Soy Protein vs. Whey Protein: And the Winner Is…

It is true, there are quite a few health benefits associated with soy protein. But in a side by side comparison, of whey protein vs. soy protein, whey protein comes out way ahead of the competition.

Advantages of Soy Protein:

• Only plant based protein that contains all eight of the essential amino acids, important to vegetarians and vegans
• No cholesterol and low in saturated fat
• Good source of fiber, iron, and calcium
• No lactose issues for those intolerant to lactose
• Decreases bad (LDL) cholesterol
• One of the least expensive sources of dietary protein
• Offers significantly higher amounts of glutamine (a non-essential amino acid great for muscle building and muscle repair), and arganine (a non-essential amino acid that helps fight physical and mental fatigue and facilitates muscle growth), two very important ingredients when it comes to strength and conditioning

Photo credit: The Unseasoned Wok

Disadvantages of Soy Protein:

• Fiber in soy can be harsh and tough. May cause bloating, nausea, and constipation. Not good for sensitive digestive tract
• Contains phytates that may inhibit mineral digestion and iodine absorption, leading to weaker bones and decreased thyroid function
• Contains trypsin inhibitors that block the action of typsin and other enzymes that are needed for protein digestion
• Contains isoflavones or phytoestrogens, which have the potential to increase estrogen levels. Excess estrogen can exacerbate other estrogen related issues
• May cause increased estrogen in males, which may suppress production of testosterone, reduce sex drive, and increase the incidence of gynecomastia

Consuming natural foods, like soy some burgers, soy milk, tofu, and soy nuts has cardiovascular benefits due to the high fiber, vitamin, and mineral content, as well as decreased saturated fat (especially when compared to animal proteins and red meat).

However, reviewed in 2006, a decade-long study showed that soy supplements were not as heart healthy as initially thought. Soy protein does lower bad cholesterol but does not raise good cholesterol. Findings suggest that soy does not reduce the incidence of hot flashes in post-menopausal women as once thought, and they do not prevent cancers of the prostate, breast, or uterus.

In an article written by Marjorie Geiser, RD, NSCA-PT, she states that when “substances (phytoestrogens/isoflavones) are concentrated, as when in supplement form, it is believed that too much of a good thing may actually be harmful to your health. Therefore, consuming soy in forms other than food is not recommended at this time.”

Advantages of Whey Protein:

• High Quality, Complete Protein that exceeds the requirement for essential amino acids.Very high Biological Value at 104 (compared to soy at 74)
• Natural, nutrious, and highly digestible product rich in vitamins and minerals
• Offers major boost to the immune system/Anti-oxidant properties
• Improves health of gastrointestinal tract though prebiotic properties, which promote growth of beneficial bacteria
• High in branched chain amino acids (BCAA’s) which maintain muscle tissue, help preserve precious muscle glycogen stores, and prevent muscle breakdown during exercise
• Increased rates of protein synthesis, increased lean muscle mass accretion, improved strength, improved recovery from exercise, and a decrease in musculoskeletal injuries
• Facilitates weight loss by increasing satiety, maintaining fat free mass, and releasing of hormones that boost metabolism

Disadvantages of Whey Protein:

• Supplements can get expensive
• Digestive issues, especially for those who are lactose intolerant (However, in most concentrated forms, like whey isolate, much of the lactose has been removed, so even those who are lactose intolerant can safely use it)
• Liver and kidney issues with long-term, excessive overconsumption
• Weight gain when overall caloric intake is not monitored

Conclusion: Soy Protein vs. Whey Protein

Without totally diminishing all the positive benefits that soy protein offers the consumer when ingested in FOOD form, whey protein is clearly the winner when it comes to protein supplementation. It is nutritious and highly efficient with less of the risky and unfavorable side effects associated with soy supplements. However, it is still a wise idea to consult your doctor before beginning any supplement plan to discuss possible ways it may effect you personally.

Bond, Owen. (December 20, 2010). The Dangers of Soy Protein Powder. Retrieved on November 21, 2011 from

Campbell, Bill, PhD, CSCS, FISSN. (Downloaded 3-25-2010). Protein Needs for Athletes. NSCA Hot Topic Series. Retrieved Oct. 19, 2011 from

Geiser, Marjorie, RD, NSCA-PT. (October 2003). The Wonders of Whey Protein. NSCA’s Performance Training Journal, vol. 2, number 5, 13-15. Retrieved Oct. 7, 2011 from

Matthews, Ryan. (April 26, 2011). What are the Dangers of a Whey Protein Supplement? Retrieved on Nov. 3, 2011 from

Soy Protein. Retreived on November 21, 2011 from

Thornton, Aaron. Whey vs.Soy Protein Powder. Retrieved on November 21, 2011 form

Whey Protein vs. Soy Protein–Which is the Best? Retrieved on November 21, 2011 from


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"Any change requires an initial period of discomfort until the body adjusts to the new demand." - Author unknown

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