Soy Protein – The Truth

Soy is possibly the most controversial topic in the nutrition industry.

People tend to fall into two camps regarding soy. On the one hand, you have those (usually, but not always gym rats and bodybuilders) who demonize soy and stay as far away from it as possible.

Then there are those who never stop singing the praises of soy. (These tend to be vegetarians, or those who follow plant-based diets.)

And there’s your main advantage of soy protein – it’s a protein source for vegans and vegetarians. Plant-based diets are notoriously lacking in protein. While pescatarians and those who eat dairy can meet their daily protein needs with relative ease, those who eat no animal products whatsoever will really struggle with the 0.8 grams per pound target. Adding a soy protein supplement can help them do this.

But that’s about as far as the advantages of soy protein go.

First up as far as disadvantages go are the estrogenic compounds in soy. Soy has been linked with raising levels of estrogen. For anyone looking to build muscle mass, this is bad news. Ideally you want high levels of testosterone and low levels of estrogen. While one or two servings of soy per day is very unlikely to raise estrogen levels more than a small amount, it still has a bigger impact on estrogen than whey protein does.

When looking at bioavailabilty, soy tends to rank between 60 and 80 percent – not terrible, but it pales in comparison to whey.

A third factor to consider is cost. Soy protein will always be more expensive than whey, simply because it costs more to produce, and the demand is much lower. It’s seen as a specialist product, so companies can charge more for it.

Finally, take a look at the anti nutrients found in soy. Traditional fermented soy foods such as tempeh and miso actually have a number of health benefits, but these are a far cry from the soy you find in processed soy milk, man-made soy meat replacements and soy protein powders.

These anti nutrients can block vitamin and mineral absorption, and generally aren’t too great for you. Oh, and the taste – despite what you may hear, no one can truly say they look forward to a tasty soy shake the way they do with their double chocolate cookie dough whey shake!

To sum up, unless you have a specific reason for choosing soy protein, you’re much better off opting for whey. Even if you’re a vegan or can’t have whey, get your protein from plant-based whole foods first such as beans, nuts, seeds, or even soy beans before looking at processed soy protein supplements.