Whether you’re vegan, lactose-intolerant or just prefer to avoid dairy, it can be tough to find a high-quality protein powder when almost all options are made with dairy-based whey or casein. Nondairy powders have plenty of advantages, however, with soy being at the top of the pack for its complete amino acid profile and cardiovascular benefits.
Soy Powder 101
Unlike other plant-based protein powders, soy is a complete protein that contains all essential amino acids. A standard 30-gram scoop contains the same 20-plus grams of protein that whey powder does but less fat and cholesterol. In the results of a study published in 2013 in “Journal of Women & Aging,” subjects with osteoporosis who supplemented with soy isolate powder gained both muscle and bone strength over the course of 12 weeks, even if they did not exercise.
Soy may also have additional benefits over other plant-based powders. In an article published in 2009 in the journal “American Family Physician,” researchers reported that soy consumption contributes to lower blood cholesterol levels and triglyceride levels and may reduce the risks of some cancers. Processed soy may not have the same effects, however, and may even raise risks of estrogen-driven diseases such as breast cancer, according to Dr. B.J. Hardick. Choose organic, non-GMO soy for the most benefits.
Other Plant-Based Powders
Along with soy, some health food stores also stock pea, hemp or brown rice powders. One primary disadvantage of those powders is that they’re not complete proteins; often, they also contain less protein per serving than soy and dairy-based powders. While all proteins have the potential to contribute to muscle building and enhance the effects of resistance training, there is not as much research associating pea, hemp or brown rice protein powders with positive gains in lean muscle mass, strength and power or with improved body composition simply because soy, whey and casein are more commonly studied.
Finding the "Best"
It’s difficult to call any protein powder the “best” because what’s best for one person may not be best for another. Soy does have a handful of clear advantages over other vegan protein powders, but it’s not guaranteed to affect everyone who takes it in the same way -- and no protein supplement will prove very beneficial unless you combine it with regular exercise and a healthy, balanced eating plan. For individualized guidance on adding protein powder to your diet, speak with your doctor.