Before the days of casein, egg and the almighty whey in all its cross-filtered, ion-exchanged, microencapsulated, peptide-bonded glory, the lowly soybean filled the muscle building bill for
thousands of bodybuilding hopefuls.
The choice makes sense. Gram for gram soy has a higher percentage of pure protein than almost any other substance in an unaltered state - about 90 percent. It contains no fat or cholesterol. It's flavorless and it mixes well with everything from milkshakes to meatloaf. It's perfect! Well... almost.
Long before other options came along, soy was known to have its shortcomings. It couldn't be condensed in pill form, so you had a large, chalky tablet that took up to a minute to chew and seemed impervious to saliva. For all your trouble you wound up with a whopping quarter of a gram of protein.
Powdered soy products fared much better but they were still far from perfect. One shortcoming is that soy is an incomplete protein because it lacks the essential amino acid methionine. When it's mixed with milk, the protein chain is completed, but on its own much of the protein would be lost. Being a plant protein, it has a lower rate of absorption than protein from animal sources.
Soy ruled the supplement market until the late 1960's when a young chemist by the name of Rheo H. Blair attempted to create a better protein supplement. He experimented with a combination of whole egg, whey and milk isolates in an effort to achieve an amino-acid formula that was as close as possible to the most nearly perfect protein for human consumption - mother's milk. As innovative as he may have been, Blair didn't have the resources to market his product the way big supplement companies did, and his discovery went virtually unknown except for bodybuilders and nutritionists who realized his product was far superior to the name brands. Ironically, most ensuing protein manufacturers have adopted Blair's concept of mixing egg, milk and whey.
Today many companies exclusively use whey protein because of its high bio-availability. In simple terms that means it has a very low molecular weight in relation to its nitrogen-retaining properties, making it an excellent choice for shakes and food bars. Soy, on the other hand, is all but gone from the scene and is a rarely used source of protein in products geared to bodybuilders.
If the advancements in protein technology haven't been enough to put soy protein out to pasture, there's recently been more unsettling speculation. According to some sources, soy may elevate estrogen level! It does this through the phytoestrogens genestein and diadzein, which are inherent to raw soy. Apparently these phytoestrogens act as a weak estrogen and bind to estrogen receptor sites. With all that whey has going for it and all that soy has going against it, the verdict appears to be clear cut. Yet more and more bodybuilders are starting to use soy protein again. Why?
As with all studies and speculations, there are two sides to the story. On the surface the fact that soy attaches to estrogen receptors may sound like a detriment, but by docking onto estrogen receptor sites, these phyto-chemicals may prevent stronger estrogens from binding, thus lowering overall estrogen level. This process is not unlike the way the anti-estrogens Clomid, Nolvadex, and Cyclofenil work. Each is an estrogen itself, but by occupying estrogen receptors they prevent excess estrogen from building up, as is the case from the aromatization of steroids. Therefore, we can safely say soy more likely acts as anti-estrogen, which in turn may increase testosterone. A good deal of speculation still exists in regard to the effect of food on hormone levels, but our old friend the soybean has some other remarkable qualities.
And if all this isn't enough, soy is still the most economical source of supplemental protein. Most soy products today even contain additional methionine to balance out their amino-acid profile. Powdered soy makes an excellent addition to meal replacements by boosting the overall protein content. You can also cook with soy by using it as a partial replacement for flour, upping the protein content in an otherwise high-carb meal.
If you're a bodybuilder looking for as much muscle-growing nitrogen as possible, you want to get it from a variety of sources -meat, eggs, whey, and the forgotten standby, soy. Even among today's high-tech protein supplements, it's proving itself a worthy contender. When soy was the exclusive source of supplemental protein, it helped to pack on a lot of muscle for thousands of bodybuilders. What it did then... it can do now.