Trimethylglycine, commonly called betaine, is a nutrient known as a methyl donor. Methyl donors carry and donate methyl molecules, which is important for cell reproduction and other chemical processes in the body, explains the University of Maryland Medical Center, or UMMC. Trimethylglycine occurs in beets, broccoli, spinach, grains and shellfish. Supplements also are available, derived from sugar beets. Consult a qualified health care provider before taking trimethylglycine supplements.
Trimethylglycine decreases high levels of the amino acid homocysteine that occurs naturally in the body, according to the UMMC. Levels of this substance can become elevated due to insufficient intake of certain nutrients, such as some B vitamins. A high level of this amino acid is a risk factor for heart disease and stroke, although no one has yet determined the exact effects of homocysteine, notes UMMC. Doctors sometimes test patients at risk of heart disease for elevated homocysteine levels and may recommend taking trimethylglycine supplements along with other nutrients.
A hereditary condition called homocystinuria causes homocysteine to accumulate in the blood in toxic levels. The condition is present at birth and involves an inability to break down the amino acid homocystine. Symptoms of homocystinuria may include excessive tiredness, eye lens dislocation, seizures, abnormal bone development, weak bones and blood clots. Children may have slowed development and a decreased rate of weight gain. People with homocystinuria are at much higher risk than the general population of developing cardiovascular disease, which can develop as early as their twenties. Doctors prescribe trimethylglycine to treat this condition, according to the U.S. National Institutes of Health at its MedlinePlus website.
Animal research indicates that trimethylglycine may have protective effects on the liver and could prevent fatty liver deposits, according to UMMC. Fatty liver can develop due to chronic alcohol use, insufficient protein intake, obesity and diabetes. A study published in the February 2009 issue of "Alcoholism: Clinical and Experimental Research" notes that alcohol use may induce fatty liver partly by increasing the activity of sterol regulatory element-binding protein-1, or SREBP-1. The study authors found that administering trimethylglycine to mice with alcohol-induced liver injury both inhibited SREBP-1 activity and improved the condition of fatty liver. Some studies with humans have also generated positive results, but UMMC cautions that this research has not always been of high quality.