Gains in performance? Itís not from the nitrates
By: Anthony Roberts
Betaine, a nutrient found in beetroot juice, has recently been found to be an ergogenic (performance enhancing) compound. A 2008 study performed at UCONN found that betaine supplementation plus carbohydrate supported increases of both aerobic and anaerobic metabolism compared to carbohydrate alone, while a 2010 study at TCNJ observed that two-weeks of betainesupplementation in active, college males appeared to improve muscle endurance of the squat exercise, and increase the quality of repetitions performed. A follow-up study from UCONN, in 2010, concluded that betaine supplementation increases power, force and maintenance for certain selected performance measures.
However, these gains are unlikely to have anything to do with nitrate levels. A recently published study from the University of Memphis found that betaine supplementation does not increase the plasma level of nitrate. This means, all other things being equal, the gains in performance from betaine, which had previously been attributed to the high nitrate level of betaine, are unlikely to have been caused through this mechanism of action (*at least according to this study).
So if youíve been telling people that you made great gains from nitrates because youíve been using a betaine supplement, it may be time to rethink that claim.
Effect of betaine supplementation on plasma nitrate/nitrite in exercise-trained men
Betaine, beetroot juice, and supplemental nitrate have recently been reported to improve certain aspects of exercise performance, which may be mechanistically linked to increased nitric oxide. The purpose of the present study was to investigate the effect of betaine supplementation on plasma nitrate/nitrite, a surrogate marker or nitric oxide, in exercise-trained men.
We used three different study designs (acute intake of betaine at 1.25 and 5.00 grams, chronic intake of betaine at 2.5 grams per day for 14 days, and chronic [6 grams of betaine per day for 7 days] followed by acute intake [6 grams]), all involving exercise-trained men, to investigate the effects of orally ingested betaine on plasma nitrate/nitrite. Blood samples were collected before and at 30, 60, 90, and 120 min after ingestion of 1.25 and 5.00 grams of betaine (Study 1); before and after 14 days of betaine supplementation at a dosage of 2.5 grams (Study 2); and before and after 7 days of betaine supplementation at a dosage of 6 grams, followed by acute ingestion of 6 grams and blood measures at 30 and 60 min post ingestion (Study 3).
In Study 1, nitrate/nitrite was relatively unaffected and no statistically significant interaction (p = 0.99), dosage (p = 0.69), or time (p = 0.91) effects were noted. Similar findings were noted in Study 2, with no statistically significant interaction (p = 0.57), condition (p = 0.98), or pre/post intervention (p = 0.17) effects noted for nitrate/nitrite. In Study 3, no statistically significant changes were noted in nitrate/nitrite between collection times (p = 0.97).
Our data indicate that acute or chronic ingestion of betaine by healthy, exercise-trained men does not impact plasma nitrate/nitrite. These findings suggest that other mechanisms aside from increasing circulating nitric oxide are likely responsible for any performance enhancing effect of betaine supplementation.