Not all Plant Proteins Are the Same

As plant-based eating rises in popularity, the variety of plant protein offerings seems to increase every day. However, not all plant proteins are the same, differing greatly in the quantity, quality, and variety of protein.

With plant-based protein powders, shakes, bars, and milk alternatives becoming readily available, it is important for consumers to learn how to differentiate between products and, for fitness enthusiasts, to pick one that maximizes muscle recovery and retention. A thorough search of the USDA nutrient database and NIH resources illustrate the complexities in navigating through the variety of products. Many of the protein powders available in the market are not represented on nutritional databases, and limited information about the products’ protein quality and quantity is publically available. Product labels and websites provide inadequate information and consumers have difficulty choosing what product is best. Most commercially available products are protein blends with a variety of plant and animal proteins, often not stating the proportion of proteins and potentially leading to consumption of low quality proteins. Low-quality proteins are incomplete proteins that are lacking in significant amounts of one or more essential amino acids.

Protein Powders

The variety of protein powders available on the market is almost as widespread as the varying amounts of protein per serving. Table 1 shows some of the commercial protein powders and the amount of protein they offer. For instance, Bob’s Red Mill soy protein powder contains 85 grams of protein per 100 grams of product, however, in Nutiva hemp protein powder, consumers only get 37 grams of protein per 100 grams of product.

Table 1: Commercial Protein powders and amount of protein in 100 grams of product

Protein Powder
(product used for comparison)
Grams of protein
per 100 grams
Soy Protein Powder (Bob’s Red Mill) 85g
Eggwhite Protein (NOW Foods Eggwhite Protein) 71g
Spirulina SUPPLEMENT powder (Nutrex Hawaii Hawaiian Spirulina Pacifica Powder) 67g
Pea Protein (Vega Protein & Greens, Vanilla) 67g
Brown Rice protein powder (Jarrow Formulas Brown Rice Protein, Sports Nutrition, Vanilla Flavor) 65g
Spirulina powder (Terrasoul Superfoods Spirulina Powder (Organic)) 57g
BetterBody Foods PB Fit Powder, Peanut Butter 42g
Hemp Protein Powder (Nutiva Organic Hemp Protein Hi Fiber) 37g

Adding to the consumer confusion, it is impossible to just compare labels to compare protein content because serving sizes also vary drastically. For Swanson organic soy powder, the serving size is 1 scoop, for Bob’s Red Mill soy protein powder, it is 1/2 cup, and for the Nutiva organic hemp protein, it is 1 tablespoon.

Protein Bars

The highest new product proliferation has come from bars – many of which are using plant-based proteins as their base. There is one for every taste bud – but between the snack bars, energy bars, meal replacement bars, raw bars and more, how do you compare the nutrients to find the best one? Table 2 shows the commercial bars available in market and the amount of protein in each vegan protein bar.

Table 2: Commercial protein bars and amount of protein in each bar

Vegan Protein Bars Type of Protein Grams of Protein Serving size Calories
GoMacro Organic Macrobar organic protein blend with brown rice protein and pea protein 11g 69g total 290
CLIF ENERGY BAR rolled oats, soy protein isolate, soybeans, soy flour 9g 68g total 230
CLIF BUILDER’S soy protein isolate, peanuts, rolled oats, soy protein concentrate 20g 68g total 280
L?rabar ALT dates, peanuts 10g 55g total 270
NuGo All-Natural Nutrition Bar soy protein isolate 11g 50g total 170
L?RABAR dates, peanuts 6g 45g total 220
Manitoba Harvest Hemp Heart Bar hemp hearts 10g 45g total 240
Simply Protein Bar soy protein isolate 15g 40g total 140
Health Warrior Chia Bar (snack bar) white chia seeds 3g 25g total 100

Large selection of plant-based milks at Trader JoesPlant-based Beverages

Whether a glass on its own or the base for a smoothie or shake, plant-based beverages offers different characteristics – but when it comes to protein, there is a very clear winner. Soymilk contains on average 7 or 8 grams of protein, while most plant-based milks only offer 1 gram. Some try to trick the consumer – Almond Plus has “5x Protein,” but five times 1 gram is still only 5 grams. Table 3 shows the commercial plant-based milk available in the market and the amount of protein in each cup.

Table 3: Commercial plant-based milk and amount of protein in 1 cup of product

Beverages (Milk) Grams of protein
per 1 cup
Soymilk (Silk Unsweetened) 7
Almondmilk+ (So Delicious Almond Plus, Unsweetened) 5
Hempmilk (Pacific Natural Foods) 3
Coconutmilk (Aroy-D) 1
Almondmilk (Silk, Unsweetened Vanilla) 1
Ricemilk (Dream, Original Unsweetened) less than 1
Cashewmilk (So Delicious, Unsweetened) 0

Protein Quality

As we’ve said, not all protein is created the same. You evaluate protein’s quality by looking at the “building blocks” of protein, or amino acids, making sure the foods you eat have the right balance of essential amino acids and seeing how well your body can digest and absorb them – this is relayed in the protein digestibility-corrected amino acid score (PDCAAS). A PDCAAS score of one indicates the highest value of protein digestibility and highest protein quality. See how different proteins stack up:

PDCAAS values for common proteins

While the PDCAAS value is a helpful chart that could help consumers navigate through the options, many commercial products available in market are protein blends and the labels fail to inform you of the amount and proportion of each type protein. All sources of plant protein found in bars and protein powders vary in their PDCAAS value and for many types of protein, there is limited information about the product’s protein quality. Just because a product uses a protein blend does not necessarily make it equivalent to a high quality protein, despite the way the product is marketed.

Furthermore, there is more research to be done to confirm whether protein blends are actually easy for the muscles to use. Instead, consumers should be informed about what we do know by research, which is that PDCAAS values determine the protein quality for humans – and soy protein concentrate has a PDCAAS value of 1. Studies show soy protein supports muscle growth and development and is also easily digestible, widely accessible, and sustainably produced. Soy has a high total protein, mid-level of leucine, and is a cost-efficient plant-based alternative to dairy or whey.

The Food and Drug Administration, the Dietary Guidelines for Americans, and the American Cancer Society have all agreed upon the safety of soyfoods, and even mentioned that soyfoods are low in saturated fat, high in complete protein, fiber and iron, they contain essential omega-3 fatty acids and are safe to eat.

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