Collagen, the supplement for joint and skin health turns out to be anabolic too?
Sweet, but how potent?
Pretty potent alright…read on!
So it all started in 2015 when Zdzieblik conducted a study, where they gave men with sarcopenia 15g of collagen daily for 3 months.
The results were apparently so good that Phillips wrote a letter to the editor of the British Journal of Nutrition in 2016 just to say how great the results actually were. Here are a few snippets from that letter (R):
“We note that the 4·2 kg gain in FFM in the collagen peptide supplemented group is unrivalled by any study of protein supplementation in older resistance training sarcopenic men(2,3). One study, in which men with COPD received 100 mg of testosterone enanthate (injected weekly), comes close to the findings of Zdzieblik et al.(1), but in this study men receiving testosterone and performing resistance training gained only 3·3 kg of FFM and lost 1·1 kg of fat mass”
Do you see that? The collagen group got even better results than men on testosterone!
“Collagen peptide-supplemented subjects lost a reported 5·5 kg of fat mass. This loss of fat mass, in 12 weeks, is approximately 80 % of that seen in older men following a hypoenergetic diet (−3138 kJ/d) (−750 kcal/d) or −3·1 MJ/d) while exercising for 6 months”
The fat loss was so good, that the collagen group lost about 80% as much fat as men that were on a calorie restricted diet for 6 months in half as much time!
The big reason why collagen/gelatin was so underappreciated before was because it’s not a complete protein. It’s low in leucine (which potently promotes muscle protein synthesis) and the sulfur amino acids methionine and cysteine and devoid of tryptophan. It’s only high in the non-essential amino acids glycine, proline, hydroxyproline and it’s got a tad of the essential amino acid arginine, although this little bit of extra arginine won’t boost hypertrophy. With this in mind, because it lacks those essential amino acids, it would never work to boost muscle growth.
However, what researchers also recently found, was that, on a low protein diet, gelatin was actually better at maintaining a positive nitrogen and retaining muscle mass whey on a low protein diet.
Here’s a quote from the paper (R):
“Collagen is generally regarded as having a relatively low biological value, mainly due to the low amount of BCAA and lysine (Table 1). Nevertheless, the mixture of amino acids has been shown to be superior compared with whey protein in maintaining N balance and body weight during a low-protein diet.”
“The effect was significantly more pronounced in subjects receiving collagen peptides: FFM (TG (treatment group) +4·2 (sd 2·31) kg/PG (placebo group) +2·9 (sd 1·84) kg; P<0·05); IQS (Isokinetic quadriceps strength) (TG +16·5 (sd 12·9) Nm/PG +7·3 (sd 13·2) Nm; P<0·05); and FM (TG -5·4 (sd 3·17) kg/PG -3·5 (sd 2·16) kg; P<0·05).” (R)
“After 12 weeks of the trial, the percentage of body fat and body fat mass (kg) in IG (intervention group) were found to be significantly better than those of subjects in CG (control group) (-1.2% vs. 2.7%, p = 0.024 and -1.2 kg vs. 0.3 kg, p = 0.025).” (R)
Time after time it shows that people that consume collagen/gelatin grow more muscle, have less fat and gain more strength, especially the explosive kind of strength (R).
So how much should you or could you consume each day?
Meléendez-Hevia et al. estimated that endogenous synthesis of glycine in healthy humans can satisfy at most only 30% of the metabolic needs for the synthesis of proteins (e.g. collagens). Similarly, humans, young or adult, cannot synthesize a sufficient quantity of proline to repair wound tissues (R). That’s why glycine is starting to be considered as conditionally essential. Only under certain conditions does it become essential to consume. Well, I think it should be unconditionally essential because if you don’t consume it you’re always in a negative glycine balance.
A recent study determined that up to 36% collagen peptides can be used as a protein substitute while still maintaining the indispensable amino acid balance and the high protein quality score of the standard American diet (PDCAAS equals to 1.0). As the amount went up, the first limiting amino acids were the sum of the sulfur-containing amino acids methionine and cysteine.
The PDCAAS calculations further revealed that the maximum proportion of collagen peptides that could be incorporated in the standard American diet is 54% while maintaining good dietary protein quality (PDCAAS equals to 0.75). In this case, the first limiting indispensable amino acid was tryptophan (R).
That means that you can almost consume up to 50% of your total daily protein from collagen/gelatin and still maintain a “good” or “high” dietary protein quality (PDCAAS equals 0.75–1.0). An additional benefit of this substitution may be derived not only from the increased dietary content of glycine, proline and hydroxyproline, all major components of body collagens, which in turn represent 25–30% of total body proteins, but also from consuming lower amounts of the inflammatory sulfur amino acids and the metabolic toxin, tryptophan. Tryptophan, the precursor to serotonin, slows down the metabolic rate, lowers thyroid function, inhibits steroidogenesis, and boosts serotonin synthesis significantly. If you don’t know about the negative effects of serotonin yet, please read this article.
So my recommendation would be, if you were to go full gelatin mode, would be to consume about 75g of regular good quality animal protein, and then an additional 75g of gelatin. If you want to keep it more moderate, eat 100g of good quality animal protein and only 50g of gelatin. But if that is still too much for your taste, 15g daily should also suffice according to the studies.
Now that collagen/gelatin has been proven to be anabolic and anti-obesity, the researchers still don’t really know how.
Let’s speculate on what we do know:
- An excess of methionine can actually suppress growth, and this is reverse by glycine (R).
- An excess of methionine also deposits iron in soft tissue, such as the spleen, and causes anaemia and only glycine can prevent this (R).
- Glycine potently inhibits proteolysis (muscle breakdown) and lowers cortisol (R). Research shows that muscle growth is enhanced to a much greater extent with an anti-catabolic compound (cortisol antagonist) than a purely anabolic compound (androgen receptor agonist).
- Glycine activates Akt/mTOR pathway directly, which promotes muscle protein synthesis (R).
- Hydroxyprolyl-glycine, a collagen derived dipeptide, promotes hypertrophy through the PI3K/Akt/mTOR pathway (R).
- Gelatin improves insulin sensitivity and secretion (R). Insulin is highly anabolic and when the body is resistant to it, it loses that anabolic and anti-catabolic benefit.
- Glycine increases GLUT4, thus increasing glucose uptake into the muscles and speeds up muscle glycogen resynthesis. Full muscle glycogen creates an anabolic environment.
- Glycine restores the anabolic effect of leucine in the body. This insensitivity and reduced anabolic effect are caused by endotoxins (glycine is a TLR4 antagonist) and inflammation (glycine lowers inflammation potently) (R).
- Glycine enhances water, ion, and amino acid transport all of which can promote anabolism.
- Gelatin potently lowers inflammation, and inflammation promotes anabolic resistance, fat gain, insulin resistance, ageing, metabolic syndrome, etc.
- Gelatin increases AMPK and adiponectin, which improves insulin sensitivity, increase the oxidation of glucose and fat, reduces fat synthesis (lipogenesis), increases mitochondrial biogenesis, quality and function as well as energy production (increases state IV respiration) and thermogenic potential (R, R, R).
- Gelatin improves liver function by reducing lipogenesis and fat accumulation in the liver and increasing fat uptake in the adipose tissue. It decreases PPARγ in the liver and increases it in the adipose tissue (R).
- Gelatin reduces gut permeability and circulating endotoxins and also inhibits the activity of kupffer cells, thus lowering oxidative stress, inflammation and improving liver function (R).
- Collagen peptides positively influence microcirculation; therefore, this might cause an additional beneficial effect in promoting muscle growth compared with other protein sources (R).
- Gelatin increases IGF-1 (R).
- Gelatin speeds up recovery and restoring muscle activation and power output by enhancing extracellular matrix remodelling and repair and muscle function (R).
Collagen/gelatin are so much more important than just aiding in muscle growth or keeping you lean, but also has significant health-promoting properties and this would really be one of the most important additions to your diet.