Dimethylglycine (DMG) and its Effects on Body
Thursday, April 16th, 2009N, N, dimethylglycine (DMG) was discovered in 1943 and marketed under the name pangamic acid or vitamin B15. This substance was touted as a cure for various ailments such as cancer and glaucoma. Since then, it is the belief that supplementation with DMG could increase performance. Marketers of DMG have made various claims such as an increased use of oxygen and increased mental alertness with the use of DMG. A review of DMG has shown an increase in tissue oxygen uptake and increased exercise performance however, most of these studies were highly criticized.
Animal Studies
In a crossover study by Rose et al., 1.2 mg/kg of DMG or a placebo paste were orally administered to six thoroughbred horses (body weight = 424-492 kg) twice per day for 5 days. The horses exercised at 40-50% for 2 minutes followed by 1 minute of exercise at 60, 70, 80, 90, and 100%. carbon dioxide production, heart rate, arterial blood and plasma lactate concentration, arterial blood gases, and pH were measured during the last 5 seconds of each stage. Also, muscle biopsy specimens were taken from the middle gluteal muscle before and immediately after exercise to determine muscle lactate concentrations. The results showed no significant differences between the groups for any of the parameters measured.
Human Studies
A study by Pipes was conducted using 12 male track athletes (18-21 years of age). The subjects received 5 mg of pangamic acid or a placebo for 1 week. Performance was measured by having the subjects run on a treadmill at a 7.5% grade and 9.0 mph. The speed was increased 1.5 mph every minute until exhaustion. The subjects receiving pangamic acid improved their running times significantly (23.6%) when compared with the placebo group (0.9%). There was also a significant increase in the treatment group (27.5%) when compared with the placebo (3.3%). Pangamic acid also significantly improved performance in a study by Kemp however, neither one of these studies involved subject or investigator blinding.
The effect of pangamic acid on treadmill performance was determined using 16 male track athletes. The athletes ingested six, 50-mg tablets per day of pangamic acid or a placebo for 3 weeks in this double-blind study. Before and after supplementation, the subjects performed a Bruce treadmill protocol to determine maximal heart rate, treadmill time, recovery heart rate (1 and 3 min), blood glucose levels, and lactate levels. The results showed no significant difference between groups for any of the parameters.
Black and Sucec also showed no improvement with the ingestion of DMG. They had 18 physically active men perform an inclined treadmill test after the ingestion of six 50-mg tablets of calcium pangamate (two per meal) or a placebo for 2 weeks. The results showed no significant improvement or 15-minute running performance time.
A study by Bishop et al. was conducted using trained runners. The results showed no significant improvement in ventilation, oxygen uptake, heart rate, or total run time when compared with a placebo. These results were similar to a study done by Girandola et al.
DMG has been proposed to increase oxygen use by skeletal muscle. This should lead to an increase in endurance performance. Regardless, DMG has not shown much potential as an endurance enhancement.
Safety and Toxicity
Studies have been conducted on the effects of DMG using rabbit models. When testing for the immunomodulating capacity of DMG, no toxic or adverse side effects occurred. Also, when DMG (300-600 mg/day) was administered to patients with epilepsy to control seizure frequency, no toxicity was noted.