Soy, Egg and Whey Protein Effects on Fitness Training: A Comparative Study

by | May 11, 2013 | Healthy Choices

 

 

 

Protein, composed of amino acids, is essential to the body for cell repair, growth and various metabolic and hormonal activities. 12 In the fitness industry, personal trainers push the use of protein dramatically and body builders and fitness models swear by its consumption. Others question the efficacy and need for high amounts of protein during fitness training. Proteins come in various forms ranging from animal to plant based, each with its own benefits and drawbacks. The major categories of protein are gelatin, wheat, beef/poultry/fish, soy, egg, milk, casein, bovine colostrum and whey.3 The three main proteins used are soy, egg, and whey.

Soy protein is controversial in nature. People either swear for it or against it. Protein, composed of amino acids, is essential to the body for cell repair, growth and various metabolic and hormonal activities. 12 Soy is low in methionine, an essential amino acid, and lysine.3,13 An essential amino acid cannot be made by the body and must be obtained from the diet. Certain production techniques can either eliminate or lower these two amino acids further and oft times the consumer is unaware of the production methods of a company.13

Peer-reviewed studies are demonstrating positive results in sculpting body composition in those who are moderately overweight.5 Soy protein was also shown to be occasionally helpful in lowering cholesterol in those who were hyperlipidemic.6 However, this is not always the case as other studies also demonstrated an increase in the LDL cholesterol of participants using a soy protein isolate diet. The article stating that the reduction of cholesterol was positive did mention that more study was necessary because the same results also occurred using other forms of protein.  In this case, it may very well be the protein itself and potential reduction of carbohydrates that lowered the cholesterol levels.

One fascinating study demonstrated that there is a connection between soy protein and the decrease of leptin and e-selectin.14 While the reduction of e-selectin is beneficial since it increases inflammation in the body, the decrease in leptin is not; especially in anyone who is trying to lose weight or maintain current weight. Leptin’s role in the body is to signal the brain that there is enough fat for the body to avoid starvation. When the body is deficient in leptin, the brain is told that food (energy) is needed. Therefore, if soy decreases the amount of leptin in the body it would then trigger the consumer to increase his intake of food in attempt to satisfy this need.

Soy protein was also demonstrated to induce fatty liver disease in obese rats and to increase the risk of hypothyroidism.7, 16 Both of these conditions are highly prevalent in our current society and need not be aggravated further.

Much like all other legumes and grains, soy contains phytic acid that chelates certain minerals like zinc and iron, leaching them from the body, and potentially creating deficiency.  The other downside to using soy protein, especially in the United States, is that, according to Wikipedia, 98% of the soy is genetically modified Roundup Ready version. With a multitude of other countries banning the usage of genetically modified species and conducting studies with positive implications toward cancer of these species, it would behoove a fitness enthusiast to select a different source of protein.

Egg, or ovalbumin, protein is a complete protein and is used as the reference standard for comparing all other protein supplements.3 The studies were conflicting on this particular protein. For instance, in one study a finding that utilizing egg protein to increase protein consumption in older individuals failed to show an increase in muscle mass and in another study it says just the opposite and by the same researcher!9, 10 According to the text, the nitrogen balance is kept positive when using egg protein, which allows for the muscle formation to occur.3

Whey protein has a multitude of studies done on it. It is one of the two highest-quality sources of protein available and is digested easily by most people.3 The best source to use is the whey protein isolate as it is the purest form available and offers many health benefits such as GI tract repair with antimicrobial properties, increase of lean muscle mass, improved body composition, prevention of cardiovascular incident and osteoporosis.1 And if that wasn’t already enough whey protein isolate reduces fatigue during exercise.18 People are less likely to be allergic to whey protein than egg white proteins and the whey proteins are often cheaper. Whey protein isolate is the purest in form with it ranging between 90-94% protein, the concentrate is higher in fat and slightly lower in protein ranging from 80-90% protein and the hydrosylates are the lowest in quality of the proteins.

When it comes to protein choices consumers definitely have choices available, and knowing which protein is the best source and value is essential. Although the studies show that soy protein is an equally viable source of nutrition for fitness training the fact that most soy is genetically modified in our country with a host of health consequences must be taken in to account. Secondly, we don’t often know the preparation method of the soy protein leaving to question the methionine and lysine content issue. Furthermore, soy protein is not fermented and therefore, is not something that should be consumed by humans and can lead to an increase in fatty liver disease and hypothyroidism. Egg, or ovalbumin, protein is the standard for testing purposes, but with its high expense and potential allergenic response it doesn’t rank as the most beneficial protein to consume. Whey protein, especially the isolate form, is ranks superior as far as protein supplementation for fitness training goes.8 During fitness training the body undergoes a great deal of oxidative stress and whey protein is helpful in mending the degradation of the ROS.  Whey protein isolate is high in protein content, a complete amino acid profile and keeps the body in a positive nitrogen balance for the muscles to repair and grow, which is key for fitness training.

 

  1. Abrahão, V. (2012). Nourishing the dysfunctional gut and whey protein. Current Opinion in Clinical Nutrition & Metabolic Care, 15(5), 480-484.

 

  1. Berg, A., Schaffner, D., Pohlmann, Y., Baumstark, M. W., Deibert, P., König, D., & Gollhofer, A. (2012). A soy-based supplement alters energy metabolism but not the exercise-induced stress response. Exercise immunology review, 18, 128.

 

  1. Campbell, B., & Spano, M. A. (2011). NSCA’s Guide to Sport and Exercise Nutrition. Human Kinetics 10%.

 

  1. Candow, D. G., Burke, N. C., Smith-Palmer, T., & Burke, D. G. (2006). Effect of whey and soy protein supplementation combined with resistance training in young adults. International journal of sport nutrition and exercise metabolism, 16(3), 233.

 

  1. Deibert, P., Solleder, F., König, D., Vitolins, M. Z., Dickhuth, H. H., Gollhofer, A., & Berg, A. (2011). Soy protein based supplementation supports metabolic effects of resistance training in previously untrained middle aged males. The Aging Male, 14(4), 273-279.

 

  1. El Khoury, D., & Anderson, G. H. (2013). CURRENT OPINION Recent advances in dietary proteins and lipid metabolism. Curr Opin Lipidol, 24, 000-000.

 

  1. Hakkak, R., Al-Dwairi, A., Fuchs, G. J., Korourian, S., & Simmen, F. A. (2012). Dietary soy protein induces hepatic lipogenic enzyme gene expression while suppressing hepatosteatosis in obese female Zucker rats bearing DMBA-initiated mammary tumors. Genes & nutrition, 7(4), 549-558.

 

  1. Hoffman, J. R., & Falvo, M. J. (2004). Protein-Which is best. Journal of Sports Science and Medicine, 3(3), 118-130.

 

  1. Iglay, H. B., Apolzan, J. W., Gerrard, D. E., Eash, J. K., Anderson, J. C., & Campbell, W. W. (2009). Moderately increased protein intake predominately from egg sources does not influence whole body, regional, or muscle composition responses to resistance training in older people. JNHA-The Journal of Nutrition, Health and Aging, 13(2), 108-114.

 

  1. Iglay, H. B., Thyfault, J. P., Apolzan, J. W., & Campbell, W. W. (2007). Resistance training and dietary protein: effects on glucose tolerance and contents of skeletal muscle insulin signaling proteins in older persons. The American journal of clinical nutrition, 85(4), 1005-1013.

 

  1. Klok, M. D., Jakobsdottir, S., & Drent, M. L. (2007). The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review. Obesity reviews, 8(1), 21-34.

 

  1. Kreider, R. (2011). Protein. In B. Campbell & M. Spano (Eds.), NSCA’s guide to sport and exercise nutritionTampa: National Strength and Conditioning Association.

 

  1. Kuiken, K. A., & Lyman, C. M. (1949). Essential amino acid composition of soybean meals prepared from twenty strains of soybeans. Journal of Biological Chemistry, 177(1), 29-36.

 

  1. Rebholz, C. M., Reynolds, K., Wofford, M. R., Chen, J., Kelly, T. N., Mei, H., … & He, J. (2012). Effect of soybean protein on novel cardiovascular disease risk factors: a randomized controlled trial. European journal of clinical nutrition.

 

  1. Sánchez, O. A., Miranda, L. M., & Guerra-Hernández, E. (2011). Prevalence of protein supplement use at gyms. Nutrición hospitalaria: organo oficial de la Sociedad Española de Nutrición Parenteral y Enteral, 26(5), 1168.

 

  1. Sathyapalan, T., Manuchehri, A. M., Thatcher, N. J., Rigby, A. S., Chapman, T., Kilpatrick, E. S., & Atkin, S. L. (2011). The effect of soy phytoestrogen supplementation on thyroid status and cardiovascular risk markers in patients with subclinical hypothyroidism: a randomized, double-blind, crossover study. Journal of Clinical Endocrinology & Metabolism, 96(5), 1442-1449.

 

  1. Tang, J. E., & Phillips, S. M. (2009). Maximizing muscle protein anabolism: the role of protein quality. Current Opinion in Clinical Nutrition & Metabolic Care, 12(1), 66-71.

 

  1. Thomson, I. S. I. (2011). Jing Liu, Ying Miao, Zheng Zhao and Wenbo Zhao. Asian Journal of Animal and Veterinary Advances, 6(12), 1214-1223.