SOY GOOD?
Remember the game broken telephone? You likely played this game hundreds of times with your buddies back in your playground days. You probably never thought this innocent pastime could someday be the same situation conjuring up static between the lines of muscle gains. The lesson behind the game however, has unknowingly been powering your growth since the day you grasped your first dumbbell, or supplement for that matter.
Just as the words were rapidly spouted off in back then, critical research information has a way of losing certain key points as it trickles down to you — often becoming something completely different from the original findings, and devoid of crucial facts that can help drive you into new growth.
Such is the case with soy protein. If you’re looking for a complete, and accurate, understanding of the research behind soy … you’ve come to the right place. We’re digging into the scientific data that will have you hulling insane muscle, not to mention better health, out of this potent little bean.
The Science Says
Soy is a plant protein, but unlike ordinary plant protein foods, it contains all of the essential amino acids that the body needs for processes such as muscle growth. According to the Protein Digestibility Corrected Amino Acid Score (PDCAAS), which is the most accurate measurement of a protein’s quality for a human, whey protein (considered the gold standard in protein because it’s rapidly utilized, enhances immune function and has a near-perfect muscle-building profile of amino acids) is not necessarily the “best.” In fact, both soy and whey dial in at a 1 on the scale — the highest possible score and the same score as the almighty egg white. Eggs act as the key reference protein on this scale because of their complete amino-acid profile. As a comparison, take beef for example, which notches in at a score of 0.92. Beef is still a good quality protein, but certainly not one superior enough to hang with egg whites, soy or whey protein.
Is it thus safe to say these proteins are equal? Not at all — as with anything, there are pros and cons for each. It is true that soy supplies all of the essential building blocks needed for muscle growth and recovery, just as well as the others with a score of 1. "Soy protein is the only vegetable-based protein that is comparable to egg or milk-based protein," says bodybuilding nutrition specialist Chad Nicholls, who is known in the industry as The Diet Doc. "It's definitely an effective alternative."
According to research published in a 2005 issue of Experimental Biology, protein has a significant impact on muscle growth, regardless of its source. Researchers found that subjects who supplemented with either soy protein concentrate, soy protein isolate, a soy/ whey blend or whey protein isolate twice daily during 12 weeks of weight training, all experienced similar increases in muscle mass. A six-week study conducted at 1 Laurentian University (Sudbury, Ontario, Canada) found similar results when comparing soy and whey protein.
In an earlier study published in Nutritional Journal, researchers examined the effects of various types of protein supplements on muscle growth. Thirty-three male subjects were assigned to take either whey or soy, in the form of a protein bar, and underwent a nine-week training program. Results revealed that both soy and whey were equally effective in increasing lean body mass, however, soy appeared to have one important advantage: Those who supplemented with soy protein bars were able to combat muscle catabolism (muscle protein breakdown), which results from intense training, better than those supplementing with whey.
Further studies have shown numerous other health benefits of soy. "Plant sterols that come from soy have been shown, in combination with a healthy diet, to assist in lowering cholesterol levels," says Nicholls. Not to mention the research demonstrating its positive effects in relation to protecting the body from cardiovascular disease, and a number of cancers including colorectal, breast and prostate. However, for the bodybuilder first and foremost concerned with muscle growth, valuable information comes from studies on amino acids. Research has shown that soy contains high amounts of the potent amino acids glutamine and arginine when compared to whey. These two amino acids are extremely crucial, not only for their ability to enhance muscle recovery and aid in immune system function, but also in their ability to boost anabolic activity.
When compared to other protein sources, soy contains higher amounts of arginine. Arginine has been touted as a powerful stimulant of anabolic hormones, promoting the release of hormones such as insulin and GH. Arginine is also known to ignite the production of nitric oxide, which yields numerous benefits. This process increases blood flow to muscles and transports more nutrients, anabolic hormones and oxygen to tissues to speed up healing and enhance rates of protein synthesis.
Glutamine on the other hand, is essential during states of metabolic stress. In addition to decreasing muscle breakdown and reducing fatigue during workouts, glutamine has been shown to promote muscle glycogen accumulation, which is linked to an increase in muscle protein synthesis. Studies have also demonstrated marked increases in GH levels resulting from supplementing (even a couple of grams a day) with glutamine. For the die-hard bodybuilder, glutamine's multiple benefits may seem like common knowledge, but what many bodybuilders don't know is that soy protein has the highest concentration of glutamine among all protein sources — it's estimated to be double that of whey protein.
The Facts On Soy
1: Is Soy Is A Complete Or An Incomplete Protein?
FACT: Soy protein is a complete protein, meaning it contains all nine essential amino acids. Unlike many vegetable proteins that are considered to be incomplete, soy meets or exceeds the essential amino acid requirements necessary to drive growth during training.
2: If Soy Protein Has A Lower Biologic Value, Does This Mean It's Inferior?
FACT: BV and PER are out-dated and measures of protein's quality. The most accurate measure is the Protein Digestibility Corrected Amino Acid Score (PDCAAS). This measurement method ranks soy with a score of 1, which is the same in quality to both whey or egg.
3: Can Soy Proteins Reduce Testosterone Levels?
FACT: Numerous studies have shown that subjects taking soy had similar increases in muscle mass as those taking whey. The gains with soy wouldn't have been possible if it had negative effects on testosterone levels.
Girl Play?
Now here's where soy gets a bad rap. In addition to arginine and glutamine, "Isoflavones that are (also) found in soy protein may help to reduce soreness and inflammation and thus improve recovery time," Nicholls explains. "They've been shown to have powerful antioxidant effects." It's precisely these compounds however, that have given soy protein its reputation as a contributor to "feminizing" characteristics within bodybuilding circles.
When a particular scientific issue is under consideration, the only way one can get accurate information is the same a as in a game of broken telephone — by going back to the source, which in this case is the research. In recent years, scientists have been delving into the labs taking a closer look at the effects soy has on muscle growth, and more specifically the levels of testosterone. There are a handful of studies that disagree, but the majority of research on isoflavones, and their effect on hormone levels has shown no detrimental effects on muscle growth.
In a 2007 issue of the Journal of the International Society of Sports Medicine, researchers reported that subjects who were fed either soy concentrate, soy isolate or a soy/ whey combination (while also following a resistance training program) showed no differences in free and total testosterone levels — all groups also made similar gains in lean muscle mass. The findings thus concluded that soy was in fact, not an inferior source of protein as had been suggested in earlier studies.
Soy is made up of three major isoflavones called genistein, glycitein and daidzein, which are also referred to as phytoestrogens (meaning plant estrogens) and are similar in chemical make-up to the body's natural hormone estrogen. They're structurally very weak however — approximately 1,000 times weaker than the body's own natural hormone (which both men and women produce).
"While isoflavones do act to regulate the production and levels of estrogen within the body, for them to actually increase the body's estrogen levels, and thus compete with the anabolic effects of testosterone, a person would have to consume incredibly large amounts for a very long period of time," says Nicholls. Since numerous studies have shown significant muscle gains in those supplementing with soy, if there were any negative effects on testosterone, these gains simply wouldn't be the case. Essentially, the research on these "feminizing" compounds trickles down to one explanation: these pseudo-like estrogens may attempt to battle with testosterone, but they simply aren't strong enough to have any real negative effects on muscle growth.
The scientific dilemma on soy really isn't all that complicated: Just as whey can help you build muscle tissue, so too can soy, and soy protein provides the bonus of additional health benefits. And its low cost certainly makes soy a worthwhile option to be used in conjunction with other quality protein sources.
Soy Many Types
Soy: Derived from the soybean, soy is made up of approximately 40% protein, 20% fat, 35% carbs and 5% ash before processing. Soy is often devoid ' of cholesterol, high in phytochernicals and. in some cases, high in fiber. It also provides the body with a respectable amount of potassium, zinc. iron, vitamin E, phosphorous and the full B-complex vitamins.
Soy Concentrate: Soy protein concentrates, which are 70% protein and 30% carbs and fats (good fats), are made from defatted soy flakes that have been processed using water or alcohol. Through processing, most of the beans' dietary fiber is also retained, making it a highly digestible source of amino acids.
Soy Isolate: Soy protein isolates result from further processing of soy concentrates. They're made up of 90% protein and, as with whey protein isolates, are the most pure and highly refined form. There's also less of a "soybean" taste with this particular form of soy protein because most of the carbs and fats have been removed.
Soy Vs. Other Protein Powders
WHEY SOY CASEIN EGG
OVERALL RANK High Moderate-High Moderate Mod.
ESSENTIAL AMINO ACIDS High Moderate Moderate Mod.
PROTEIN SYNTHESIS High Moderate Moderate Mod.
PREVENT MUSCLE BREAKDOWN Low Low Moderate High
TASTE High High Moderate Low
BIOAVAILABILITY 1.0 1.0 1.0 1.0
"Soy ranks slightly lower because it has lower levels of the branched-chain amino acids (leucine, soieucine and valine) than whey has.
""As related to speed of digestion. Faster-digesting proteins scored lower in this category. "Based on solubility (how well each powder mixes with water).
"Based on Protein Digestibility Corrected Amino Acid Score (PDCAAS), in which 1.0 is a perfect score.
Ontario, Canada-based writer Sommer Robertson has worked in the bodybuilding industry for more than a decade, with a special emphasis in kinesiology and health sciences, as well as psychology.
