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anyone use soy protein?
- Thread starter AAP
- Start date
justinjones1963
New member
AAP said:
MD recently had an article regarding this issue. Soy DOES effect estrogen levels but you would have to consume very large amounts of it (I can't remember how much but it was very significant).
I stick with whey but from what I have read a few dosages of soy protein per day will not effect estrogen levels.
CO B-man
New member
Here are a couple easy reads I just found seems it is not as bad as I thought. But now I am confused and do not know what is right/wrong. One thing for sure is that the shit tastes good!
http://www.wheyoflife.org/facts/Pro..."Protein source Biological value comparisons"
How does soy protein compare to whey protein?
Although soy protein does have its benefits, whey is a better protein for the athlete in regards to short term recovery. The two main reasons lie in whey’s fast absorption rates and its excellent biological value (BV). Whey is a higher quality protein than soy, containing a high volume of the key amino acids important for protein synthesis/growth, proper immune system function, and the body's production of glutathione, a powerful antioxidant in the body. Soy lacks these important amino acids in high volume. Combining these two attributes, when rapid absorption of amino acids is required immediately after exercise, whey is able to quickly provide these to the body via an excellent protein source.
http://www.wheyoflife.org/facts/Pro..."Protein source Biological value comparisons"
How does soy protein compare to whey protein?
Although soy protein does have its benefits, whey is a better protein for the athlete in regards to short term recovery. The two main reasons lie in whey’s fast absorption rates and its excellent biological value (BV). Whey is a higher quality protein than soy, containing a high volume of the key amino acids important for protein synthesis/growth, proper immune system function, and the body's production of glutathione, a powerful antioxidant in the body. Soy lacks these important amino acids in high volume. Combining these two attributes, when rapid absorption of amino acids is required immediately after exercise, whey is able to quickly provide these to the body via an excellent protein source.
Tux
Well-known member
I eat soy in the form of things like Cliff Bars which have 10g's of protein in them. I eat them as snacks between meals. Most of my protein comes from whey shakes and whole food though, and I notice no difference with 50-100g's of my protein coming from soy as opposed to whey.
truckdaddy
Banned
my buddy has a degree in nutrition.....he says it is shit.
ProtienFiend
New member
Just mix it in with other stuff. Id say if you had 1/4 of daily protein intake from soy you would have no negative effects. I have nothing to back that up, im just trying to say: Be diverse. Bodybuilders and such love to cling onto things and be to one extreme or the other (thats just how we are).
Im not a big shake person though as I feel whole foods are much better.
Im not a big shake person though as I feel whole foods are much better.
theprofessor
New member
amen to real food...ProtienFiend said:
but i dont think some soy here or there is going to hurt at all... i get a shake made with soy at the juice bar at the gym once in a while...
njmuscleguy
New member
It seems that smaller amounts of soy protein could be beneficial by aiding heart health (improving cholesterol, reducing hypertension), improved renal function, and for osteoarthritis.... however, some studies have shown that moderate to high levels of soy could affect test / DHT levels:
J Nutr. 2005 Mar;135(3):584-91.
Inverse associations between soy and prostate cancer and the contribution of hormones to prostate cancer prompted the current study to determine whether soy protein could alter serum hormones in men. Thirty-five men consumed milk protein isolate (MPI), low-isoflavone soy protein isolate (SPI) (low-iso SPI; 1.64 +/- 0.19 mg isoflavones/d), and high-iso SPI (61.7 +/- 7.35 mg isoflavones/d) for 57 d each in a randomized crossover design. Twenty-four-hour urine samples indicated that urinary isoflavones were significantly increased by the high-iso SPI relative to the low-iso SPI and MPI. Serum collected on d 1, 29, and 57 of each treatment revealed that dihydrotestosterone (DHT) and DHT/testosterone were significantly decreased by the low-iso SPI [9.4% and 9.0%, respectively] and the high-iso SPI [15% and 14%, respectively, compared with the MPI at d 57. Other significant effects included a decrease in testosterone by the low-iso SPI relative to the MPI (P = 0.023) and high-iso SPI at d 29; an increase in dehydroepiandrosterone sulfate by the low-iso SPI relative to the MPI at d 29 and relative to the MPI and high-iso SPI at d 57; and increases in estradiol and estrone by the low-iso SPI relative to the MPI at d 57. In conclusion, soy protein, regardless of isoflavone content, decreased DHT and DHT/testosterone with minor effects on other hormones, providing evidence for some effects of soy protein on hormones. The relevance of the magnitude of these effects to future prostate cancer risk requires further investigation.
J Nutr. 2005 Mar;135(3):584-91.
Inverse associations between soy and prostate cancer and the contribution of hormones to prostate cancer prompted the current study to determine whether soy protein could alter serum hormones in men. Thirty-five men consumed milk protein isolate (MPI), low-isoflavone soy protein isolate (SPI) (low-iso SPI; 1.64 +/- 0.19 mg isoflavones/d), and high-iso SPI (61.7 +/- 7.35 mg isoflavones/d) for 57 d each in a randomized crossover design. Twenty-four-hour urine samples indicated that urinary isoflavones were significantly increased by the high-iso SPI relative to the low-iso SPI and MPI. Serum collected on d 1, 29, and 57 of each treatment revealed that dihydrotestosterone (DHT) and DHT/testosterone were significantly decreased by the low-iso SPI [9.4% and 9.0%, respectively] and the high-iso SPI [15% and 14%, respectively, compared with the MPI at d 57. Other significant effects included a decrease in testosterone by the low-iso SPI relative to the MPI (P = 0.023) and high-iso SPI at d 29; an increase in dehydroepiandrosterone sulfate by the low-iso SPI relative to the MPI at d 29 and relative to the MPI and high-iso SPI at d 57; and increases in estradiol and estrone by the low-iso SPI relative to the MPI at d 57. In conclusion, soy protein, regardless of isoflavone content, decreased DHT and DHT/testosterone with minor effects on other hormones, providing evidence for some effects of soy protein on hormones. The relevance of the magnitude of these effects to future prostate cancer risk requires further investigation.
