Collagen — provides structural support and strength to tissues1,2,3 —Accounts for about 30% of the total protein in the body. 28 percent collagenwhich is composed of the amino acid glycine.Four
glycine, proline, hydroxyprolineFive Glycine is a raw material for connective tissue, but its benefits go far beyond connective tissue health. In fact, a growing body of research suggests that glycine may play an important role in the aging process.
The body produces glycine, but endogenous production decreases with age. If you eat only red meat and little or no foods made from collagen-rich connective tissue, you may not be getting enough glycine in your diet either. The graph below details the amino acid ratio between gelatin/collagen and red meat (beef). As you can see, gelatin/collagen contains much more glycine than beef.
![amino acid](https://media.mercola.com/ImageServer/public/2023/September/amino-acids.jpg)
![amino acid](https://media.mercola.com/ImageServer/public/2023/September/amino-acids.jpg)
Glycine has many anti-aging effects
Glycine has been shown to extend lifespan in worms, mice, and rats and improve health in mammalian models of age-related diseases.6 In some animal studies, eating a diet containing 8% to 12% glycine increased median lifespan by as much as 28.4%.7
As Sim Rand, author of Metabolic Autophagy: Practice Intermittent Fasting and Resistance Training to Build Muscle and Promote Longevity, explains in the video above, glycine autophagy (a „self-eating“ process in which the body digests damaged cells), mimicking the longevity benefits of methionine restriction.8 Both of these effects are associated with an enzyme called glycine N-methyltransferase (GNMT).
Glycine is a receptor for GNMT, which converts glycine to sarcosine, a metabolite that induces autophagy. GNMT also plays a role in methionine clearance.9 Methionine is involved in cancer cell growth and metabolism, and restricting methionine has been shown to have the following effects:Ten
- Inhibits cancer cell growth
- extend lifespan
- Decreased levels of insulin, glucose, and insulin-like growth factor 1 (IGF-1)
- Reduces liver damage after exposure to dangerous amounts of acetaminophen
- reduce frailty
Intermittent methionine restriction alone has benefits such as improving glucose homeostasis, reducing obesity, and protecting against fatty liver disease.11 Glycine is also a precursor to glutathione, a powerful endogenous antioxidant that decreases with age.
Glutathione deficiency in older adults may be a contributing factor to the oxidative stress and mitochondrial dysfunction that causes age-related degeneration.Glycine also functions as a neurotransmitter12 and may play an important role in depression.13 It has also been shown to reduce neuroinflammation and protect against cognitive impairment in neurodegenerative mice.14
Glycine reverses aging in human cells
According to previous research,15 Glycine may also be involved in epigenetic regulation that promotes the entire aging process. As reported by Science Daily in 2015,16 Contrary to popular belief, the mitochondrial aging process may not be controlled by DNA mutations after all, but rather by epigenetic regulation.
This epigenetic regulation appears to be governed by two genes (CGAT and SHMT2) that control glycine production within mitochondria. By altering the regulation of these genes, the researchers were able to induce defects and restore mitochondrial function in human fibroblast cell lines.
Remarkably, simply adding glycine to a culture of fibroblasts taken from a 97-year-old person restored the respiratory function of the cells, suggesting that glycine treatment may reduce age-related respiratory disorders in fibroblasts from elderly people. „This suggests that it is possible to recover.“ Glycine supplementation may therefore give older people a „new lease on life.“
Glycine is necessary for daily collagen metabolism
Glycine makes up 28% of the body's collagen and is of course also required for optimal collagen synthesis. As Land explains in the featured video:17
“Glycine plays a very important role in direct anti-aging by reducing wrinkles and aiding collagen synthesis…The lower the intake of collagen and glycine, the slower the turnover of collagen.
Slow collagen turnover increases damage to collagen, such as glycation and oxidation, and reduces collagen deposition in tissues.
Collagen…makes up hair, teeth, skin, nails, organs, arteries, cartilage, bones, tendons, and ligaments. Collagen is literally the glue that holds you together. Therefore, ensuring the preservation of collagen is very important to slow down the progression of aging, especially wrinkles.
Starting at the age of 20, less than 10% of the collagen content of the skin is lost every 10 years. This means that by the age of 75, your skin will have lost 50% of its collagen content…
(U)p Until recently, it was thought that collagen turnover was very slow and only occurred over many years, or a lifetime. However, it has recently been discovered that university attrition occurs every day and is part of daily protein turnover. ”
Glycine prevents age-related diseases
Glycine also helps reduce chronic disease and disability, thereby extending your healthy lifespan. As reported in a 2023 scientific review, glycine has been shown to:18
Suppresses tumor growth in melanoma mice19 |
Reduces fasting blood glucose, insulin, triglycerides, and IGF-1 in male rats20 |
Preserves muscle mass and reduces inflammatory markers in mice with cancer cachexiatwenty one |
Improving endothelial function in aged ratstwenty two |
Reduce weight gain and improve bone density in mouse model designed to mimic postmenopausal bone losstwenty three |
prevent cardiac hypertrophytwenty four |
Reduces neuroinflammation and protects against cognitive impairment in neurodegenerative micetwenty five |
Human studies have also shown that glycine protects against a variety of chronic diseases. Rand points out:
„The benefits of glycine are generally related to improved blood sugar levels, fasting insulin levels, and triglycerides, as well as lower sleep requirements, improved brain function and health, and overall aspects of vitality.“
Other health benefits of glycine
Other health benefits of glycine include:
- improved sleep26
- Glycine inhibits the consumption of nicotinamide adenine dinucleotide phosphate (NADPH), thereby reducing inflammation and oxidative damage. NADPH is used as a reducing electron storage to recharge oxidized antioxidants.
- stress reduction27
- Improved wound healing28
- Improved gut health29
In his article „Gelatin, Stress, and Longevity“ he says:30 The late biologist Ray Peat reviewed a long list of health conditions that could be prevented or alleviated by supplementing with glycine and increasing intake of collagen and gelatin. These include:31
fibrosis |
Most bleeding problems such as nosebleeds, excessive menstrual bleeding, bleeding ulcers, hemorrhoids, and stroke. Pete says that taking glycine immediately after a stroke can help limit the damage and speed recovery. |
Epilepsy, by increasing the amount of stimulation needed to stabilize the nerves and activate them |
Multiple sclerosis (MS), due to its anticonvulsant effects |
Conditions involving excess prolactin, serotonin and/or cortisol, such as autism, postpartum and premenstrual problems, Cushing's disease, diabetes, and impotence. |
Malaise |
muscular dystrophy and myasthenia gravis |
metabolic disorders32 |
Non-alcoholic fatty liver disease (NAFLD)33 |
schizophrenia34 |
How to optimize your glycine intake
There are several basic options for optimizing your glycine intake.
1. Glycine makes up about a third of collagen and gelatin, so eat more collagen- and gelatin-rich foods. Examples include homemade bone broth made from the bones and connective tissue of grass-fed, organically raised animals and chicken broth made from organic chicken feet. Nails in particular are rich in collagen.35
Animal foods such as seafood, red meat, poultry, and dairy products also contain taurine, which increases glycine, which indirectly increases glycine levels as well.36
2. Take high-quality collagen and gelatin supplements.
3. Take glycine supplements. Pure glycine is available in powder form and has a mild sweet taste, so it tends to be very affordable and easy to consume.
Considering its many health benefits, getting enough glycine in your diet can go a long way in improving your health and longevity. Currently, no daily requirements or upper limits for glycine have been established, making it difficult to make specific recommendations.
That said, doses of 3 to 5 grams have been shown to improve sleep.37 a study38 It is estimated that most people lack about 10 grams of what their bodies need for all metabolic uses each day.39 Additionally, in a study of people with metabolic syndrome, consuming 15 grams of glycine a day for three months reduced oxidative stress and improved systolic blood pressure.40 This should give you a rough idea.