The most popular choices may be unsuitable for people who have food allergies/intolerances or adhere to vegetarian/vegan diets. For these, rice protein is a viable and increasingly available alternative.
Most bodybuilders view rice simply as a source of starchy carbs. Rice, however, represents a significant source of both calories AND protein in developing countries, as the protein quality is superior to that of most other cereal grains. As such, some of the new concentrates can hold their own against the competition.
For example, Oryzatein, a rice protein powder made by Axiom Foods, has a biological value (BV) and PDCAAS (protein digestibility corrected amino acid score) comparable to casein (77 and 1.00, respectively).
Numbers like that are why rice protein supplements are growing in popularity among vegan bodybuilders, such as Mike Mahler.
Surprised? One misconception about plant proteins is that they have little value for building muscle, because they’re “incomplete”—that is, limiting in one or more essential amino acids. But this is critical only when a particular plant protein is the primary source in the diet…it’s much less important in a mixed diet, where the limiting amino acid(s) can be supplied by other foods. Thus, “vegetarian” sources of protein—such as rice—can be used to fulfill total protein requirements for omnivores, too.
Rice protein has its virtues.
For one thing, it’s a good source of the branched chain amino acids, leucine, isoleucine and valine, which are useful for reducing protein catabolism and stimulating protein synthesis.
It may also have some health benefits: In one study, for example, rice and/or soy protein feeding inhibited the formation of lesions in a mouse-model of atherosclerosis.
In another, more recent study, young rats fed high fat/high cholesterol diets with rice or soy protein had improved insulin sensitivity as well as lower serum and liver cholesterol levels compared to casein-fed rats.
Plain, unflavored rice protein powder has a neutral, slightly sweet flavor that’s superior to soy. One downside, however, is that it has a “gritty” mouthfeel when dissolved in liquid. The quality and palatability are improving, however.
Both Axiom Foods and a newer company—Sun Warrior—have recently developed versions with a smooth mouthfeel and no grit. These improvements are a step in the right direction and should help make rice protein powders more appealing to the mainstream.
100% Rice Protein Isolate/Concentrate Products include: Nutribiotic Rice Protein (various flavors), MLO Brown Rice Protein, Sun Warrior Raw Vegan Organic Sprouted Rice Protein Powder, Swanson Oryzatein, Jarrow Brown Rice Protein Concentrate, Source Naturals Brown Rice Protein Powder and NOW Foods Rice Protein Powder
Rice protein concentrates are also used in blends with other vegetarian sources such as pea protein isolate. Pea protein is high in lysine, the limiting amino acid in rice, so a mixture provides a more complete amino acid profile.
Vegetarian Rice/Pea Protein Blends include: Olympian Labs Ultimate Greens Protein 8 in 1, Pure Advantage Vegan Complete Meal Replacement Protein Powder, Nature’s Way Alive Rice and Pea Protein Shake, NitroFusion Natural Multi-Source Protein Powder and LifeTime Life’s Basics Plant Protein