Improve Your Recovery & Lose Fat With Soy Protein
Soy protein has long been considered one of the best vegetarian sources of protein on the market. It is an inexpensive and a complete protein that contains all the amino acids, both essential and non-essential. In addition, most scientists would agree that soy protein production is more sustainable and environmentally friendly than dairy production1. While it has lost some of its popularity in recent years due to the rise of other vegetarian proteins such as pea and rice, it’s still considered a great choice for those who want a lactose free or vegetarian source of protein. But soy protein is more than just a source of protein, it can actually help you stay leaner and support better recovery from exercise.
Soy protein is high in compounds known as isoflavones. These have been researched quite extensively and have been shown to be quite beneficial for overall health as well as decreasing incidence of certain cancers. They are also excellent antioxidants and was shown in a recent study by Yoon & Park2 to help decrease oxidative stress after exercise. The study utilised rats and separated them into four groups:
1. Exercise & Isoflavone Supplementation
2. Exercise & No Isoflavone Supplementation
3. No Exercise & Isoflavone Supplementation
4. No Exercise & No Isoflavone Supplementation
The study was able to find that isoflavone supplementation alone was able to significantly reduce the abdominal fat pad, even if they also exercised. In addition, the isoflavone supplemented groups also had lowered triglyceride levels and also enhanced antioxidant action resulting in decreased oxidative stress post exercise.
While there were original concerns that soy protein and soy products may be negative to men’s testosterone levels due to the fact that certain isoflavones can increase the growth of estrogen-receptor positive and negative breast cancer cells. In other words, there were initial concerns that high intakes of isoflavones can increase oestrogen levels in the body, however more recent research has shown that “neither soy foods or isoflavone supplements will alter bioavailable testosterone concentrations in men”3.
Although it was an animal study, there’s been plenty of research that has shown the antioxidant ability of isoflavones. If you’re looking for a dairy protein alternative, soy protein is a great choice to not only help speed up recovery and help support your immune system, but also to potentially decrease fat mass around the abdominal area. And for those who are worried about soy products affecting testosterone levels, there’s definitely not enough evidence to warrant not using it. As with other protein sources, try to have 1-2 serves a day and more if you’re training frequency or intensity if increased.1. David Pimentel. 2006. Efficiency of Energy Use SSR The Organic Center Impacts of Organic Farming on the Efficiency of Energy Use in Agriculture . [ONLINE] Available at: http://www.organicvalley.coop/fileadmin/pdf/ENERGY_SSR.pdf. [Accessed 15 December 14].
2. Yoon GA, Park S. ‘Antioxidant action of soy isoflavones on oxidative stress and antioxidant enzyme activities in exercised rats.’ Nutr Res Pract. 2014 Dec;8(6):618-624. Epub 2014 Aug 30.
3. Hamilton-Reeves JM, Vazquez G, Duval SJ, Phipps WR, Kurzer MS, Messina MJ (2010). "Clinical studies show no effects of soy protein or isoflavones on reproductive hormones in men: results of a meta-analysis". Fertil Steril. 94 (3): 997–1007.