If you do any form of resistance training, your protein needs are greater than those of a sedentary person. That additional protein goes towards muscle repair and to provide the building blocks for muscle hypertrophy. The best way to get that protein is from food sources, but for convenience, some people supplement with a dairy-based protein powder like whey. When you’re in a rush and don’t have time to eat a full recovery snack, whey protein in a smoothie does the job.
When you think of protein, visions of meat and dairy probably come to mind first, but there’s a growing interest in plant-based sources of protein. Are they as effective for building muscle as animal protein sources?
How Plant and Animal Protein Differ
Both plant and animal proteins are made up of protein building blocks called amino acids. The difference is animal protein imparts all of the essential amino acids your body needs to build muscle. Certain amino acids are called “essential” because you don’t have the enzymes necessary to synthesize them and must get them through diet. The only plant protein source that has all the essential amino acids in sufficient amounts is soy. This makes soy-based foods like tempeh, tofu and soy protein supplements a “complete” protein.
How is the protein in plants different? Plant-based sources of protein are missing one or more essential amino acids. Fortunately, you can make up for these missing components by eating a variety of plant protein sources. For example, whole grains have an essential amino acid that legumes lack and vice versa. The key to getting all of the essential amino acids on a plant diet is to vary the plant foods you eat.
Is Animal Protein Superior to Plant-Based Protein for Muscle Growth?
A 2013 study compared rice protein to whey protein for muscle growth in response to resistance training. One group of 24 college students consumed either 48 grams of whey protein or 48 grams of rice protein after their three times weekly resistance training sessions. At the end of 8 weeks, they compared the two groups. Both groups experienced similar increases in muscle size, power, and strength as well as a decrease in body fat. There were no significant differences in recovery times or soreness. At least in this study, which was double-blinded, rice protein was as beneficial as whey protein for supporting muscle growth.
Before throwing out the whey, keep in mind this is only one study. A number of studies comparing whey protein to another plant protein, soy, show whey is superior for boosting muscle protein synthesis and muscle growth. One advantage whey has over plant protein sources is it’s richer in branched-chain amino acids (BCAA). BCAA are “superstars” when it comes to muscle growth. One BCAA, leucine, serves as a signaling molecule to turn on muscle protein synthesis in skeletal muscle tissue.
Leucine also helps keep your body in an anabolic state and has favorable effects on insulin sensitivity. Not that plant-based protein sources don’t have some BCAA, for example, rice protein contains branched-chain amino acids like whey, but in lower amounts. You could get the BCAA benefits of whey by consuming rice protein, but you’ll need to consume more.
Is Pea Protein a Good Alternative?
Pea protein is also high in BCAA. If you use a protein supplement in your smoothies and are allergic to dairy, pea protein is a good substitute for animal protein supplements since it’s easy to digest and contains substantial quantities of BCAA. Plus, pea protein is gluten-free and non-GMO. It’s also an option if you eat a vegan diet, especially if you have problems getting adequate protein from whole foods. Don’t forget you can also mix blend plant-based proteins to create an optimal amino acid profile.
Digestibility and Absorption
An advantage of whey protein is it’s rapidly digested and absorbed, making it an ideal addition to a post-workout shake. Be sure to consume protein in combination with carbohydrates to maximize muscle recovery and growth. Casein, another dairy protein, and soy are both absorbed more slowly than whey, as are most plant proteins, although pea protein is taken up fairly quickly. Some, but not all, research shows there’s an “anabolic window” 20 to 60 minutes after a resistance training workout where your body can best utilize protein for muscle growth and repair. Some studies show the anabolic window may be substantially longer – up to 6 hours.
The Bottom Line
Animal proteins have the advantage of offering a complete source of essential amino acids and being higher in branched-chain amino acids like leucine than plant proteins, but you can compensate for this by eating a variety of plant-based protein sources and taking in more total protein. If you use a protein powder post-workout and want a plant-based source, pea protein is a good option since it’s absorbed fairly rapidly, although not as quickly as whey.
If you use a dairy or plant-based protein supplement occasionally for convenience, that’s okay, but it’s not necessary. Whole food sources of protein like eggs, fish, poultry and organic dairy, as well as plant-based protein sources like tempeh, tofu, legumes, whole grains, and nuts, supply the protein your muscles need for growth naturally. Protein powders, both dairy and plant-based, may contain added sugar, fillers, and even heavy metals. If you use one, buy it from a reputable company.
References:
PR Newswire. “First Double Blind Study Proves Plant-based Rice Protein Has Identical Benefits To Animal-based Whey Protein”
J Am Coll Nutr. 2013;32(2):122-35. doi: 10.1080/07315724.2013.793580.
J. Nutr. January 2006 vol. 136 no. 1 227S-231S.
Nutritional Outlook. “Plant Protein versus Dairy Protein for Muscle Building”
Med. Sci.Sports Exerc., Vol. 38, No. 11, pp. 1918-1925, 2006.
Journal of the International Society of Sports Nutrition 2013. 10:53. doi:10.1186/1550-2783-10-53.
J Nutr Biochem. 2013 Jul;24(7):1285-94. doi: 10.1016/j.jnutbio.2012.10.004. Epub 2013 Jan 14.
PLOS One. “Dietary Leucine – An Environmental Modifier of Insulin Resistance Acting on Multiple Levels of Metabolism” June 22, 2011.
Nutr J. 2013; 12: 86.
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