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SILK AMINO ACIDS

Q: Does silk amino acid supplementation improve athletic performance?

Limited evidence suggests modest improvement in aerobic stamina in elite swimmers after short-term supplementation combined with training, but more research is needed.

Q: Is it safe to take silk amino acids daily?

Available data indicate safety in short-term use at studied doses, but long-term safety and effects are currently unknown due to limited research.

Q: How soon can benefits be expected?

Improvements in aerobic stamina were observed after 12 days of supplementation in one study involving elite athletes.

Q: Are silk amino acids better than other amino acid supplements?

No comparative studies exist. Other amino acid supplements like BCAAs have more extensive evidence for muscle recovery, but they differ in amino acid profile.

Q: Can silk amino acids cause muscle damage?

An increase in creatine phosphokinase was observed, possibly reflecting increased training load rather than direct toxicity from the supplement itself.

Also known as: Silk amino acids, silk peptide hydrolysate, silk protein hydrolysate, Silk Amino Acids

Overview

Silk amino acids (SAA) are hydrolyzed peptides primarily derived from the fibroin and sericin proteins of *Bombyx mori* (silkworm) silk. They consist mainly of glycine, alanine, and serine, which are characteristic amino acids of silk fibroin. Obtained by enzymatic or acid hydrolysis of silkworm cocoons, SAA provide a mixture of free amino acids and small peptides. They are marketed as a dietary supplement to enhance stamina, muscle recovery, skin hydration, and hair health, and are also explored in sports nutrition for endurance. SAA are rich in specific amino acids, highly bioavailable due to their small peptide size, and may influence collagen synthesis and antioxidant status. Research on SAA as a supplement is limited, with mostly small randomized controlled trials (RCTs) and animal studies, and no large-scale systematic reviews or meta-analyses specifically confirming their efficacy.

Benefits

Limited evidence suggests that silk amino acid supplementation may offer benefits primarily for elite athletes. A randomized controlled trial (RCT) involving elite male fin-swimmers demonstrated that 12-day supplementation with 500 mg/kg/day of silk amino acids improved aerobic stamina. This was evidenced by a statistically significant positive shift in swimming velocity at a lactate concentration of 4 mmol/L (an increase of 0.05 m/s) and a sevenfold smaller increase in serum lactic acid compared to controls (p < 0.05). This indicates improved endurance and reduced lactic acid accumulation during intense exercise. The study also noted a non-significant increase in serum testosterone and an increase in creatine phosphokinase, suggesting some muscle stress associated with intense training. These benefits have only been observed in elite athletes under rigorous training conditions, and there is no data for the general population or other groups. The effect sizes are modest and limited to short-term use, with benefits observed after 12 days of supplementation combined with training.

How it works

Silk amino acids are believed to exert their effects primarily through the provision of readily available amino acids and small peptides that support muscle metabolism and potentially antioxidant defense. As hydrolyzed forms, they are rapidly absorbed in the gut, making their constituent amino acids quickly available to the body. During exercise, SAA may help reduce lactic acid accumulation, thereby improving endurance. The specific amino acid profile, rich in glycine, alanine, and serine, likely contributes to these metabolic effects. While no direct molecular targets have been identified, their impact is thought to be mediated by general amino acid availability and modulation of metabolic pathways, supporting energy production and recovery processes.

Side effects

Silk amino acids are generally considered safe at the doses studied in human trials, with no serious adverse events reported. Common side effects (occurring in >5% of users) have not been clearly reported. Uncommon side effects (1-5%) include an increase in creatine phosphokinase (CPK), which indicates muscle stress or damage. However, this observation in the sole human RCT was likely attributable to the intensified training regimen undertaken by the elite athletes rather than a direct toxic effect of the supplement itself. Rare side effects (<1%) have not been documented. There are no documented drug interactions or established contraindications for silk amino acids. Safety data for special populations, such as pregnant women, children, or individuals with pre-existing medical conditions, are currently unavailable, and caution is advised in these groups.

Dosage

The minimum effective dose identified in the sole human randomized controlled trial (RCT) was 500 mg/kg/day. This dosage was administered to elite athletes. The optimal dosage range for silk amino acids is currently unknown, as this is the only RCT that has investigated a specific dose. The maximum safe dose has also not been established. In the study, the supplement was administered three times daily, 30 minutes before training sessions. Silk amino acids are typically provided as a hydrolyzed powder, which was dissolved in a carbohydrate drink in the study. The hydrolyzed form enhances absorption, and co-ingestion with carbohydrates may further improve uptake. No specific cofactors are identified as required for their efficacy.

FAQs

Does silk amino acid supplementation improve athletic performance?

Limited evidence suggests modest improvement in aerobic stamina in elite swimmers after short-term supplementation combined with training, but more research is needed.

Is it safe to take silk amino acids daily?

Available data indicate safety in short-term use at studied doses, but long-term safety and effects are currently unknown due to limited research.

How soon can benefits be expected?

Improvements in aerobic stamina were observed after 12 days of supplementation in one study involving elite athletes.

Are silk amino acids better than other amino acid supplements?

No comparative studies exist. Other amino acid supplements like BCAAs have more extensive evidence for muscle recovery, but they differ in amino acid profile.

Can silk amino acids cause muscle damage?

An increase in creatine phosphokinase was observed, possibly reflecting increased training load rather than direct toxicity from the supplement itself.

Research Sources

https://pmc.ncbi.nlm.nih.gov/articles/PMC4269914/ – This randomized controlled trial investigated the effects of silk amino acid supplementation on aerobic stamina in elite fin-swimmers. The study found that 12 days of supplementation significantly improved swimming velocity at a specific lactate concentration and reduced lactic acid accumulation, suggesting enhanced endurance. It also noted an increase in creatine phosphokinase, possibly due to intensified training.
https://pmc.ncbi.nlm.nih.gov/articles/PMC7536055/ – This meta-analysis focused on the properties of spider silk, providing insights into the amino acid composition of silk proteins. While it offers valuable information on the material science of silk, it does not directly address the clinical relevance or efficacy of silk amino acids as a human dietary supplement.
https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0109141 – This systematic review and meta-analysis examined the effects of general protein and amino acid supplementation on lean body mass and strength. While it supports the benefits of protein/amino acid intake for muscle development, it does not contain specific data or findings related to silk amino acids, thus not directly supporting their unique efficacy.