Diet, Nutrition and SupplementationPost here for supplement reviews or nutritional advice. If you're trying to get "ripped abz" THIS is where you should be.
This was forwarded to me a while back from our college RD....it was on one of the nutrition listservs that she frequents.
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Experimental Biology 2005 (FASEB J) Late Breaking Abstracts #LB250: Poster
Session
A Randomized Double-Blind Clinical Pilot Trial Evaluating the Effect of
Protein Source when Combined with Resistance Training on Body Composition
and Sex Hormones in Adult Males.
Samantha Rubin, Douglas Kalman, Michele Martinez, Diane R. Krieger,
Nutrition, Miami Research Associates, 6280 Sunset Drive, Suite 600, Miami,
Florida 33143.
Anecdotal evidence suggests that soy protein may alter serum hormone
concentrations of male athletes. The purpose of this pilot RDBT was to
compare the effect of supplementation of 50g per day of 4 different protein
supplements in combination with resistance training on body composition
(DEXA) and sex hormones in males. For 12 weeks, the subjects ingested
protein shakes (soy protein concentrate (SPC), soy protein isolate (SPI), a
soy + whey blend (50/50 mixture of SPI with whey protein concentrate [WPI]),
or whey (50/50 mixture of WPC and WPI)] 2x daily and participated in 3
hypertrophy-oriented training sessions per week. Intent-to-Treat analysis
(ITT: n=41) and Per Protocol Analysis (PP: n=20) revealed a significant
increase in lean body mass independent of protein type (0.5±1.1 and 0.9±1.4
kg, p=0.006, p=0.007 respectively).
No significant differences occurred between groups for changes in percent
body fat, lean body mass, body weight, total or free testosterone,
estradiol, SHBG or the T:E ratio. Within groups, ITT and PP analyses
revealed a significant increase in the T:E ratio for soy+whey (7.4±11 and
16.3±11, p=0.05, p=0.03 respectively; uncorrected for multiple comparisons)
and a significant estradiol decrease for whey (-6.4±8.4 and -9.1±8.7 pg/dl,
p=0.039, p=0.033 respectively; uncorrected for multiple comparisons). There
were no serious AE’s reported and no significant differences in AE rates
among groups. Compliance with the protein supplement was ~94% without
variation across groups.
In conclusion, daily supplementation of soy, whey or soy+whey results in
similar increases in lean body mass and does not negatively affect
testosterone or estradiol levels in males engaged in a weight lifting
program.
I have often wondered whether soy protein isolate would have any of the supposed bad (or good, for that matter) effects attributed to soy. After all, if the protein has really been "isolated" aren't all of the other soy components more or less gone? (Isoflavones, I think?) So I'm wondering if a study like this would really be evidence one way or the other about the effects of eating tofu or other less "isolated" soy products.
Well, I probably get about 1/2 of all my protein from soy sources (around 75-100 grams of soy protein each day since 1989)......so I hope I don't turn into a woman anytime soon. [img]/images/graemlins/frown.gif[/img]The rest comes from other plant sources. I just think it's funny how so many people hear 'soy' and 'effective during menopause...' etc. and they automatically assume that they will be growing man-boobs and that their testosterone levels will drop faster than Monica Lewinsky behind a desk.
Can't forget that isoflavones bring a wealth of proven health benefits as well. In the long run, we need to be concerned with our health, not just how we look in the mirror.
Thanks for posting this Dos. I'm glad to see a scientific study on the issue, rather than something from a bodybuilding website.
Good point about watching out for our overall health, rather than just our body composition.
Now I won't feel guilty eating my edamame with dinner [img]/images/graemlins/wink.gif[/img]
I do wonder why there are so many conflicting studies on this issue. Take this one, for example, which seems to find the exact opposite of what the study above found:
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Dietary protein to support anabolism with resistance exercise in young men.
J Am Coll Nutr. 2005; 24(2):134S-139S (ISSN: 0731-5724)
Phillips SM; Hartman JW; Wilkinson SB
Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1 CANADA. phillis@mcmaster.ca
Resistance exercise is fundamentally anabolic and as such stimulates the process of skeletal muscle protein synthesis (MPS) in an absolute sense and relative to skeletal muscle protein breakdown (MPB). However, the net effect of resistance exercise is to shift net protein balance (NPB = MPS - MPB) to a more positive value; however, in the absence of feeding NPB remains negative. Feeding stimulates MPS to an extent where NPB becomes positive, for a transient time. When combined, resistance exercise and feeding synergistically interact to result in NPB being greater than with feeding alone. This feeding- and exercise-induced stimulation of NPB is what, albeit slowly, results in muscle hypertrophy. With this rudimentary knowledge we are now at the point where we can manipulate variables within the system to see what impact these interventions have on the processes of MPS, MPB, and NPB and ultimately and perhaps most importantly, muscle hypertrophy and strength. We used established models of skeletal muscle amino acid turnover to examine how protein source (milk versus soy) acutely affects the processes of MPS and MPB after resistance exercise. Our findings revealed that even when balanced quantities of total protein and energy are consumed that milk proteins are more effective in stimulating amino acid uptake and net protein deposition in skeletal muscle after resistance exercise than are hydrolyzed soy proteins. Importantly, the finding of increased amino acid uptake would be independent of the differences in amino acid composition of the two proteins. We propose that the improved net protein deposition with milk protein consumption is also not due to differences in amino acid composition, but is due to a different pattern of amino acid delivery associated with milk versus hydrolyzed soy proteins. If our acute findings are accurate then we hypothesized that chronically the greater net protein deposition associated with milk protein consumption post-resistance exercise would eventually lead to greater net protein accretion (i.e., muscle fiber hypertrophy), over a longer time period. In young men completing 12 weeks of resistance training (5d/wk) we observed a tendency (P = 0.11) for greater gains in whole body lean mass and whole as greater muscle fiber hypertrophy with consumption of milk. While strength gains were not different between the soy and milk-supplemented groups we would argue that the true significance of a greater increase in lean mass that we observed with milk consumption may be more important in groups of persons with lower initial lean mass and strength such as the elderly.
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Maybe the increased amino acid uptake they found with whey isn't enough to show real-world differences in body composition, at least in the 12-week period of the previous study.
Qestion, Johnka. The abstract you post identifies hydrolyzed soy protein as the soy based supplement, but simply says milk or milk proteins as the milk based supplement. Do you know what the composition of the milk supplement was, or was it just milk? And if it was a different supplement than the Whey used in the study posted by dos, could that account for the difference in outcome?
Don't the soy and dairy industries have very powerful lobbies?
I used to work for a non-profit dairy lobbying outfit in the midwest that joked about their mortal enemy: the soy industry.
Maybe an explanation for the wide variance in studies.
Though not a scientific observation by any means but up until 30 years ago or so Japanese received a good portion of their protein intake from soy, as meat and dairy were rare and expensive. Of course Japan also have a high life expectency rate and had no low birth rate problems.
As to whether or or not soy is a good source I'd say Dos offers living proof.
Yeah John, lots of mixed info. Some of the worse soy studies, however, have been funded by Dairy-related companies etc.
It's a tough call on the long term effects since most of these studies are pretty short. I think in general though that people underestimate the efficacy of plant-based proteins.
This vegan doesn't seem to have a problem with his muscle mass though [img]/images/graemlins/wink.gif[/img]
[img]http://rds.yahoo.com/S=9606288 3/K=silverback+gorilla/v=2/SID =w/l=IVI/;_ylt=A0Je5wu2ogxEpGQ ASdSjzbkF;_ylu=X3oDMTA4NDgyNWN 0BHNlYwNwcm9m/SIG=129ec2t6c/EX P=1141765174/*-http%3A//www.americazoo.com/ki ds/graphics/gorillas2.jpg[/img]
I think the health benefits of soy, however, are pretty established in the research.
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Don't the soy and dairy industries have very powerful lobbies?
I used to work for a non-profit dairy lobbying outfit in the midwest that joked about their mortal enemy: the soy industry.
Maybe an explanation for the wide variance in studies.
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Yes, that's what I always wonder about as well. It seems like the pro-Soy people say many of the exact same negative things about Dairy as pro-Dairy people say about Soy (impact on thyroid function, for example). It's hard to know what's rhetoric and what's real.
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Qestion, Johnka. The abstract you post identifies hydrolyzed soy protein as the soy based supplement, but simply says milk or milk proteins as the milk based supplement. Do you know what the composition of the milk supplement was, or was it just milk? And if it was a different supplement than the Whey used in the study posted by dos, could that account for the difference in outcome?
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I'm not sure exactly what the breakdown for milk proteins was, but it would have been some mixture of casein and whey. So the two studies seem somewhat comparable.
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Yeah John, lots of mixed info. Some of the worse soy studies, however, have been funded by Dairy-related companies etc.
It's a tough call on the long term effects since most of these studies are pretty short. I think in general though that people underestimate the efficacy of plant-based proteins.
This vegan doesn't seem to have a problem with his muscle mass though [img]/images/graemlins/wink.gif[/img]
[img]http://rds.yahoo.com/S=9606288 3/K=silverback+gorilla/v=2/SID =w/l=IVI/;_ylt=A0Je5wu2ogxEpGQ ASdSjzbkF;_ylu=X3oDMTA4NDgyNWN 0BHNlYwNwcm9m/SIG=129ec2t6c/EX P=1141765174/*-http%3A//www.americazoo.com/ki ds/graphics/gorillas2.jpg[/img]
I think the health benefits of soy, however, are pretty established in the research.
LOL, that last ape's facial expression looks like Gollum.
But imagine how huge that ape would be if he drank shakes made of hydrolized whey and maltodextrin at a 1:2 ratio [img]/images/graemlins/tongue.gif[/img]
You bring up a very good point (also Kuri and BamaDave) - results can certainly be 'tweaked' when companies are throwing wads of cash into the studies. Researchers in this position are very unlikely to bite the hand that feeds them.
The Evil SOY!
Linear Mode
