The beneficial amino acid glycine was formerly used in the supplements industry to
products to "stretch". This put them in a bad light. The latest
Research shows, however, glycine is like a Swiss Army knife. It can be a true
miracle weapon for our musculoskeletal system, but even to our young-keeping
of our cells significantly.
What exactly we need it for, what the dangers of a deficiency are, and whether we need it
Supplement should, I would like to clarify with this article.
Collagen & Glycine - in a nutshell
With more than 30 % of the total mass of all proteins, collagen is the most abundant
occurring protein in our body. It is an important and essential component
of our connective tissue, i.e. tendons, ligaments, bones, cartilage and also teeth
or the skin. You can say collagen is the glue that holds everything together.
Collagen is hardly stretchable and has an enormous tensile strength. In the primary structure
of collagen shows that the amino acid glycine is located at every third position.
Through this, we begin to understand how important glycine is for collagen formation in the body.
So can support our musculoskeletal system.
Furthermore, glycine is also important for digestion and for various enzyme functions, but also
relevant for our immune system and even for nerve conduction.
That sounds like a broad and important spectrum!
Research found that production in the body may not be sufficient to cover all the
functions. About 8 - 10 g could be missing daily. Most studies on the
glycine supplementation, however, are animal studies and the few human studies
were mostly made with old or sick people. So as so often it is a little
too early to make a clear recommendation. But the signs are good for glycine
as a dietary supplement with a very interesting price-performance ratio.
Especially for athletes with regular high loads on joints etc. and
of course also people who already have a high wear.
But glycine has much more to it and even stands in the improvement of sleep and
also the focus of research in the aging process.
Here's a little biochemistry: how glycine is formed and why that may not be enough
Glycine accounts for about 11 % of all amino acids in the body - most of glycine (about 80
%) is used for protein formation. Many functions are attributed to glycine.
As already mentioned, glycine makes up every 3rd position in collagen, it is responsible for
the flexibility of binding sites of enzymes, formation of neurotransmitters, it regulates
Immune functions and it is used for the formation of hereditary material, creatine, serine and haem but
also needs antioxidants.
First, we take glycine through the diet from animal and vegetable
protein sources. Meat and fish have high amounts of glycine, and bone broth
is one of the superstars in terms of collagen and therefore glycine content. Yes exactly, the
overcooked bone must contain the marrow, only then the calculation works. A Maggie
Dice can not do that.
However, the daily intake accounts for only a small part of the requirement. In addition
the synthesis from serine, choline or betaine via sarcosine, the production at the L-carnitine
synthesis or from the formation from glyoxylates. The body appears about 12 - 15 mg
synthesize glycine per kilogram of body weight per hour, but the synthesis can also be
be somewhat lower when less protein is consumed. During the synthesis
production from serine seems to be the main pathway, other mechanisms can be
be neglected. Precisely this step in turn requires cofactors from vitamin B6
and vitamin B9 and in the process glycine and MTHF (methyltetrahydrofolate) are formed. So that the
synthesis can take place, it must also be possible to utilize both products. Exactly
this could be the cause of poor synthesis: a kind of bottleneck for the
During a biochemical investigation, Meléndez-Hevia and his team come to the
Conclusion that there is probably a deficit of about 8 - 10 g glycine daily in the body. (2)
A deficiency of glycine is probably not life-threatening, but could well affect the
Positively influence the aging process of the body.
Collagen & connective tissue
Glycine is thus essential for the formation of collagen and
thus connective tissue. These include cartilage, skin, bone tendons and ligaments. With the
regular renewal of these tissue types, for example for repair, or
simply in natural equilibrium, glycine can be recycled but unfortunately only to a
Part. With age, glycine is increasingly needed for renewal.
Research groups here have also seen in laboratory experiments or animal studies,
that glycine could increase collagen synthesis, or reduce arthritis.
Unfortunately, these are not yet human studies. In addition, glycine appears to stimulate the formation
of collagen degrading substances. (5-7)
Cell and animal experiments have also been carried out for muscle building. Thereby one has
found that glycine or its precursor serine are necessary for the
Population growth of muscle cells. Without glycine in the diet, fewer
Stem cells for muscle production formed. This is particularly relevant after
injuries, or even at an older age. Again, as mentioned, this is not a
Human studies and certainly not tested whether glycine has a performance enhancing
effect and could be used as a supplement. (8,9)
Oxidative stress and aging
It was already mentioned above that glycine is necessary for the formation of antioxidants.
be. Oxidants are produced throughout the body when energy is provided. Also the
Ingestion of harmful substances, for example alcohol or cigarette smoke
generates a particularly large number of oxidants. These can be thought of as activated molecules,
which particularly like to react with other substances and thus easily cause damage.
These oxidants must be deactivated and for this purpose the antioxidants are
responsible for preventing grosser damage and oxidative stress. Glutathione is the
most important antioxidant in our cells and glycine is needed for its formation. In a
Human study with old and young people has shown that older people are
have less glutathione in the body and this is probably due to a lower synthesis.
Supplementation with glycine has restored glutathione levels to those concentrations
increased, which occur in young people. This then also increased the oxidative stress
and the damage thereby decreases. (10) Also in current animal experiments it has been seen that
Glycine improves the glutathione status. Along the way, glycine reduces the release of
proinflammatory substances. (11)
Aging is not only attributed to oxidative stress. Subject of current
research is also a substance called homocysteine. It is an intermediate product in the
Formation of cysteine from methionine. Thus the conversion of a sulfur-containing
amino acid into another. While we need both amino acids for a healthy
metabolism, but the intermediate homocysteine is suspected of being a trigger of the
aging and trigger Alzheimer's disease, for example. Glycine is a prerequisite for a
enzyme, which breaks down excess methionine and thereby prevents the accumulation of
homocysteine is reduced. This theory is based on experiments that have found,
that glycine supplementation in animals and nematodes increases the lifespan
significantly prolonged. (12,13)
Metabolic syndrome and diabetes
A large part of the research is also concerned with the possible positive effect of
Glycine on diabetes or consequences of metabolic syndrome. The metabolic
Syndrome is a composite of several risk factors. These include high blood sugar
and blood pressure, a high abdominal circumference and poor blood lipid levels. At
When these factors come together, the risk of developing secondary diseases is high.
In a large human study of 74 diabetic patients, 15 g of glycine daily was able to
significantly improve long-term values (HbA1c) as well as reduce inflammatory mediators.
(14) In animal studies, glycine blocks the formation and action of proinflammatory
substances from the fatty tissue. It also improves insulin and sugar tolerance as well as
Fat levels and decreased oxidation products. (15-18) In general, patients with
diabetes or severe obesity to have low glycine levels, but it is still
unclear whether this is a consequence or a cause. (1,19)
Even though a lot is happening in terms of research here, there is unfortunately still a lack of sufficient studies
on people and especially on healthy individuals and athletes, in order to achieve general
to be able to make statements. In general, glycine is considered safe and therefore speaks
nothing against further research here and especially the theories of metabolic
eye of the needle (2,3) with practical experiments. Animal experiments and theoretical
Models from these give us important insights, but, as with much other research, are
But if this information is sufficient for you and you decide based on it
glycine, I recommend at least 10 - 12 g per day in a preferably
If you consume foods rich in collagen or glycine, please also pay attention to
make sure that your vitamin C intake is sufficient. Vitamin C is considered a strong co-factor
for the absorption of the desired substances.
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alterations in obesity and metabolic diseases. Nutrients [Internet]. 2019 Jun 1 [cited
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- Meléndez-Hevia E, De Paz-Lugo P, Cornish-Bowden A, Cárdenas ML. A weak link in
metabolism: the metabolic capacity for glycine biosynthesis does not satisfy the need
for collagen synthesis. J Biosci [Internet]. 2009 Dec 3 [cited 2021 Feb 3];34(6):853-72.
Available from: http://www.ias.ac.in/jbiosci
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