Soy Protein Vs. Whey Protein - Who Wins?

There is no doubt about it, protein is essential for your body to function properly. Not only is it needed to build muscle mass, repair damaged tissue and form new cells to make your body grow bigger and stronger, but it also plays many other vital roles in the body. It's clear that protein is incredibly important but just how bad is it if you don't get enough?

Even if you’re not hitting the gym with the goal of getting big muscles, you will still need protein to help you repair and recover. In fact, while all the macronutrients (proteins, carbs and fat) are needed, if it came down to it, protein would definitely win out of those as the most important macronutrient.

As a general rule, those exercising at a high intensity need around 0.8 grams of protein per pound of body weight each day to function and recover optimally. As an example,That wild be 160 grams of protein per day for a 200 pound guy, or 96 grams for a 120 pound girl.

Sometimes, getting this much protein through a diet can be quite difficult, this is where supplements come into the equation.

Two of the most commonly used protein powders on the market are of course whey and soy. Let’s take a look at both, comparing the similarities between the two and the differences, and find out which is your best choice as a protein powder.

Whey

Whey is made from milk. If you’re familiar with the nursery rhyme, you’ll know all about curds and whey. The curd is the solid part of the milk that, if you didn't know, is used to make cheese, while whey is the liquid protein part of milk.

This "liquid protein" is collected, and used to make protein powder. Obviously this also means you can get whey protein in the dairy products too, such as the aforementioned milk, along with cottage cheese, regular cheese and even yogurt. So, what makes whey a great choice?

The main benefit you’ll get from making whey your main source of protein is the bioavailability. This refers to how well your body uses the protein. It doesn't matter what type of food you eat, or the exact protein content of a meal, you won’t digest all of the protein. However with whey, the bioavailability is around 90 percent plus, depending on the brand and type that you buy.

This is actually better than many whole food sources such as eggs, beef and pork.

The second big advantage that whey protein has is the cost. It is relatively cheap and easy to manufacture, plus the sheer demand for it makes it gram for gram one of the cheapest sources of protein you can buy. Again, even in comparison with whole foods, or inexpensive protein foods like battery farmed meat, whey is extremely cheap.

It’s also safe. Unless you’re allergic to dairy, whey protein has been used by bodybuilders and athletes for decades and has to go through rigorous testing processes to make it onto the shelves.

Any Downsides?

The only downside is, as mentioned, if you have a dairy allergy. If you have a full blown allergy, you’re best off avoiding whey, but if you’re just sensitive to dairy, you may do okay with a purer form of whey, such as an isolate or hyrolysate.

The only other consideration is the additives, thickeners and sweeteners they add to whey protein. There isn't anything inherently bad about these, but it’s a case of how you react to them personally. Often, the more obscure protein powders (such as pea, hemp or rice protein) tend to come as unflavored only, so don’t have any additives to pose the risk of a reaction. Most companies know that whey is their biggest seller though, so will do whatever they can to make it taste as good as possible to stand out from the competition.

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.