Supro® Soy Protein For Fitness and Health

The soybean, a mainstay of the Asian diet, was considered by the ancient Chinese to be one of the five sacred grains, along with rice, wheat, barley, and millet. It dates back to 2838 B.C. in China, the 6th century in Japan, and the 17th century in Europe. The United States became interested in the soybean in the 1920's when it's full nutrient value was finally appreciated.

There is an increasing body of scientific evidence to support the role of Supro" isolated soy protein as the protein of choice, not only for elite athletes, but also for the general population including children, seniors and those recovering from illness or trauma.

Supro" brand of isolated soy protein was initially developed in the early 1960's for use in infant formulas. Protein Technologies International was instrumental in getting Food and Drug Administration (FDA) to approve soy protein for that purpose. It was shown that soy protein easily supports the needs of new-born and young children. Infants have a much higher amino acid requirements per kilogram of bodyweight than adults, and Supre soy protein meets these most stringent tests of all - growing a healthy baby. Supro's* Amino Acid profile closely meets human requirements and exceeds the FAO/VMO/UNU minimum recommendations for all essential amino acids for pre-school and school age children and for adults. It has the highest possible "Protein Digestibility Corrected Amino Acid Score" (PDCAA), equal to 1, equivalent to milk and eggs, and better than beef. The PDCAA is mandated by the FDA as the measure of protein digestibility. Supro* can maintain positive nitrogen balance when fed as the sole protein source at minimum intake levels.

But what about the other protein rating scales that show soy protein as being inferior to milk and egg proteins? The Protein Efficiency Ratio (PER) has been used for many years as the bench-mark for rating protein quality. The PER is determined by how well newly weaned baby rats grow, not how well a baby human grows. Rats require milk which is high in sulphur containing amino acids like methionine to make sulphur-rich hair proteins (keratins). Cow's milk is closer to a baby rats requirements (cows are also hair covered animals) than to a baby humaWs requirement. Similarly, the Biological Value (BV) is also a protein rating based on a weaning rat's requirements and not on the needs of a human baby. For years the dairy industry has misled people by promoting milk protein as having a high PER, and inferring that cow's milk is the best milk for the human baby. It is interesting to note that human milk rates inferior (lower PER) to cow's milk as a milk for baby rats, and if one follows this line of reasoning, then it would be unwise to give human milk to human babies.

There has been a lot of misinformation about the quality and properties of milk and whey protein. Some companies claim that their whey protein has a biological value (BV) of over 150. In actuality, nitrogen balance studies demonstrate that the BV of whey protein in humans appears to be some where around 70. (The FDA has recently clamped down on manufactures who overstate BV's and it's unlikely that such claims will be allowed in the future).

Soy proteins are quickly gaining favour in the competitive sports supplement market. The need to promote muscle growth and support lean muscle mass makes protein supplementation an essential part of a sports nutritional programme. More athletes are discovering that soy protein easily meets those needs and provides a nutritional bonus that whey and other animal proteins don't provide. Isolated soy protein is high in branched chain amino acids (BCAA's) and arginine (which stimulates the release of anabolic hormones), increasing the athlete's ability to build muscle mass and maintain lean body tissue." Soy protein is also high in glutamine (over twice as much as whey protein), an amino acid which is the body's primary carrier of nitrogen to skeletal muscle and other tissues, and is the key to stimulating muscle synthesis and buffering lactic acid build up. Glutarnine also increases growth hormone activity and strengthens immune capacity.

Supro" isolated soy protein has been used in clinical trials for more than 10 years; in that time, it has been used in more than 200 studies involving Olympic, professional, and collegiate (Division I level) athletes. Recent studies utilizing Supre have focused on specific aspects of the soybean that can benefit professional athletes, including reduced oxidative stress, anti-catabolic effects, effects on fat metabolism (through its effects on thyroid function), arginine/glutamine's role in performance, and the role of calcium and iron for female athletes. Researchers concede that soy protein's many benefits may not come from one specific action, but from the interrelation of a number of factors, including amino acids, saponins, trypsin inhibitors, soy globulins and isoflavones. In addition, soy's amino acids have been found to convert to organic acids and ketone bodies in the liver, then enter the body's energy pathways in those forms, which may enable the body to bum more fat and augment the anabolic process.

Isolated soy protein may hold other benefits for athletes and fitness enthusiasts. For instance, as athletes begin to lose body weight, their metabolism may "fight back" and slow down. A study found that consuming 25 to 50 grams of soy protein daily may help to stop the thyroid from slowing down. Suprol soy protein is high in iron, so it may reduce the threat of "sports anaemia", the iron loss caused by intense training which can cause reduced capacity for exercise due to the crucial role of iron in both oxygen transport and utilization.

Soy protein is able to reduce fatigue after intense training. Romanian athletes who supplemented their diets each day with 1.5 g of soy protein per I kg of bodyweight reported decreased fatigue, along with increased lean muscle mass, decreased body fat, and more haemoglobin in the blood.' These results were repeated with Chinese national teams, including weightlifting teams. Again, strength was improved along with resistance to fatigue. A recent Ohio State study looked at oxidative stress and the antioxidant effects of soy versus whey, and found that the phytonutrients in soy may contribute to lessening muscle injuries and soreness. Further evidence that soy protein aids athletes comes from a study with seven top women gymnasts (14 years old) who were given a supplement of soy protein (I gram per I kg of bodyweight a day) for four months during heavy training. Lean body mass was slightly improved, and thyroxin (a thyroid hormone associated with protein synthesis) increased. A control group saw a decline in thyroxin and an increase in urine mucoproteins.

According to David Weir, assistant athletic trainer with Texas A&M in College Station, Texas, and Dave Ellis, the assistant director in charge of nutrition at the University of Nebraska, "Soy protein is exactly on target for what. hard working muscle needs as far as its amino acid profile. It's also a potent antioxidant and contains great phytonutrients"

In his book, The Testosterone Syndrome, Eugene Shippen reported that when high levels of phytoestrogen's fit into a male's estrogen receptor sites, they stimulate the liver to process and excrete excess estrogen. There are initial indications that soy proteins block aromatase - the conversion of testosterone into estrogen - a concern for bodybuilders. Soy protein does not have estrogenic activity in males, so even consuming 300 grams of soy protein daily shouldn't have any anti-anabolic effects. The increases in muscle mass and decreases in body fat seen in soy protein supplementation studies with athletes further support the case that soy protein won't counteract anabolic processes in exercising individuals. No evidence exists that soy protein has estrogenic effects in athletes, and it may even have anabolic effects greater than milk proteins (the usual control-group supplement in these studies).

Soy protein has many health promoting and disease preventing qualities in addition to it's proven value as a superior protein for athletic performance. Soy protein has been shown in more than two hundred published scientific studies to: decrease plasma cholesterol; reduce the risk of Coronary Heart Disease; reduce the risk of certain cancers including breast cancer and prostate cancer; reduce the risk of osteoporosis; and to decrease the load placed on the kidneys. For long term fitness training with the added benefits of helping to maintain optimum good health and disease prevention over one's lifetime, soy protein deserves respect as an ideal protein for all humans, including elite athletes and hard-lifting bodybuilders.


  1. Stroescu V, Dragan 1, Georgescu E. "Effects of Supro brand isolated soy protein supplement in male and female elite rowers." XXVth FIMS World Congress of Sports Medicine. Athens, Greece, 1994.
  2. Dragan 1, Georgescu E, losub I, Baloescu R, "Effects of Supro Brand isolated soy protein supplement in top swimmers." Xth FINA World Sports Medicine congress, Kyoto, Japan, 1993.
  3. Min HG, et al. "Effects of Supro high-energy beverage powder on physiological functions of athletes." CSSC-Chinese National training Bureau States Sports Medicine Commission Study. 1994.
  4. Forsythe WA. "Soy protein, thyroid regulation, and cholesterol metabolism." Journal offutrition. 123.3;619S-623S (1995) 5) Nickerson HJ, Tripp HJ. "Iron deficiency in adolescent cross-country runners." Phys. Sports Med. 11:60 (1983).
  5. Pate R. "Sports anaemia: a review of the current literature." Phys. Sports Med. 11: 115 (1983).
  6. Puhl JL, et al. "Erythrocyte changes during training in high school women cross country runners." Res. Q. Exer. Sport. 52:484 (1981)

Supro® is the registered trade mark of Protein Technologies International