Pea and soy proteins are the biggest players within the vegan protein market. Together, they make up the majority of vegan frozen foods, meats, shakes, and protein powders. Recently, many other vegan products have been coming out that contain other sources of protein like rice, flax, pumpkin, and hemp. Most of the time, these protein sources are combined with pea protein to create a product that has a complete amino acid profile—or a product that contains all the amino acids (building blocks) the body needs to function optimally. Other times, these protein sources are placed in a product by itself, where its many benefits are allowed to shine. Let’s take a look at some of the more popular alternative vegan protein sources.
Rice Protein
Also known as brown rice protein or sprouted rice protein, rice protein is made from rice and is allergen-free, non-GMO, and can be organically sourced. The major benefit of rice protein is its amino acid profile. Rice protein contains an abundance of cysteine and methionine—two amino acids that pea protein lacks in effective amounts. When pea and rice proteins are combined together, they complement each other and form a combined protein source that is nutritionally complete (i.e., has all essential amino acids in the amounts that the body needs).
Despite the complementary amino acid profile, rice protein has some negatives. First, it is extremely gritty tasting. While all vegan proteins have a distinctive taste and texture, rice protein is especially bad as (on its own) it has a texture similar to sandpaper. However, when it is combined with pea protein the bad tasting texture is mitigated by pea protein’s creamy texture. Second, rice protein contains a high amount of arsenic, a heavy metal naturally present in the soil. All rice containing food products (including protein), uptake more arsenic from the soil than other grains. Although most arsenic is non-toxic (also called “organic arsenic”), some is not. This arsenic (also called “inorganic arsenic”) is found in ground water and soil as a result of industrial processing. Due to rice’s growing conditions, both inorganic and organic arsenic are absorbed into the plant and passed into the food supply by any rice product (rice protein, syrup, flour, grain, etc.). The high amount of arsenic in rice is independent of the organic status; organically grown rice absorbs organic and inorganic arsenic just as well as non-organic rice.
Flax Protein
Flaxseed oil has been increasing in popularity due to its high Omega-3 fatty acid content (good/healthy fats), which has been studied to improve heart and skin health. Flax seed protein is created as a by-product of flaxseed oil production. It has about a 35% protein content (one of the lowest of all vegan protein sources) but retains many of the nutrients that make flaxseeds so popular. Flax seed protein is high in dietary fiber (which, when combined with protein, makes a person feel full for longer), Omega-3 fatty acids (which has been studied to improve heart and skin health), and good amounts of other vitamins and minerals.
Although flaxseed protein is allergen-free, it does have a high amount of the same type of plant compounds that are in soy. These plant compounds (also known as phytoestrogens) weakly imitate estrogen in the body, which can either be desirable or not, depending on the person and their individual health conditions.
Like other vegan proteins, flax protein is deficient in one essential amino acid—lysine. Thankfully, pea protein contains an abundance of lysine. So, flax and pea proteins are typically combined together to form a complete amino acid profile.
Where have you seen rice and flax proteins?