Alcoholism contributes to malnutrition by decreasing appetite and vital nutrients; drinking often serves as a substitute for meals, according to MayoClinic.com. Many alcoholics become malnourished either because they consume too few essential nutrients or because alcohol and its metabolism prevent the body from using those nutrients, according to the National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health. Alcoholism results in maldigestion and malabsorption of nutrients.
Moderate drinkers usually consume alcohol in addition to their normal food intake, and its contribution to body fat is most evident in the central obesity commonly referred to as “beer belly.” Alcohol in heavy doses is not well metabolized and generates more heat than fat. Heavy drinkers usually consume alcohol instead of normal food intake and tend to suffer malnutrition, according to Eleanor Whitney and Sharon Rolfes in “Understanding Nutrition.”
Compared to 4 calories per gram for protein and carbohydrate, alcohol contains 7 calories per gram but these empty calories are devoid of nutrients. A 12 oz. serving of regular beer provides 150 calories. A 1 ½ oz. serving of 80 proof liquor provides 100 calories and a 3 ½ oz. serving of white wine provides 70 calories. Generally, the more calories spent on alcohol, the fewer calories spent on nutritious food.
The more alcohol people drink, the less likely they are to consume enough food to provide adequate nutrition. Nutrient deficiencies are inevitable, according to “Understanding Nutrition,” because alcohol displaces food and interferes with the body’s use of nutrients. Eventually, certain nutrients are either missing or ineffective.
Chronic alcoholism interferes with the metabolism of nutrients consumed. As an example, according to “Understanding Nutrition,” the liver loses its ability to retain the B vitamin folate so the kidneys excrete more folate in the urine and a folate deficiency that devastates the digestive system develops.
Alcohol also interferes with folate’s role in processing homocystine, so an excess level that is linked to heart disease develops. Poor folate status and alcoholism are also linked to colorectal cancer. Impairment and deficiency of another B vitamin, thiamin, results in Wernicke-Korsakoff syndrome, which affects the eye muscle, damaged nerves, impaired memory and coordination.
Acetaldehyde, produced by alcohol metabolism, also causes a vitamin B-6 deficiency which results in lower production of red blood cells.
Alcohol contributes to malnutrition by interfering with the effective use of some vitamins. For instance, intestinal cells fail to absorb thiamin, folate and vitamin B-12. Liver cells lose the ability to effectively activate vitamin D, according to “Understanding Nutrition.”
Direct toxic effects of alcoholism contribute to malnutrition. Alcohol causes stomach cells to secrete too much gastric acid and histamine. Histamine produces inflammation and too much gastric acid irritates the stomach and esophagus linings and makes them vulnerable to the formation of ulcers.