Hi Lexi,
First of all, please note that I am a medical librarian, not a
physician, so everything I can tell you is only based on what I've
found, not on any sort of professional opinion or knowledge. My first
piece of advice is that you talk to your personal physcian before
starting any sort of weight loss plan, particularly one that involves
the use of supplements.
Pyruvate is a natural byproduct of sugar metabolism, so it is among
the hundreds of herbal and natural supplements that are not regulated
by the FDA. As a result, it has not had to go through the same sort
of testing that a "drug" does - which means both that it is cheaper
and possibly more dangerous.
The research I've found (citations to follow) indicate that pyruvate
does help increase human metabolism when consumed in high doses.
Increasing your metabolism means that you burn energy faster - which
means that, as long as you don't increase your caloric intake, you'll
burn fat reserves and lose weight. However, there seems to be little
evidence that low/"normal" doses of pyruvate have any effect on
metabolic rate.
This article has an excellent review of the research into the effects
of pyruvate on fat consumption in the body (pages 509-512).
Unfortunately, because of copyright restrictions I can't send you the
full text of the article, but I'll abstract out some quotations below:
Canadian Journal of Applied Physiology 2000 Dec;25(6):495-523.
Dietary fat intake, supplements, and weight loss.
Dyck DJ.
"Supplements such as pyruvate have been shown to be effective at high
dosages, but there is little mechanistic information to explain its
purported effect or data to indicate its effectiveness at lower
dosages.... None of these compounds have been tested for their
effectiveness or safety over prolonged periods of time." (from the
abstract)
The dosages used in the high-dose study ranged from 22-90g, with
amount of pyruvate varying from 15-35g. This study was on morbidly
obese, bedridden women restricted to a diet of 500-1000 calories/day.
In general, most doctors would say that the results are only
applicable to people in the same circumstances, not to merely
overweight people on an exercise plan. Over the course of three
weeks, the women taking the supplement only lost about 1-1.5 kgs than
those on placebo (a little less than 2-3lbs over 3 three weeks).
Further caution: the effect of the supplement was much less than the
effect of the caloric restriction alone. (p. 510)
"More recent studies have also examined the effects of lower dosages
of isolated pyruvate on weight loss... but the results have been
equivocal." (p. 510)
One of the problems with pyruvate is that researchers don't know how
it works, partly because it seems to get digested along with
everything else. Thus, "we have recently completed a study...
demonstrating that acute, modest dosages of pyruvate (7-25g) fail to
elevate blood pyruvate over a subsequent 4-hr period." The
implication is that, if it doesn't make it into your blood, it can't
do anything to your body. (p. 510)
In addition, injecting the supplement directly into a vein/artery
doesn't increase the amount of pyruvate in your muscle (p. 511)
Basically, the above authors conclude that to get any benefit out of
pyruvate supplements, current research indicates that you'll have to
take 20-40 standard supplement pills PER DAY (ouch!). The doses
available in the stores tend to be 0.5-1g each, well below the tested
threshold.
Stanko is often cited as a researcher into the effects of pyruvate.
He recently completed a study on 17 obese women that looked at their
body fat gain while taking pyruvate vs. placebo:
Int J Obes Relat Metab Disord. 1996 Oct;20(10):925-30.
Inhibition of regain in body weight and fat with addition of 3-carbon
compounds to the diet with hyperenergetic refeeding after weight
reduction.
Stanko RT, Arch JE.
"We conclude that 3-carbon compounds decrease weight gain and
reaccumulation of body fat, without decreasing body protein gain, in
obese subjects with hyperenergetic refeeding subsequent to weight
loss."
Please note that in this study and the one cited above the subjects
took a combination of pyruvate with dihydroxyacetone. It is unclear
whether the pyruvate by itself would have the same results.
There was a study in 1999 that looked at lower dosages of pyruvate,
but still higher ones than are sold in most stores:
Nutrition. 1999 May;15(5):337-40.
The effects of pyruvate supplementation on body composition in
overweight individuals.
Kalman D, Colker CM, Wilets I, Roufs JB, Antonio J.
"Thus, the ingestion of 6 g of pyruvate for 6 wk, in conjunction with
mild physical activity, resulted in a significant decrease in body
weight and fat mass."
This study was done on healthy but overweight men and women
(Caucasian) so would be better suited to translation to the general
population than the above ones.
The effects of pyruvate have been tested primarily in mice (because
it's generally considered a bad thing to test this type of thing in
people until its been shown okay in mice). It looks like most of the
studies found that the drug had some effect on liver fats (good) and
can interact with certain metabolic disorders (bad).
This study showed that pyruvate by itself did not impair memory, but
when combined with GABA it did:
Neurobiol Learn Mem. 2003 May;79(3):243-51.
Septal infusions of glucose or pyruvate, but not fructose, produce
avoidance deficits when co-infused with the GABA agonist muscimol.
Shah AA, Parent MB.
"However, co-infusions of all doses of glucose (16.5, 33, or 66 nmol)
or the glycolytic end product pyruvate with muscimol impaired
retention performance."
I chose to go look at the medical literature first (I went to
www.pubmed.gov, the US National Library of Medicine database of
literature), since it can be difficult to tell whether sites on the
web have been sponsored by supplement manufacturers (who tend to gloss
over things like dosage levels). I did a search for "weight loss
pyruvate" in Google and found a lot of supplement-manufacturer sites,
but the About.com page for pyruvate actually has a number of good
links. I'd suggest you look at:
Vital Nutrition.com
http://www.vital-nutrition.com/pyruvate.htm
Take this with a grain of pyruvate, please, as they are trying to sell
you the supplement. However, they do acknowledge that an upset
stomach is a possible side effect of the supplement. This article
leans heavily on Stanko's research on obese women.
Dr. Patrick J. Bird, Ph.D. (University of Florida): Pyruvate as a
Dietary Supplement
http://www.hhp.ufl.edu/keepingfit/ARTICLE/pyruvate.htm
This is a much more trustworthy source, as the author has no (obvious)
stake in whether you take the supplement or not. He also refers to
the "megadose" studies, and suggests that "buyer beware" is the best
attitude.
Dr. Weil.com
http://www.drweil.com/app/cda/drw_cda.html
If you do a search at this site for "pyruvate" you'll get several
articles - all of which discuss the supplement in an easy to read
fashion. In all of them he concludes that pyruvate is an overrated
product unlikely to produce real results given the dosage.
And finally:
The Facts About Fitness - Pyruvate
http://www.thefactsaboutfitness.com/articles/pyruvate.htm
This British site nicely condenses the above information with the help
of clear text and figures. As with the two sites from the doctors,
and the clinical trials, the site concludes that while there are some
possible effects, the cost and inconvenience of taking high doses are
significant drawbacks. This site also has a nice list of references
that you can use to follow up.
So, to answer your initial questions:
- Pyruvate at some doses is effective at helping with fat loss, but
those doses may need to be very high compared to the dosage in each
pill.
- The only major side effect seems to be upset stomach, including
gurgling, pain, and (as the British put it) "wind."
- Whether your plan is more effective with the use of supplements is a
hard one to answer. It will come down to dosage level, amount of
weight lost, average metabolism with and without the supplement, etc.
My advice, repeated from the beginning: confer with your doctor. I
have a feeling that he/she will tell you to do the diet and exercise
plan, and that your gut feeling about the supplement's effectiveness
is right.
I hope this helps you make your decision! Please let me know if
there's anything I can clarify for you. Just to reiterate, I first
did a search in the PubMed MEDLINE database (www.pubmed.gov) from the
US National Library of Medicine, for research articles, then a search
in Google (www.google.com) for online websites.
Yours, librariankt |
