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Skidmore College
Health Services

Alcohol and Nutrition

Alcohol. A complicated substance with a wide continuum of use and influence on the individual user. From a simple social-outing cocktail to a life destroyed by the obvious or insidious effects of excessive drinking or alcoholism, how one uses or abuses alcohol may be determined by genetics, the amount consumed and the general health of the individual. The choice to drink alcohol is usually dependent on external considerations without much thought given to internal implications. But, to give our bodies the respect they deserve, let's consider what is going on in the body when we choose to drink.

The Effects of Alcohol on the Body

Alcohol is classified as a depressant though it may act as a stimulant or a depressant depending on the dose. Exhilaration, talkativeness, loss of inhibitions, extreme mood swings, and displays of excessive emotion all mark the stimulant phase. All occur at lower doses.

The initial stimulant effects are due to a release of hormones from the adrenal glands as alcohol stimulates the adrenals as it is absorbed from the intestines. Alcohol does not directly act on the brain in low doses. 20% of the alcohol consumed can be directly absorbed through the walls of the stomach. Alcohol dehydrogenase is the major enzyme responsible for breaking down ethanol. One reason women tend to get intoxicated more quickly is that they produce less alcohol dehydrogenase in the stomach than men. A stomach full of food will also slow down the absorption process of alcohol. As the amount of ingested alcohol increases it will cross the blood brain barrier.

After it reaches the duodenum, alcohol is rapidly transported to the liver via the blood vessels of the digestive system. Once there, it spreads through the hepatic blood vessels to cover as much area of the liver as possible. Alcohol is mainly metabolized by the alcohol dehydrogenase system (ADS) in the liver—being oxidized to acetaldehyde.

Alcohol receives preferential treatment in the liver and is metabolized while other nutrients must wait. Fatty acids that would normally be metabolized by the liver must wait until the alcohol is fully processed. In heavy drinkers, this leads to a fatty liver and other serious liver disorders.

In the second step of metabolism, acetaldehyde is converted to acetic acid by the enzyme aldehyde dehydrogenase. Under normal circumstances, acetaldehyde is metabolized rapidly and does not accumulate or interfere with normal functioning. However, when large amounts of alcohol are consumed, accumulation of acetaldehyde causes headache, gastritis, nausea and dizziness--hangovers. Clearly, there is a threshold of tolerated use.

Countable calories

Alcohol supplies 7 kilocalories per gram and comes from a carbohydrate source. Yet, it is not used like a carbohydrate for fuel in the body. Instead it is metabolized like a fat. Individuals partaking in frequent or excessive social drinking are at risk of increased weight gain due to the additional calories from the alcohol and the snack food accompaniments.

In cases of heavy drinking and alcoholism, when the amount of alcohol surpasses the abilities of the ADS, ethanol is metabolized into acetaldehyde by the microsomal ethanol oxidizing system (MEOS). While alcohol has 7 kilocalories per gram when it is metabolized by the ADS, when the MEOS kicks in, this is not the case. The ADS produces adenosine triphosphate (ATP) while the MEOS burns ATP to function. It is difficult to predict how many calories will be produced when an individual slips into the MEOS. If the individual with alcoholism does not eat, he or she will become malnourished despite drinking many alcohol calories per day.

To fully and efficiently metabolize alcohol down to its benign components the process requires adequate thiamin, niacin, riboflavin, zinc, and manganese. An undernourished individual will have a harder time detoxifying the alcohol in their system and be more vulnerable to its effects.

Alcohol may interfere with the absorption of the B vitamins, especially folic acid and thiamin. Malnutrition causes high levels of acetic acid to remain in and circulate through the body. The body of a person with alcoholism changes to accommodate the extra acetic acid and gradually develops more mitochondria in the liver and muscles. This is a physical adaptation and the person will experience physical cravings and withdrawals when he or she tries to stop drinking.

Nutritional Effects

Individuals with drinking problems suffer from nutritional attacks on two fronts—consequences of using alcohol and its effects on the body and mind; and consequences of the lifestyle; i.e. deficient dietary intake and haphazard eating habits. Poor dietary intake and the substitution of alcohol for food is a leading cause of malnutrition in individuals with alcoholism. Metabolism and brain chemistry changes in people over time with repeat alcohol abuse.

Adverse Effects of Overindulgence of Alcohol

  • Increased Tolerance and Craving
  • Physical Dependence
  • Serious liver disorders
  • Pancreatitis
  • Wernicke-Korskoff Syndrome due to thiamine deficiency
  • Inflammation and Irritation of the Stomach Lining
  • Decreased absorption of many nutrients
  • Hypoglycemia
  • Elevated Triglycerides
  • High blood pressure
  • Stroke
  • Heart failure
  • Cancer
  • Injuries, domestic violence, disrupted lives and relationships, and death.

Nutrition for Recovery

People with alcoholism appear deficient in most nutrients but have a special need for niacin, zinc, thiamin, B-6, Vitamin C, magnesium, Vit K and calcium replenishment. Vit A can be toxic to an individual with poor liver function. However, deficiencies of Vit A may be present as well and therefore should be provided through a food source. Vit A supplements taken with alcohol can be extremely toxic. Vit B-12 may be low due to gastric disturbances from drinking, especially if the individual suffers from gastritis. Postmenopausal women with alcoholism are at higher risk of osteoporosis. Addictions cannot be eradicated until the underlying nutritional deficiencies are also addressed.

Source: Alcohol Abuse and Dependence: Nutrition on the Rocks. Mary Anne Clairmont, RD. Today's Dietitian, September 2005.