Two studies on slimming supplement calcium pyruvate
According to a 1998 study, paid for by a supplements manufacturer that had launched calcium pyruvate [structural formula shown below], this substance is an excellent slimming supplement. A study done in 2005, however, comes to a different conclusion.
Pyruvate is a ketone and an alpha-keto acid. It is formed in the body when glucose is transformed into energy. Pyruvate plays a role in the Krebs cycle, the complex reaction in which nutrients are converted into energy.
Extremely high doses of pyruvate stimulate the breakdown of fat in the body. In 1998, researchers working for the manufacturer New Vision International looked at whether the calcium salt of pyruvate also worked at a 'low' dose of 6 grams. [Nutrition. 1999 May; 15(5): 337-40.] And yes, it did.
The researchers gave the supplement for six weeks to 52 men and women in their mid-thirties with a body fat percentage of 21.
The test subjects did circuit training three times a week, and they trained their main muscle groups at high speed with 12 basic exercises, including lat pulldowns, leg press and chest press. The subjects consumed 2000 kcal per day.
The fat mass in the calcium pyruvate group decreased by 12 percent, and their lean body mass increased by 2 percent.
Nice results. Less nice though, are the results of the 2005 study. It's not clear who financed this study.
The 86 female test subjects were fatter than those in the 1998 study. Their body fat percentage was around 35 percent. The women were given 5 g calcium pyruvate every day for 4 weeks. These test subjects also did circuit training 3 times a week. They did not go on a diet.
The figure below shows that calcium pyruvate did not have a significant effect on body composition. Black bars = pyruvate group; white bars = placebo group.
Calcium pyruvate raised the LDL level and lowered the HDL level. The effects weren't overwhelming, but they were statistically significant.
So there are two possibilities. Either the 1998 study is not correct, and calcium pyruvate doesn't work. Or both studies are right – and calcium pyruvate works better the lower your body fat percentage is to start with.
Nutrition. 2005 Mar; 21(3): 312-9.
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