What you are about to read is an updated version of what I originally wrote in 1996, which to my knowledge was the one of the first totally unbiased assessments of pyruvate, comparing each reported claim to what is known from the published peer reviewed scientific evidence, and written specifically for the everyday person who doesn't have the time to go rummaging through the scientific literature, as I did, looking for the answers.

     Pyruvate (also known as pyruvic acid) molecule is formed from the sugar glucose (blood sugar) during the process known as glycolysis (Powers and Howley, 1994) - which is one of the energy generating pathways that our bodies use every second of everyday to make ATP (adenosine triphosphate) - our "ultimate" energy molecule. Basically when you make energy in glycolysis, you start with the sugar glucose, run in through some metabolic steps, and end up with pyruvate (Stryer, 1988). ATP (or "energy") is formed during the process. Pyruvate also occurs naturally in food with fruits and vegetables containing the greatest amounts of pyruvate (McArdle, Katch & Katch, 1999). Red apples, for example, have some of the highest concentrations of pyruvate with 500 mg per apple (McArdle et. al. 1999). From what I have been able to gather, pyruvate was first employed as a means to prevent fatty build up in livers from chronic alcohol use (Goheen, Perason Larkin and Rao, 1981).

Pyruvate and Weight Loss

     Of the few studies available today which refer to pyruvate and weight loss, all of them say that it works. In one study (Stanko Tietze and Arch, 1992a), obese women (defined as being over 200 lbs.) using on a low calorie diet, plus pyruvate for 21 days lost 37% more weight and 48% more fat than obese women on a low calorie diet but not using pyruvate. This figure appears very impressive, I admit, but things look a little differently when you look at the actual pounds lost. In this particular study, the obese women using pyruvate lost an average of 12.98 pounds of body weight while the women not using the pyruvate lost an average of 9.46 pounds. That's an average difference of only 3.52 pounds between them! So the women using the pyruvate only lost about 3 ½ more pounds than those not using pyruvate. Now, let's look at how much fat was lost in this study. The obese women using pyruvate lost an average of 8.8 pounds of fat while those not using pyruvate lost an average of 5.6 pounds. This means that the women using pyruvate only lost about 3 pounds more than the other women not using it.
     In another study (Stanko, Tietze, Arch, 1992b), obese women (again over 200 lbs) on a low calorie diet plus pyruvate lost an average of 14.3 pounds while those only on the low calorie diet lost 12.3 pounds. This comes out to only about a 2 pound difference. As for the fat loss, the women on the pyruvate lost an average of 9.5 pounds while those not using the pyruvate lost an average of 7.7 pounds. This means that the group using the pyruvate lost only about 1.5 pounds more fat that those not using pyruvate! You should also know that the fat loss may not be 100% accurate in these studies because body fat loss was determined with bioelectrical impedance analysis and not the "gold standard" of underwater weighing, which is used in most scientific studies. It is also important to note that thus far no published peer reviewed weight loss studies using pyruvate have been conducted in men, as far as I can determine. Therefore, it is difficult to know for certain if the same weight loss effect observed in women would be also observed in men.

Pyruvate and Metabolism

Pyruvate and Cholesterol Levels

     With respect to pyruvate altering one's cholesterol levels, the evidence seems to indicate that pyruvate does not result in any significant alterations in total cholesterol, HDL (good cholesterol), LDL (bad cholesterol) or triglycerides (fats) (Stanko; 1992a; Stanko, 1994).

Pyruvate and the Inhibition of Regaining of Weight

     Now, let's talk about how pyruvate seems to inhibit the regaining of weight after it has been lost. From all the scientific studies that I have been able to find, this claim seems to be based on only one study (Stanko, 1996). In this investigation obese women (average weight 228 pounds) went on a low calorie diet for 3 weeks and then went on a 3 day high calorie diet to purposely regain the weight. Some women used pyruvate during the dieting process. In those women who did not receive pyruvate, an average of about 6.4 pounds of weight was regained. In those women who received pyruvate, an average of about 4 pounds of body weight was regained. This amounts to only a 2.4 pounds difference between the group taking the pyruvate and the group who didn't use the pyruvate. There was not a very big difference between the groups. When you look at how much body fat was regained in these women, we see a similar picture. Women not using pyruvate regained an average of about 4 pounds of fat while those using the pyruvate regained an average of about 1.7 pounds of fat. This amounts to only about 2.3 pounds difference between them.

Pyruvate and the Suppression of Appetite

     One published peer reviewed study (Cortez, 1991) has reported that pyruvate seemed to suppress the appetite - in laboratory rats - when they were allowed to eat as much as they wanted. To date, no published peer reviewed study that I was able to uncover has investigated this phenomenon in humans so it is unknown it these results can be extrapolated to people. This is unfortunate for it represents a vast untapped area of pyruvate research.

     Thus far, pyruvate supplementation use seems relatively safe with short term use. For side effects expected with pyruvate use, most studies report occasional diarrhea, loose or softened stools and a rumbling sound in the gut which is caused by gas passing through the intestines. One subject in one of the pyruvate studies reported dizziness, but this seems isolated and thus far has never been observed in any other subject participating in any other pyruvate study. Studies also indicate that pyruvate does not seem to effect heart rate, body temperature, or blood pressure (Stanko, 1992b). Results may vary with other populations such as men, adolescents, seniors or people who have existing medical problems.

     Currently, it is thought that supplemental pyruvate enhances muscular endurance by increasing the transport of glucose into the cells where it can be used for energy (McArdle et. al. 1999). How pyruvate supplementation augments weight and fat loss remains a mystery (McArdle, et. al. 1999).

Marketing Claims for Pyruvate

* Pyruvate is backed up by 25 years of extensive scientific research (Roufs, 1996). While it's true, I did find actual peer reviewed scientific studies in prestigious scientific journals, when I jumped onto the internet and looked at medline, one of the world's most extensive collection of published medical and scientific information, I was unable to find any study on pyruvate and how it relates to actual weight loss published before 1986 or after 1996.

* Some people selling pyruvate - as well as other dietary supplements - give out free audio tapes which boast of pyruvate's supposed amazing abilities. In one of these tapes which I have heard, the person selling pyruvate states that when you are using pyruvate, that you are in the fat burning mode - even when you are not exercising. It is important to note that you are ALREADY in the fat burning mode when you are not exercising! At rest, approximately 70% of the calories you derive energy from are coming from fat with the remaining 30% coming from carbohydrates (Baechle, 1994).

* Some make the claim that pyruvate aids with cardiac function. There seems to be little proof of this claim. In fact those studies that did keep a record pyruvate's effect on heart functions, found no change after use (Stanko, 1992a; Stanko, 1992b).

* There seems to be no published peer reviewed scientific evidence which finds that pyruvate can build muscle tissue.

My Thoughts

Upon reviewing the above mentioned pyruvate studies, I would like to clarify the picture a bit with the following points:

A. Unlike the vast majority of weight loss gimmicks out there today, pyruvate has actual, peer reviewed scientific studies, published in respected scientific journals, to back up many of its claims. This fact alone puts pyruvate ahead of 99.9% of all the other weight loss gimmicks and products out there today. I would be remiss however if I did not point out that these very studies show that pyruvate is far from the magic weight loss bullet that some would make it out to be.

B. To date, most weight loss studies except seem to have been done on either rats or obese women on low calorie diets. No published scientific study to date seems to have investigated how pyruvate works in non-obese people eating a normal diet. Therefore, results in men and women who are not considered "obese" and/or who are not on a low calorie diet may-and probably will - differ from the results obtained from the studies done thus far.

C. Thus far, the vast majority of published peer reviewed studies on pyruvate have been done by Professor Ronald Stanko,who is a respected researcher, at the University of Pittsburgh.

D. Dieting seems paramount for anyone, if you wish to see optimum results with pyruvate. Just like anything out there, it's unlikely that anybody is going to lose weight if you take pyruvate with a milkshake! The American College of Sports Medicine (ACSM) recommends that if you are going to diet, that you do not go below 1200 calories a day (ACSM position statement, 1983).

E. According to the December 1996 issue of Muscle and Fitness as well as by the pyruvate distributors I have spoken with, the optimum dose for use is between 3-5 grams a day. It is interesting though that no published peer reviewed study that I can find used this amount. In fact, most of the studies used much more than this - sometimes up to 75 grams a day! I am unaware of any published peer reviewed study showing how the 3-5 gram dose was ever identified or any published peer reviewed study showing that this 3-5 gram per day dose is effective in weight loss.

F. Some of the pyruvate studies used Sodium Pyruvate. If you are considering using pyruvate and have high blood pressure you might want to switch to a sodium free brand. To be on the safe side however, if you are on any medications or have any medical problem whatsoever, I STRONGLY advise that you talk to your physician first before you begin using pyruvate, or any other weight loss product.

G. Pyruvate seems to be immediately absorbed when taken. Also, since other studies mixed pyruvate with food, it seems logical that you do not have to take it on an empty stomach.

H. At the present time no published peer reviewed study that I can locate has investigated how pyruvate -induced weight loss works in athletes so any claim that it works in athletes is seems presumptuous. Bottom Line: it is difficult determine how something will work in trained athletes using data obtained from studies that used obese women and laboratory rats. In addition, no published peer reviewed study has looked at the interaction between pyruvate-induced weight loss and exercise. This would seem a prudent area for future research.

I. No one is sure of the long term side effects associated with constant pyruvate use. While with the exception of a few minor problems, pyruvate seems to be safe for short term use. It seems that no published peer reviewed study that I could uncover has ever lasted more than 1 month. This raises long term safety use questions in my opinion.

The studies on pyruvate to date are interesting in that they show the pyruvate seems to have some biological effect on fat breakdown and an increased weight loss. However I would like to stress that all of the claims made about pyruvate are based on only a few studies, and in some instances, it seems only 1 study. More investigations are needed before a definitive final verdict can be given on pyruvate.