The Power of Glycine: The Multifaceted Longevity Amino Acid
Glycine. Longevity. Amino Acid. Metabolic Health.
While scrolling through instagram earlier today a post popped up about Glycine comparing it to whey protein as a supplement for women. I’d heard of glycine before and its nickname “the longevity amino acid”. It actually is the smallest possible amino acid of the 20 that are essential for human life. It’s also a non-essential amino acid, which simply means our bodies cannot produce it naturally.
Fun fact: its name comes from the Greek word γλυκύς (glykys) which means sweet.
It was first discovered when hydrolysing gelatin, which in case you didn’t know contains collagen. In my post All About Collagen, I talk about this protein and how it’s made up of 19 amino acids, one of which is Glycine. Actually around a third of collagen is made up of glycine. So if you consume collagen, you’re already taking in glycine too. Other foods containing it are meat, fish, dairy, and some legumes.
Biologically glycine is a neurotransmitter of the central nervous system, and has multiple roles. For example it act as an antioxidant, is anti-inflammatory, and cryoprotective (protection of the cells). But let’s dive in even further into its roles.
The Multifaceted Roles of Glycine
1. Collagen Production and Skin Health
As glycine is a major component of collagen, actually around a third of its amino acid composition, the benefits of collagen come with glycine too. As we age, collagen production declines, leading to wrinkles and sagging skin. Ensuring adequate glycine intake can help mitigate these effects by supporting collagen synthesis.
2. Joint and Bone Health
Another role of glycine is that it’s integral to the formation of collagen in bones and joints, which provides strength and flexibility. Studies have shown that glycine supplementation can improve joint pain and mobility in individuals with osteoarthritis. Moreover, glycine’s role in collagen formation aids in maintaining bone density, crucial for preventing conditions like osteoporosis and osteoarthritis. 1
3. Sleep Quality
Glycine has been shown to improve sleep quality. It’s sleep promoting and has hypothermic effects, i.e., reducing core body temperature, which helps induce sleep.2
4. Cognitive Function
Glycine acts as a co-agonist at the NMDA receptor, which is crucial for learning and memory. Studies suggest that it may also enhance neuroplasticity and cognitive function.3 In animal experiment, consumption of it led to improved memory and behavioural changes.4
5. Metabolic Health
Glycine has several benefits on our metabolic health, which can help manage and even prevent metabolic disorders. Patients with type 2 diabetes were found to have lower levels of glycine.5 A review concluded that glycine supplementation improved various components of metabolic syndrome, e.g., diabetes, obesity, hypertension, and hyperlipidemia. 6
6. Lifespan Extension
Glycine supplementation has been shown to significantly prolong the lifespan of Caenorhabditis elegans (an organism used in ageing studies). This effect is linked to glycine's role in the methionine cycle, which is crucial for regulating gene expression associated with ageing. 7 In animals studies it has extended lifespan by around 30%.
7. Fertility
Glycine plays a crucial role in foetal development, as well as the embryonic development, as it reduced apoptosis in blastocysts.8 It also offers protection to the male reproductive system against lead toxicity.9
Evidently, glycine has various different effects across our body. Glycine might not be as well-known, but its impact on our health is profound. From supporting skin and joint health to improving sleep and cognitive function, glycine is a versatile nutrient that deserves more attention. Whether through dietary sources or supplements, ensuring you get enough glycine can be a simple yet effective way to enhance your overall well-being. If you want to try and experiment with its effect, try having your collagen in the evening and see if there is any improvement in your sleep! If you wish to simply supplement with glycine, that is also possible and also not very expensive.
Feel free to share your thoughts and experiences with glycine in the comments below. Have you noticed any changes since incorporating it into your diet? I’d love to hear your stories!
I hope you enjoyed, and thank you for taking some time out of your day to read to my post! See you next week! :)
Last week’s post:
Other posts you might like / mentioned:
Lee et al. Protective Effects of Glycine soja Leaf and Stem Extract against Chondrocyte Inflammation and Osteoarthritis. Int. J. Mol. Sci. (2023). https://doi.org/10.3390/ijms24054829
Kawai et al. The Sleep-Promoting and Hypothermic Effects of Glycine are Mediated by NMDA Receptors in the Suprachiasmatic Nucleus. Neuropsychopharmacol (2015). https://doi.org/10.1038/npp.2014.326
Peyrovian et al. The glycine site of NMDA receptors: A target for cognitive enhancement in psychiatric disorders. Progress in Neuro-psychopharmacology & Biological Psychiatry (2019). https://doi.org/10.1016/j.pnpbp.2019.02.001.
Imtiaz et al. Effect of glycine: Studying memory and behavioral changes in mice. Pakistan journal of pharmaceutical sciences (2018).
Alves et al. Glycine Metabolism and Its Alterations in Obesity and Metabolic Diseases. Nutrients (2019). https://doi.org/10.3390/nu11061356
Imenshahidi et al. Effects of glycine on metabolic syndrome components: a review. Journal of Endocrinological Investigation (2022) https://doi.org/10.1007/s40618-021-01720-3
Liu et al. Glycine promotes longevity in caenorhabditis elegans in a methionine cycle-dependent fashion. PLOS Genetics (2019) https://doi.org/10.1371/journal.pgen.1007633
Rasmussen et al. Glycine, a Dispensable Amino Acid, Is Conditionally Indispensable in Late Stages of Human Pregnancy.. The Journal of nutrition (2020). https://doi.org/10.1093/jn/nxaa263.
Ommati et al. Glycine protects the male reproductive system against lead toxicity via alleviating oxidative stress, preventing sperm mitochondrial impairment, improving kinematics of sperm, and blunting the downregulation of enzymes involved in the steroidogenesis. Environmental toxicology (2022). https://doi.org/10.1002/tox.23654
Thank you for sharing this Sara, been taking collagen did not know glycine has so many benefits.
Absolutely love this! I've been taking glycine nightly post sauna and have been waking up to incredible skin and amazing sleep scores. Thank you for this foundational article!