What Are the Effects of Alcohol on Thiamin?

In affluent countries like the United States, up to 80 percent of alcoholics experience thiamin deficiency. Thiamin, or vitamin B1, is a nutrient found in whole grains, lean meats, legumes, fish and fortified grain products. Alcohol interrupts thiamin absorption and utilization, and the resulting deficiency affects the cardiovascular and nervous systems, causing brain damage in extreme cases.

Thiamin in the Body

• Whole grains are a natural source of thiamin.

  In the human body, thiamin supports the functions of the heart, muscles and nervous system. It also supports the metabolism, helping the body produce energy from carbohydrates. For most people, the body's thiamin needs can be met by eating a balanced diet, but when the body can't absorb enough thiamin, or can't use it properly due to chronic alcohol consumption, the results include weakness, fatigue, nerve damage and even psychosis.

Alcohol and Thiamin

• Alcohol disrupts the body's thiamin supply in several different ways. First, alcoholism can result in lessened dietary thiamin intake. Even when enough thiamin is ingested, alcoholics can't absorb most of it, because alcohol prevents the thiamin that is ingested from being effectively absorbed in the gastrointestinal tract, or from being effectively used on the cellular level. The resulting deficiency affects the brain and heart, and causes sodium and water retention in the blood. In some people, chronic alcohol-induced thiamin deficiency leads to serious health problems, such as dementia or heart failure.

Korsakoff Syndrome

• Wernicke's encephalopathy and Korsakoff syndrome involve alcohol-related brain damage.

  Korsakoff syndrome and Wernicke's encephalopathy are two types of brain damage caused by alcohol-related thiamin deficiency, and are thought to be two stages of the same disease. Wernicke's encephalopathy causes confusion, lack of muscle coordination and vision changes. Wernicke's encephalopathy is a short-lived condition, but when it passes, the symptoms of Korsakoff syndrome tend to appear. Korsakoff syndrome manifests as an inability to form new memories, and can result in severe memory loss. Increased thiamin intake can slow or stop the damage involved in Wernicke's encephalopathy and Korsakoff syndrome, but cannot reverse the brain damage that has already occurred.

Beriberi

• Wet beriberi affects the cardiovascular system.

  Beriberi is another disease that can occur when alcoholism results in a thiamin deficiency, and it has two distinct forms. Wet beriberi causes shortness of breath, increased heart rate and swollen lower legs by interfering with the cardiovascular system's normal functioning. Dry beriberi affects the nervous system, resulting in confusion, loss of sensation in the extremities, pain or tingling, vomiting and loss of muscle function. Beriberi is deadly when left untreated, but the damage can be reversed with timely medical intervention.