How Does Pyruvate Work?

If you've been in the diet supplement market for a number of years, you've probably come across the names "pyruvate" and "pyruvic acid." Pyruvate is the form of pyruvic acid that is found in the human body. It is a three-carbon compound that is an important intermediate in biological energy production. While our body normally synthesizes it, we also get a small amount from our diet. Food sources for pyruvate include certain fruits and vegetables, as well as dark beer and red wine.

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Past research has shown that pyruvate can have beneficial effects at supraphysiological levels (that is, when the amount of pyruvate exceeds the minimum necessary for the body to function well). Indeed, in addition to acting as a biological fuel, pyruvate seems to increase endurance capacity, improve fat loss and exhibit antioxidant properties.

Mechanisms

The pyruvate that the body synthesizes is a product of glycolysis, the breakdown of glucose for energy production. When there's not enough oxygen in a tissue, pyruvate is converted into lactate. In the presence of oxygen, pyruvate is converted into acetyl coA, which enters the TCA cycle. The TCA cycle is a series of reactions that yield most of the energy necessary for the proper function of the human body. Pyruvate thus acts as a biological fuel.

Pyruvate supplementation also seems to improve endurance capacity. Since the body's energy needs are greater during physical exercise, the glucose stored in muscle glycogen is broken down whenever energy supply from the blood becomes low. Studies indicate that pyruvate increases the transport of glucose into muscle cells through a process called "blood glucose extraction." This spares muscle glycogen, and therefore helps preserve muscle mass.

A third potential benefit of pyruvate is that it improves body composition in obese individuals. Rat and human studies offer possible explanations of the way pyruvate induces fat loss. Rat studies indicate that, when pyruvate is combined with a compound called dihydroxyacetone, it lowers the respiratory quotient (RQ) of the organism. RQ is the ratio of carbon dioxide production to oxygen utilization in body cells. A lower RQ usually means that the organism is oxidizing, or "burning," more fat to produce energy. Fat oxidation is a process that requires oxygen. As a result, the resting metabolic rate is increased. Human studies seem to confirm the hypothesis that pyruvate supplementation can assist with fat loss by increasing the rate of fat oxidation.

Animal studies have also shown that pyruvate has antioxidant activity. Indeed, pyruvate neutralizes such potentially harmful oxygen species as hydrogen peroxide and lipid peroxides. More indirectly, pyruvate can augment the body's glutathione (GSH) antioxidant system. It does so by generating compounds that will keep the GSH in a reduced, and therefore more effective, form.

Caution

Because of potential toxicity, drug interactions, or other personal factors, you should always discuss diet supplementation with your doctor. This is also true of pyruvate, even though past studies have shown its potential applications to human health.

References

• Neurochemistry International journal; Antioxidant Effect of Ethyl Pyruvate in Respiring Neonatal Cerebrocortical Slices After H2O2 Stress; J. Liu et al.; February 2009; Volume 54(2)
• American Journal of Clinical Nutrition; Dietary Supplements for Body Weight Reduction: A Systematic Review; Max Pittler and Edzard Ernst; 2004; Volume 79 (4)
• Physician Desk Reference for Nutritional Supplements; 2001