Soy Protein Supplements
Soy is the most widely used vegetable protein source. Soy protein is made from soybeans using water or a water-ethanol mixture to extract the protein. But, let’s be honest. Soy has never been big among those who take nutrition or bodybuilding seriously. This type of protein is often used only by vegetarians/vegans as an alternative to dairy-based protein powders and by those who do not tolerate lactose. Soy protein supplements are usually cheap and they are losing popularity among supplement users and the general public as we learn more about the soy.
Disadvantages of Using Soy Protein Supplements
Soy protein supplements are not very popular for many reasons:
- Soy protein powder is commonly derived from genetically engineered soy.
- Soybeans are said to be goitrogenic, meaning they can depress thyroid function.
- Soy protein powder contains phytoestrogens, which have been argued to disrupt endocrine function by mimicking the physiological effects of estrogen.
- Whole soybeans also contain a number of chemicals and proteins that would be harmful to humans if they were not removed prior to ingestion.
- There are many different processes that raw soybeans must undergo before they are ready to be consumed by humans in whole food products or as protein supplements.
- The consumption of large amounts of soy protein can cause abdominal pain among other disorders such as vomiting, headache etc.
Amino Acid Profile
Although soy lacks the essential amino acids methionine and lysine, it has a relatively high concentration of remaining essential amino acids. In other words, although most vegetable proteins are considered “incomplete,” soy protein can be considered a “complete” protein.
Soy protein has a relatively high amount of BCAAs, albeit lower than whey proteins’ BCAA content. Soy protein does have a significantly higher content of glutamine than whey, however, which is also an abundant amino acid in skeletal muscle and believed important for muscle protein anabolism.
Nevertheless, the protein profile in soy is poor. It is not a very high quality of protein, even if it contains a lot of it. The difference is quality over quantity. If a soy protein beverage contains 35 grams of protein, smart consumers know that very little of that is going to be absorbed by the body. Soy has a low biological value (BV) for protein at 74, or medium low. This is hardly ideal for a protein supplement. Furthering this, it has a low rating for Net Protein Utilization at 61. These numbers grade the ease of the digestive system to absorb and then use up the proteins in foods.
Types of Soy Protein Supplements
Soy protein is similar to whey protein in that there is a soy protein concentrate and isolate.
Soy protein concentrate is only 70 percent protein and about 23 percent fiber, which may cause stomach discomfort if taken before training.
Soy protein isolates are derived from the soy protein concentrate by removing most of the carbohydrates and any remaining fat. A soy protein isolate is almost 90% protein on a moisture-free basis. The removal of the carbohydrates tends to also remove most of the beany flavor that soy concentrates tend to retain. Soy protein isolates also typically have the lowest concentration of isoflavones.
Soy Protein vs Whey Protein
When soy protein is compared to whey protein, studies have shown that both may contribute to increases in lean body mass. When soy is compared to milk, which contains both casein and whey, milk leads to greater increases in lean body mass, possibly because casein protects against muscle protein breakdown. The net effect is a greater increase in muscle protein synthesis with milk than with soy, although soy is still effective.
Soy Protein and Weight Training
There is some evidence to suggest that soy may decrease or prevent the exercise-induced damage to muscle seen following a workout. At this point, there are few data relative to soy protein ingestion and accretion of lean body mass in conjunction with resistance training; therefore, more research is needed before definitive recommendations can be given.
Some Possible Benefits of Soy Protein on Your Health
- A number of studies have shown that soy has cholesterol-lowering and triglyceride-lowering effects.
- Soy-protein also seems to make the blood a little thinner, which may help support circulation and nutrient delivery of glucose to muscles.
- Soy contains compounds called isoflavones, which appear to be strong antioxidants and have been implicated in possibly decreasing the risk of developing cardiovascular disease and cancer.
- Because soy protein does not contain any lactose sugar those with lactose intolerance can consume it without any risk of intestinal disturbances.
Summing Up (Conclusion)
If you have an aversion to all animal products, soy protein is really your best choice. That being said, it’s important to understand that soy protein does carry certain risks. Anyone with thyroid disease or a predisposition to thyroid dysfunction, however, should limit the intake of soy-based protein food, due to its potential to affect hormone balance. The long term health risks associated with soy is just one reason why consumers are wising up and saying no to cheap, soy protein supplements. Furthermore, it is not a very high quality of protein (even if it contains a lot of it). That is the major reason why atheles and experienced fitness gurus never use soy protein. Whey protein is best for anyone without dietary restrictions, as it’s one of the most easily available, and most effective types of protein around. Whey products have, for some time, maintained their position as the gold standard in protein supplementation.