Pyruvate: the return
A little bit long but interesting.....
Boosting Exercise Performance with Pyruvate and Dihydroxyacetone
by Edmund R. Burke, Ph.D.
Many athletes are forever searching for nutritional magic bullets to boost their performances. Sometimes the remedies turn out to be mere fads and, like baseball caps worn backward, don't have much practical purpose. Recently, pyruvate, a stabilized form of pyruvic acid, and its sister compound, dihydroxyacetone, have become popular dietary supplements in sports nutrition (together they are referred to as DHAP). Fortunately, use of these nutrients is backed by scientific evidence showing that they augment muscle glycogen, fat loss and exercise endurance.
The Dynamic Duo
Pyruvic acid results from the body's metabolism of glucose and amino acids, where glucose (a six-carbon molecule) yields two molecules of pyruvic acid (a three-carbon molecule). Pyruvic acid is chemically unstable and can cause nausea and intestinal discomfort. So, for supplemental forms, manufacturers stabilize it by forming a "salt" called pyruvate. Pyruvate salts are formed when pyruvic acid is combined with either sodium, calcium, potassium or magnesium. The salts are easily broken back down into individual components when ingested. Manufacturing pyruvates isn't a simple process, which is one of the primary reasons these substances are only now entering the marketplace.
Dihydroxyacetone is a product of the metabolism of glucose and glycerol. In the body, a series of enzymatic steps rapidly converts dihydroxyacetone to pyruvate. For this reason, more recent studies have used supplemental pyruvate alone, rather than both dihydroxyacetone and pyruvate.
DHAP supplements improve athletic endurance by enhancing "glucose extraction" or the amount of glucose that muscle cells can take from the circulating blood. When exercised, muscle cells can then burn the glucose for energy; at rest, they can store it as glycogen.
When athletes engage in intense daily training, muscle-glycogen stores undergo daily depletion and resynthesis. The amount and type of dietary carbohydrate intake influences muscle-glycogen synthesis. An investigation by David Costill, Ph.D., director of the Human Performance Laboratory at Ball State University in Muncie, Ind., assigned trained runners to three dietary regimens that varied in carbohydrate content. Group one consumed 25 percent (188 g) of their total 3,000 kilocalories as carbohydrate; group two 50 percent (375 g); and group three 70 percent (525 g). To measure glycogen content, researchers took muscle biopsies from the gastrocnemius (the largest muscle in the calf) immediately after exercise, and again 24 hours later. The results demonstrated that during the 24-hour period muscle-glycogen synthesis increased in proportion to the amount of carbohydrate consumed.1 Costill recommends that athletes whose daily training relies heavily on muscle-glycogen reserves (i.e., swimmers, runners and cyclers) take at least 70 percent of their calories from carbohydrates.2
An Alternate Fuel
In the past, experts advised that athletes eat their carbohydrates in complex form, stoking up on foods such as brown rice, whole-grain breads and pastas. Then in the early 1980s, glucose polymer drinks (long chains of sugar molecules that stay connected in solution) were marketed as a way to replace glycogen stores without the added bulk of whole grains in the intestinal tract. More recent research has shown that dihydroxyacetone and pyruvate increase muscle-glycogen stores more effectively than glucose polymers.
Two double-blind studies of 18 volunteers conducted by Ronald Stanko, M.D., and colleagues at the University of Pittsburgh Medical Center in Pa., showed that seven days of DHAP supplementation to athletes on both normal and high-carbohydrate diets significantly improved arm and leg exercise performance compared to a carbohydrate placebo. Muscular endurance in both the arms and legs rose by 20 percent.3,4
These results are supported by a third double-blind study that assigned eight subjects to one of two dietary combinations. Both diets contained 15 percent protein, 30 percent fat and 55 percent carbohydrate; the treatment diet substituted 75 g of DHAP for some of the carbohydrate. While cycling at the same workloads, subjects taking DHAP reported a more than 20-percent decrease in perceived level of exertion.5
Researchers believe that DHAP improves exercise performance primarily by enhancing glucose extraction and by increasing glycogen stores. DHAP supplementation can increase glucose extraction by 150 percent while arm cycling, and by 60 percent while leg cycling.6,7 DHAP also enhances glucose extraction at rest, leading to a 50 percent increase in muscle glycogen stores.8
Researchers have yet to determine the optimal pyruvate allowance. Total daily intake ranges from 100 mg to 1-2 g. Although pyruvate is found in a variety of foods, most contain less than 25 mg per serving. Foods high in pyruvate include certain fruits, vegetables, wines and cheeses. A red apple packs 450 mg, 12 ounces of beer contains 80 mg, and 6 ounces of red wine has 75 mg.
For athletes to get the full benefits of pyruvate, they usually need to take supplements. Many of the products on the market contain primarily pyruvate; some contain small amounts of dihydroxyacetone. Pyruvate is available in tablet, capsule and powder form. It also appears in drinks and energy bars.
Early studies used 100 g of DHAP as a mixture of 25 g pyruvate and 75 g dihydroxyacetone. Later, researchers realized that lower doses were just as effective. Stanko says the optimal dosage is 2-5 g a day of pyruvate, divided into two doses and taken with meals.9
Side Effects And Cautions
No major side effects have been associated with pyruvate or DHAP. In one study, side effects associated with large doses of pyruvate (18-24 g) were gas and bloating (placebo equals 46 percent of subjects, pyruvate 65 percent); loose stool (placebo 12 percent, pyruvate 24 percent); and diarrhea (placebo 0 percent and pyruvate 35 percent).10
One Westlake, Calif.-based pyruvate manufacturer notes that, because the quality of raw pyruvate has increased tremendously, the intestinal side effects documented in early studies are no longer common. According to Terry Newsom, director of marketing for the company, "pyruvate is not only effective but [as shown in Dr. Stanko's research] has no serious side effects."
Since it has many metabolic effects, pyruvate supplementation is not recommended for pregnant women or children, unless monitored by a physician. Other people should consult with a health practitioner before taking any supplement in pharmacological doses. As with all supplements or medications, unexpected side effects should be reported to a physician.
Research needs to be done on the effects of various dosages and forms of pyruvate on male and female athletes. For doses exceeding 5 g per day, we need to know the effect that minerals chelated with pyruvate have on the body's mineral and electrolyte balance.
In addition, more studies are needed to investigate the full range of pyruvate's benefits. Because it has been shown to increase fat loss,11 pyruvate may benefit people with obesity, diabetes and hyperlipidemia (high blood fats such as triglycerides and cholesterol).12 Preliminary research also suggests that pyruvate may improve cardiac efficiency by increasing glucose extraction.13 I suspect we are only beginning to discover the positive influence of pyruvate and dihydroxyacetone on health.
Sidebars:
Benefits of Pyruvate
References
1. Costill, D.L., Bowers, R., et al. "Muscle glycogen utilization during prolonged exercise on successive days." J Appl Physiol, 31: 834-38, 1971.
2. Costill, D.L., Sherman, W.M., et al. "The role of dietary carbohydrate in muscle glycogen synthesis after strenuous running." Am J Clin Nutr, 34: 1831-36, 1981.
3. Stanko, R.T., Robertson, R.J., Spina, R.J., et al. "Enhancement of arm exercise endurance capacity with dihydroxyacetone and pyruvate." J Appl Physiol, 68: 119-24, 1990.
4. Stanko, R.T., Robertson, R.J., Galbreath, R.W., et al. "Enhanced leg exercise endurance with a high carbohydrate diet and dihydroxyacetone and pyruvate." J Appl Physiol, 69: 1651-56, 1990.
5. Robertson, R.J., Stanko, R.T., Goss, F.L., et al. "Blood glucose extraction as a mediator of perceived exertion during prolonged exercise." Eur J Appl Physiol, 61: 100-5, 1990.
6. Stanko, R.T., Robertson, R.J., Spina, R.J., loc. cit.
7. Stanko, R.T., Robertson, R.J., Galbreath, R.W., loc. cit.
8. Stanko, R.T., Robertson, R.J., Spina, R.J., loc. cit.
9. Burke, E.R. Pyruvate: 40. New Canaan, C.T: Keats Publishing, 1997.
10. Stanko, R.T., Reiss Reynolds, H., et al. "Pyruvate supplementation of a low-cholesterol, low-fat diet: Effects on plasma lipid concentrations and body composition in hyperlipidemic patients." Am J Clin Nutr, 59: 423-27, 1994.
11. Stanko, R.T., Reiss Reynolds, H., ibid.
12. Stanko, R.T., Mitrakou, A., et al. "Effect of dihydroxyacetone and pyruvate on plasma glucose concentration and turnover in noninsulin-dependent diabetes mellitus." Clin Physiol Biochem, S: 283-88, 1990.
13. U.S. Patent 5,294,641. Method for Treating a Medical Patient for Cardiac Trauma.
A little bit long but interesting.....
Boosting Exercise Performance with Pyruvate and Dihydroxyacetone
by Edmund R. Burke, Ph.D.
Many athletes are forever searching for nutritional magic bullets to boost their performances. Sometimes the remedies turn out to be mere fads and, like baseball caps worn backward, don't have much practical purpose. Recently, pyruvate, a stabilized form of pyruvic acid, and its sister compound, dihydroxyacetone, have become popular dietary supplements in sports nutrition (together they are referred to as DHAP). Fortunately, use of these nutrients is backed by scientific evidence showing that they augment muscle glycogen, fat loss and exercise endurance.
The Dynamic Duo
Pyruvic acid results from the body's metabolism of glucose and amino acids, where glucose (a six-carbon molecule) yields two molecules of pyruvic acid (a three-carbon molecule). Pyruvic acid is chemically unstable and can cause nausea and intestinal discomfort. So, for supplemental forms, manufacturers stabilize it by forming a "salt" called pyruvate. Pyruvate salts are formed when pyruvic acid is combined with either sodium, calcium, potassium or magnesium. The salts are easily broken back down into individual components when ingested. Manufacturing pyruvates isn't a simple process, which is one of the primary reasons these substances are only now entering the marketplace.
Dihydroxyacetone is a product of the metabolism of glucose and glycerol. In the body, a series of enzymatic steps rapidly converts dihydroxyacetone to pyruvate. For this reason, more recent studies have used supplemental pyruvate alone, rather than both dihydroxyacetone and pyruvate.
DHAP supplements improve athletic endurance by enhancing "glucose extraction" or the amount of glucose that muscle cells can take from the circulating blood. When exercised, muscle cells can then burn the glucose for energy; at rest, they can store it as glycogen.
When athletes engage in intense daily training, muscle-glycogen stores undergo daily depletion and resynthesis. The amount and type of dietary carbohydrate intake influences muscle-glycogen synthesis. An investigation by David Costill, Ph.D., director of the Human Performance Laboratory at Ball State University in Muncie, Ind., assigned trained runners to three dietary regimens that varied in carbohydrate content. Group one consumed 25 percent (188 g) of their total 3,000 kilocalories as carbohydrate; group two 50 percent (375 g); and group three 70 percent (525 g). To measure glycogen content, researchers took muscle biopsies from the gastrocnemius (the largest muscle in the calf) immediately after exercise, and again 24 hours later. The results demonstrated that during the 24-hour period muscle-glycogen synthesis increased in proportion to the amount of carbohydrate consumed.1 Costill recommends that athletes whose daily training relies heavily on muscle-glycogen reserves (i.e., swimmers, runners and cyclers) take at least 70 percent of their calories from carbohydrates.2
An Alternate Fuel
In the past, experts advised that athletes eat their carbohydrates in complex form, stoking up on foods such as brown rice, whole-grain breads and pastas. Then in the early 1980s, glucose polymer drinks (long chains of sugar molecules that stay connected in solution) were marketed as a way to replace glycogen stores without the added bulk of whole grains in the intestinal tract. More recent research has shown that dihydroxyacetone and pyruvate increase muscle-glycogen stores more effectively than glucose polymers.
Two double-blind studies of 18 volunteers conducted by Ronald Stanko, M.D., and colleagues at the University of Pittsburgh Medical Center in Pa., showed that seven days of DHAP supplementation to athletes on both normal and high-carbohydrate diets significantly improved arm and leg exercise performance compared to a carbohydrate placebo. Muscular endurance in both the arms and legs rose by 20 percent.3,4
These results are supported by a third double-blind study that assigned eight subjects to one of two dietary combinations. Both diets contained 15 percent protein, 30 percent fat and 55 percent carbohydrate; the treatment diet substituted 75 g of DHAP for some of the carbohydrate. While cycling at the same workloads, subjects taking DHAP reported a more than 20-percent decrease in perceived level of exertion.5
Researchers believe that DHAP improves exercise performance primarily by enhancing glucose extraction and by increasing glycogen stores. DHAP supplementation can increase glucose extraction by 150 percent while arm cycling, and by 60 percent while leg cycling.6,7 DHAP also enhances glucose extraction at rest, leading to a 50 percent increase in muscle glycogen stores.8
Researchers have yet to determine the optimal pyruvate allowance. Total daily intake ranges from 100 mg to 1-2 g. Although pyruvate is found in a variety of foods, most contain less than 25 mg per serving. Foods high in pyruvate include certain fruits, vegetables, wines and cheeses. A red apple packs 450 mg, 12 ounces of beer contains 80 mg, and 6 ounces of red wine has 75 mg.
For athletes to get the full benefits of pyruvate, they usually need to take supplements. Many of the products on the market contain primarily pyruvate; some contain small amounts of dihydroxyacetone. Pyruvate is available in tablet, capsule and powder form. It also appears in drinks and energy bars.
Early studies used 100 g of DHAP as a mixture of 25 g pyruvate and 75 g dihydroxyacetone. Later, researchers realized that lower doses were just as effective. Stanko says the optimal dosage is 2-5 g a day of pyruvate, divided into two doses and taken with meals.9
Side Effects And Cautions
No major side effects have been associated with pyruvate or DHAP. In one study, side effects associated with large doses of pyruvate (18-24 g) were gas and bloating (placebo equals 46 percent of subjects, pyruvate 65 percent); loose stool (placebo 12 percent, pyruvate 24 percent); and diarrhea (placebo 0 percent and pyruvate 35 percent).10
One Westlake, Calif.-based pyruvate manufacturer notes that, because the quality of raw pyruvate has increased tremendously, the intestinal side effects documented in early studies are no longer common. According to Terry Newsom, director of marketing for the company, "pyruvate is not only effective but [as shown in Dr. Stanko's research] has no serious side effects."
Since it has many metabolic effects, pyruvate supplementation is not recommended for pregnant women or children, unless monitored by a physician. Other people should consult with a health practitioner before taking any supplement in pharmacological doses. As with all supplements or medications, unexpected side effects should be reported to a physician.
Research needs to be done on the effects of various dosages and forms of pyruvate on male and female athletes. For doses exceeding 5 g per day, we need to know the effect that minerals chelated with pyruvate have on the body's mineral and electrolyte balance.
In addition, more studies are needed to investigate the full range of pyruvate's benefits. Because it has been shown to increase fat loss,11 pyruvate may benefit people with obesity, diabetes and hyperlipidemia (high blood fats such as triglycerides and cholesterol).12 Preliminary research also suggests that pyruvate may improve cardiac efficiency by increasing glucose extraction.13 I suspect we are only beginning to discover the positive influence of pyruvate and dihydroxyacetone on health.
Sidebars:
Benefits of Pyruvate
References
1. Costill, D.L., Bowers, R., et al. "Muscle glycogen utilization during prolonged exercise on successive days." J Appl Physiol, 31: 834-38, 1971.
2. Costill, D.L., Sherman, W.M., et al. "The role of dietary carbohydrate in muscle glycogen synthesis after strenuous running." Am J Clin Nutr, 34: 1831-36, 1981.
3. Stanko, R.T., Robertson, R.J., Spina, R.J., et al. "Enhancement of arm exercise endurance capacity with dihydroxyacetone and pyruvate." J Appl Physiol, 68: 119-24, 1990.
4. Stanko, R.T., Robertson, R.J., Galbreath, R.W., et al. "Enhanced leg exercise endurance with a high carbohydrate diet and dihydroxyacetone and pyruvate." J Appl Physiol, 69: 1651-56, 1990.
5. Robertson, R.J., Stanko, R.T., Goss, F.L., et al. "Blood glucose extraction as a mediator of perceived exertion during prolonged exercise." Eur J Appl Physiol, 61: 100-5, 1990.
6. Stanko, R.T., Robertson, R.J., Spina, R.J., loc. cit.
7. Stanko, R.T., Robertson, R.J., Galbreath, R.W., loc. cit.
8. Stanko, R.T., Robertson, R.J., Spina, R.J., loc. cit.
9. Burke, E.R. Pyruvate: 40. New Canaan, C.T: Keats Publishing, 1997.
10. Stanko, R.T., Reiss Reynolds, H., et al. "Pyruvate supplementation of a low-cholesterol, low-fat diet: Effects on plasma lipid concentrations and body composition in hyperlipidemic patients." Am J Clin Nutr, 59: 423-27, 1994.
11. Stanko, R.T., Reiss Reynolds, H., ibid.
12. Stanko, R.T., Mitrakou, A., et al. "Effect of dihydroxyacetone and pyruvate on plasma glucose concentration and turnover in noninsulin-dependent diabetes mellitus." Clin Physiol Biochem, S: 283-88, 1990.
13. U.S. Patent 5,294,641. Method for Treating a Medical Patient for Cardiac Trauma.