How to Make Your Vegan Protein More Anabolic
by: Robbie Durand
Skeletal muscle mass is regulated via changes in both muscle protein synthesis and muscle protein breakdown. The digestibility of the protein source is defined as the proportion of dietary protein–derived amino acids that is digested and absorbed, thus becoming available in a form suitable for body protein synthesis. It’s been well established that increases in BCAA can not only increase muscle recuperation but may also enhance muscle mass and fat loss. Most bodybuilders will often recommend a high-quality whey protein powder, but if you’re a vegan bodybuilder than your protein choices are limited. In general, it appears that plant-based vegan protein sources may exhibit lower digestibility than animal-based proteins. Animal-based protein sources, including dairy, eggs, and meat, are highly digestible (>90%). Plant-based sources such as maize, oat, bean, pea, and potato tend to exhibit lower digestibility than do animal-based sources, with values ranging from 45% to 80%. The lysine and methionine contents are lower in plant- based proteins than in animal-based proteins.
Recently, soy protein popularity has increased due to its use in health food products. Soy protein is regarded as being concentrated in protein bodies, which are estimated to contain at least 60–70% of the total soybean protein. Soybeans also contain biologically active or metabolic proteins, such as enzymes, trypsin inhibitors, hemagglutinins, and cysteine proteases very similar to papain. Soy protein contains phytoestrogens, which bind to estrogen receptors in the body. Studies assessing the postprandial muscle protein synthesis response to soy protein ingestion have shown that the ingestion of amounts ranging from 17.5 to 40 g soy protein does not increase muscle protein synthesis to the same extent as the ingestion of whey protein, skimmed milk, or beef, both in resting and postexercise conditions.
Controversy exists whether soy will support skeletal muscle protein accretion in response to resistance training as efficiently as whey or casein protein. Previous research has reported that whey was superior to soy in stimulating amino acid uptake during a resistance-training program. However, other studies have shown no differences in whey vs. soy protein regarding strength and body composition gains. Soy has a beneficial impact on reducing serum lipids, but the effect on strength and body composition benefits remain controversial, so researchers wanted to examine its impact on elderly adults. Maintenance of muscle mass and strength into older age is critical to maintaining health. The researchers wanted to determine whether increased dairy or soy protein intake combined with resistance training enhanced strength gains in older adults. 179 healthy older adults, with an average age of 61 years of age performed resistance training three times per week for 12 weeks and were randomized to one of three dietary treatments.
• high dairy protein (HP-D, >1.2 g of protein/kg body weight/d; ∼27 g/d dairy protein).
• high soy vegan protein (HP–S, >1.2 g of protein/kg body weight/d; ∼27 g/d soy protein)
• usual protein intake (UP, <1.2 g of protein/kg body weight/d).
Muscle strength, body composition, physical function and quality of life were assessed at baseline and 12 weeks. Protein intake was higher in high dairy protein and high protein soy diet compared with a usual protein diet. Strength increased less in high protein soy diet compared with high dairy protein and typical protein diet. All groups increased lean mass, physical function, and mental health scores increased, and fat mass decreased with no differences among the groups. Increased soy protein intake reduced gains in muscle strength during resistance training in older adults compared with increased intake of dairy protein or usual protein intake. This shows that the lack of BCAA’s, in particular, leucine, in soy could be a limiting factor for the reduced muscle gains in the soy group.Leucine: The Key Regulator of Muscle Building
It is now generally believed that the leucine content of a protein source is a significant and independent predictor of its capacity to stimulate postprandial muscle protein synthesis. Furthermore, the highest level of leucine levels and stimulation of muscle protein synthesis was observed after the ingestion of whey protein. Comparison of the different protein sources reveals that the leucine content of whey is highest, with 13.6%. minimal-based protein sources contain more leucine than do plant- based proteins. Most plant-based vegan protein sources have a leucine content of; 6–8%, whereas animal-based protein sources tend to have a leucine content in the range of 8.5–9% and >10% in the case of dairy proteins. The higher leucine content may be a critical factor responsible for the proposed greater capacity of animal-based proteins to stimulate postprandial muscle protein synthesis rates when compared with the ingestion of various plant-based proteins. Given the lower leucine contents of plant-based protein sources, substantial amounts (>40 g) of a plant-based protein source should theoretically be ingested to maximize post shake muscle protein synthesis rates. If you’re a vegan bodybuilder, consider taking a unflavored BCAA powder or a leucine powder that you can add to your vegan protein shakes; it will boost its anabolic activity. BCAA’s are rich in leucine which will enhance the anabolic actions similar to that of a high-quality whey protein powder.