Myth busting: Soy supplements are not an issue for bodybuilders, say researchers

By Annie-Rose Harrison-Dunn

- Last updated on GMT

Reasearcher bust myths surrounding soy protein and strength training
Reasearcher bust myths surrounding soy protein and strength training

Related tags: Whey protein

Short-term supplementation with soy and whey protein does not lead to pro-estrogenic or anti-anabolic effects in bodybuilders, according to new research.

The study, published in Journal of the American College of Nutrition​, reviewed the effects of soy and whey protein supplementation on testosterone, sex hormone binding globulin (SHBG), and cortisol responses to an acute bout of resistance exercise like weight lifting.

The team behind the study noted that there is a common belief among fitness enthusiasts that soy-based products differ from animal-based protein products - with concerns over the potentially pro-estrogenic or anti-anabolic effects of soy protein.

"Although such fears may largely stem from bodybuilding mythologies, there is limited research on soy protein supplementation and its acute effects on hormonal responses to heavy resistance exercise,"​ explained the authors - led by William Kraemer from the University of Connecticut, USA.

The team revealed that while 14 days of supplementation with soy protein does appear to partially blunt serum testosterone, it does not have pro-estrogenic or anti-anabolic effects. In addition, they reported that whey protein influences the response of cortisol (a steroid hormone) following an acute bout of resistance exercise by blunting its increase during recovery. 

"Contrary to popular misconceptions, soy protein supplementation does not appear to hinder anabolic signaling postexercise by means of eliciting increases in estradiol concentrations​," wrote the researchers.

“This study starts to unravel and provide some insights into one of the real urban myths about soy protein and resistance exercise in men,”​ said Kraemer.

Methodology

The study used a sample of ten resistance-trained men in their early 20s. The participants where split between three protein supplementation groups: whey protein isolate, soy protein isolate, or a maltrodextrin placebo control.

For a period of 14 days participants consumed 20g of their assigned supplement at the same time each morning. No other supplements were allowed during the trial. After which the participants would perform six sets of heavy resistance squats at ten reps each using 80% of their maximum lifting weight.

Source: Journal of the American College of Nutrition

Published online ahead of print, doi:abs/10.1080/07315724.2013.770648
“The Effects of Soy and Whey Protein Supplementation on Acute Hormonal Reponses to Resistance Exercise in Men”
Authors: W.J. Kraemer, G. Solomon-Hill, B. M. Volk, B.R. Kupchak, D.P. Looney, C. Dunn-Lewis, B. A. Comstock, T. K. Szivak, D. R. Hooper, S.D. Flanagan, C. M. Mares, and J.S. 

Related news

Show more

Related products

show more

Game On: Time to Power Up E-Sports and Gaming

Game On: Time to Power Up E-Sports and Gaming

Applied Food Sciences | 30-Nov-2020 | Technical / White Paper

Don't sleep on E-Sports. Gamers are an influential consumer-base with tremendous purchasing power. Yet, certain ingredients are powering this space....

Next-wave sports nutrition innovation today

Next-wave sports nutrition innovation today

ADM | 28-Oct-2020 | Technical / White Paper

Today’s consumers are passionate about embracing health in many aspects of their lives, starting with customizing their nutrition. Rooted in proprietary...

Lanconone®: Game Changer in Rapid Joint Recovery

Lanconone®: Game Changer in Rapid Joint Recovery

Enovate Biolife LLC | 01-Oct-2020 | Infographic

Sports nutrition supplements with joint health claims were one of the top ingredients by market share within the joint health supplement category. Lanconone®...

Related suppliers

1 comment

synthroid for thyroid

Posted by Pat Cameron,

One of the things I am not supposed to take is soy. As a distributor of Relive I am not able to use my own product. It is a problem with the medication not being as effective. Is there anything I can do about this as I have much product I would like to use....?

Report abuse

Follow us

Products

View more

Webinars