When you think of long term detrimental impacts of alcohol consumption, malnutrition may not come to mind immediately. In reality, this is a much larger problem than most people may perceive.
Alcohol and Energy
Just as lipids, protein and carbohydrates provide a set amount of calories for each gram consumed, so does alcohol. When consuming alcohol in various beverages, we actually obtain 7 calories for each gram of alcohol in addition to the calories from carbohydrates found in many alcoholic beverages. When we consume alcohol containing beverages, we are increasing our calorie intake without gaining any valuable macronutrients or micronutrients. This becomes increasingly problematic with the more alcohol we consume as large doses of alcohol suppress a person’s appetite.
Competition for Nutrients
In addition to the decreased amount of beneficial nutrients being consumed by an individual, the body also uses precious micronutrient resources to metabolize alcohol, limiting their availability for metabolizing the nutrients our body actually requires. This produces competition for different vitamins including the water soluble B vitamins. Our liver requires various B vitamins to break down and metabolize alcohol for excretion. When our body has large amounts of alcohol it is responsible to rid itself of, there is less vitamin B available for essential body processes such as converting food into energy.
Vitamins
Due to decreased intake and increased excretion, vitamin deficiency is a common problem faced by chronic consumers of alcohol. With every deficiency comes an increased risk of adverse clinical manifestations.
Effect on Small Intestines
The small intestines play a critical role in digestion. In the small intestines, almost all of the digestion and absorption of nutrients occurs. Over time, alcohol consumption severely impacts the structure of the small intestine and therefore their function.
One of the changes observed within the small intestines is a change in motility. Usually, the small intestines are stimulated by the enteric nervous system to send waves of motion in response to undigested food. These waves allow for food to be moved along and digested. Alcohol inhibits the ability of the enteric nervous system to sense undigested food and consequently leads to decreased waves. Decreased motion through the small intestines prevents digestive enzymes from mixing with food leading to decreased digestion of nutrients. The issue is compounded by deceased time of nutrients spent circling the villi where they are typically absorbed. As a result of these factors, individuals may experience diarrhea.
The other major impact on the small intestines is the change in structure. Normally, the small intestine is covered in tiny projections, villi, which increase the surface area for absorption. Over time, moderate alcohol drinkers will experience shortening villi consequently decreasing surface area available for absorption. In chronic drinkers, villi become so short that they are reduced to nubs which often bleed. Once this blood is introduced into the abdominal cavity, the digestive system triggers a rapid, violent clearance of contents through vomiting.