamin B12 deficiency)

• Decrease in energy use storage from proteins and carbohydrates (vitamin B6 deficiency)

• Lower levels of hemoglobin in blood resulting in lower levels of oxygen transportation (vitamin B6 deficiency)

• Decrease fatty acid production (vitamin B7 deficiency)

• Decrease formation of health red blood cells (folate, vitamin B12 deficiencies)

• Increased risk of birth defects (folate deficiency)

• Decreased use of folate (vitamin B12 deficiency)

Chronic drinking can severely affect these deficiencies and other problems can emerge, such as scurvy from vitamin C deficiency, osteomalacia from vitamin D deficiency, osteoporosis from calcium deficiency, and anemia from B vitamins.

​

One mineral that is greatly impacted by alcohol consumption is calcium. Regular calcium levels are very important for proper heart, kidneys bone and nervous system function. Alcohol inhibits the parathyroid hormone (PTH) which has a large impact on calcium, disrupting calcium regulation in the body which can lead to disruption in bone health, bone-forming cells and the health of the heart, kidneys, and nervous system.

​

B vitamins are involved in the release of energy from carbohydrates, fats and proteins. A deficiency in B vitamins from a night out of drinking will result in less energy released in the morning. As mentioned above vitamin D and calcium are at risk for deficiencies with chronic alcohol consumption, one of calcium's and vitamin D's functions are to maintain muscle mass and lower risk of injuries when in proper levels in the body.

​

​

Alcohol and Sleep

Alcohol effects sleep patterns by disrupting the body's REM cycles. During sleep there are two phases you enter,  non-rapid eye movement sleeping (non-REM) followed by rapid eye movement (REM) sleep.

 

Non-REM sleep consists of three phases. Phase one is when the body begins to relax but it is still easy to wake you up. Phase two is where your heart rate slows and your temperature drops. Lastly, phase three is where deep sleeping begins. Body repairs and growth begin to take action here, as well as strengthening of the immune system. The non-REM cycle lasts for around 90 minutes, followed by a REM cycle which continues for 10 minutes before returning back to non-REM cycle. Each cycle REM sleep time lengthens (24).

​

REM sleep includes and increase in heart rate and breathing, as well as an increase in brain activity and repairing and growth of the body. REM stimulates areas of the brain where learning is involved. REM sleep cycles also contribute to the increase in protein production (24).

​

Alcohols disruption of REM cycles leads to less protein production as well as less repairing and growth of the body overnight in athletes. Nights of drinking have the potential to result in a disrupted sleep schedule as well.

​

Alcohols effect on sleep can also lead to hormone imbalances, and hormone imbalances can affect sleep. As discussed above, alcohol can affect testosterone levels. Lower testosterone levels can affect quality of sleep. Alcohol's affect on sleep has the potential to affect hormones controlling hunger, satiety and storage of energy.

​

Alcohol and Hydration

Hydration is important for transportation, chemical reactions, lubricants and shock absorption, and temperature regulation. Beverages with an alcohol content greater than 4% act as a diuretic, increasing urine output, resulting in a delayed recovery from hydration if not properly handled. Alcohol acts as a diuretic by affecting the pituitary gland and at the hypothalamus, impairing their ability to properly release antidiuretic hormone (ADH) which indicates which functions to communicate with the body on when to retain water, and when to release water through urination (23).

 

If dehydration from alcohol is not properly counterbalanced with an increase in fluids low energy levels and a decrease in athletic performance are a possibility. One way alcohol impairs athletic performance is through electrolyte imbalances resulting from previous alcohol consumption.

​

Alcohol and Muscle Gain/Fat Loss

Alcohol effects the construction of muscle through impairing muscle protein synthesis (MPS). Muscle protein synthesis is the process of incorporating amino acids into skeletal muscle proteins, and is a highly important operation in the muscle growth and recovery process. Alcohol affects this due to the absorption of nutrients needed for MPS. Alcohol also displaces carbohydrate and protein intake. This protein intake displacement when in a post-workout state restricts optimal muscle protein synthesis, hindering muscle growth and repair.

 

As well as hindering muscle protein synthesis, higher quantities of alcohol implement a larger scale of protein breakdown compared to the nutritions scale of protein synthesis, resulting in more muscle being broken down than muscle being built. 

 

Consuming more protein before a night out will not decrease the effects of alcohol one muscle protein synthesis, or of alcohols affect on protein breakdown.

​

When talking about hormones that contribute to muscle gain it is important to take note of alcohol's affect on cortisol. 

The catabolic hormone cortisol is also affected with alcohol consumption. Alcohol increases cortisol production in the adrenal gland, lengthening the time cortisol levels are elevated. High levels of cortisol over extended periods of time can result in the loss of muscle mass (25). The hormone testosterone functions to increase muscle protein synthesis. As alcohol decreases secretion of testosterone, resulting muscle protein synthesis is limited even more.

​

In regards to fat loss alcohol has many ways in which it can haunt your journey to losing weight.

 

Alcohol is primarily burned as your source of energy before glucose and lipids resulting in glucose and lipids consumed during the day being converted into adipose tissue and fat. Excess amounts of alcohol can lead to a condition called alcoholic fatty liver (discussed above), alcoholic fatty liver affects carbohydrate and fat metabolism and storage, leading to difficulty in fat loss.

​

As previously mentioned, alcohol is calorically dense, with 7 calories per gram and 14 grams in a standard North American drink, calories can quickly add up. Not only does alcohol contain high counts of calories, but with the calories comes very little nutrients in alcohol. 

​​

The best alcoholic beverages for weight loss include vodka, whiskey, gin, tequila, and brandy (how does alc affect weight loss)d

​

​

Alcohol and Recovery

For effective recovery to take place muscle protein synthesis stimulation needs to occur, glycogen stores needs to be replenished, and fluid balance restored. As previously mentioned above, Protein Synthesis can be disrupted by alcohol in many ways (listed above). Alcohols influences on insulin and glucagon can put the body in a hypoglycaemic state, restricting glycogen stores from being replenished. Beverages with an alcohol percentage greater than 4% can delay hydration recovery due to the increase in urination.

​

Sleep is also need for recovery. Although alcohol may induce sleep, as mentioned earlier alcohol effects sleeps REM cycles, limiting repairing and growth of the body, as well as protein production during sleep, diminishing recovery in the night and potentially disturbing your sleep schedule in the future.

​

Alcohol use decreases immune system function. This increases depresses motor skills, puts the body at a higher risk of injury, and prolongs the recovery process.

​

Recovery from injury is also disrupted from alcohol consumption due to limitations to the inflammatory response. Anti-inflammatory molecules are increased in production and pro inflammatory molecules are decreased in production when ethanol alcohol is introduced into the body. Furthermore, alcohol acts as a vasodilator which can decrease soft tissue even more due to an increase in blood flow in the body and in the injured area, potentially increasing the severity of the injury and prolonging recovery time.

​

​

Conclusion

When looking at all aspects of alcohols affect on the body, the costs seem to vastly outweigh the benefits, but it is important to note that the difference in acute and chronic affects listed, and how genetics do play just as important of a role as environmental aspects for your health impact on alcohol consumption.

​

​

Sources​

1. Therapondos, BSc, MBChB, MRCP, Delahooke, BSc, MBChB, MRCP, Hayes, MD, Ph.D, FRCP, Science Direct, 1999, Health Affects of Alcohol and Alcoholism,  S0738081X99000218

2. National Institute of Alcohol Abuse and Alcoholism, 2021, Alcohol's Effects on the Body, https://www.niaaa.nih.gov/alcohols-effects-health/alcohols-effects-body

3. Struve, Granite Mountain Behavioural Healthcare, 2021, Alcohols Affect on Muscles, https://granitemountainbhc.com/blog/alcohol-effect-on-muscles/

4. ISSA, Does Alcohol Affect Muscle Growth?, https://www.issaonline.com/blog/index.cfm/2020/does-alcohol-affect-muscle-growth

5. Lockett, MS, Healthline, 2018, How Does Alcohol Affect Weight Loss? https://www.healthline.com/health/alcohol-and-weight-loss

6. Yerby, 2021, Alcohol Rehab Guide, 2021, Types of Alcohol,  https://www.alcoholrehabguide.org/alcohol/types/

7. Galbicsek, Alcohol Rehab Guide, 2021, Effects of Alcohol, https://www.alcoholrehabguide.org/alcohol/effects/
8. Johns Hopkins Medicine, 2021, Alcoholic Liver Disease, https://www.hopkinsmedicine.org/health/conditions-and-diseases/alcoholinduced-liver-disease

9. Haring et. al, 2009, Prediction of Metabolic Syndrome by Low Serum Testosterone Levels in Men 2027.full.pdf

10. Steiner JL, Crowell KT, Lang CH. Impact of Alcohol on Glycemic Control and Insulin Action. Biomolecules. 2015;5(4):2223–2246. doi:10.3390/biom5042223

11. Cains, S., Blomeley, C., Kollo, M. et al. Agrp neuron activity is required for alcohol-induced overeating. Nat Commun 8, 14014 (2017). https://doi.org/10.1038/ncomms14014

12. Hair, Sharpe, Centre for Ecogenetics & Environmental Health, 2021, Fast Facts About the Human Microbiome https://depts.washington.edu/ceeh/downloads/FF_Microbiome.pdf

13. Buddy T, John C. Umhau, MD, MPH, CPE, Verywellmind, 2020, Alcohol's Effect on Nutrition, https://www.verywellmind.com/alcohols-effect-on-nutrition-3863403 

14. National Institute of Alcohol Abuse and Alcoholism, 2007, Alcohol Metabolism: An Update, https://pubs.niaaa.nih.gov/publications/aa72/aa72.htm

15. National Human Genome Research Institute, 2021, Carcinogen, https://www.genome.gov/genetics-glossary/Carcinogen

16. Quertemont, PhD., Didone, 2006, Role of Acetaldehyde in Mediating the Pharmacological and Behavioural Effects of Alcohol, https://pubs.niaaa.nih.gov/publications/arh294/258-265.pdf

17. Cleveland Clinic, 2021, Endocrine System, https://my.clevelandclinic.org/health/articles/21201-endocrine-system

18. Seladi-Schulman, Ph.D., Healthline, 2019, Endocrine Sytem Overview, https://www.healthline.com/health/the-endocrine-system

19. Buddy T, John C. Umhau, MD, MPH, CPE, Verywellmind, 2020, How Alcohol Can Impair the Body's Hormone System, https://www.verywellmind.com/alcohol-and-hormones-66570

20. Cleveland Clininc, 2018, Low Testosterone (Male Hypogonadism), https://my.clevelandclinic.org/health/diseases/15603-low-testosterone-male-hypogonadism

21. Erickson, 2021, The Healthy, Drinking Just This Much Alcohol Can Seriously Mess With Your Hormones, https://www.thehealthy.com/addiction/drugs-alcohol/alcohol-consumption-mess-hormones/

22. Purohit, Wiley Online Library, 2006, Moderate Alcohol Consumption and Estrogen Levels in Postmenopausal Women: A review, https://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.1998.tb03694.x

23. Parkview Health, 2021, The True Hazards of A Hangover, https://www.parkview.com/community/dashboard/the-true-hazards-of-a-hangover

24. Felson, MD, WebMD, 2020, What are REM and Non-REM Sleep?, https://www.webmd.com/sleep-disorders/sleep-101

25. Ottinger, The Muscle Ph.D., 2021, Alcohol and Gains, alcohol-and-gains