Glycine and Longevity

Summary

Glycine Impacts Aging Via

• Loss of proteostasis
• Mitochondrial dysfunction
• Epigenetic alterations
• Altered intercellular communication
• Deregulated Nutrient Sensing
• Crosslinking

The role of glycine in aging and longevity

Glycine is the smallest amino acid present in our body. It is considered a “conditionally essential” amino acid, meaning that under certain conditions creation by your own body is limited. Glycine is highly concentrated in collagen, which is a protein that builds up our skin. 

Glycine and lifespan extension

Various studies discovered that glycine can extend lifespan. 

In one study, glycine extended lifespan in mice, especially in males (R). In this study the extension of lifespan was only 2 percent in female mice, and 6 percent in male mice. A study in rats found a lifespan extension by 30-40 percent (R). In various other organisms such as in fruit flies and the little worm C elegans, glycine extends lifespan (R,R). 

Scientists claimed they could “reverse aging” in human cell lines by adding glycine to them (R,R). Adding glycine to fibroblasts from 97-year-old people restored their mitochondrial function to much younger levels (R). This research was done in petri dishes. How glycine behaves in the human body is more complex. However, a large body of research has shown many beneficial effects on health and aging in humans. 

Glycine’s role in epigenetics

Glycine has epigenetic effects, especially on the mitochondria, the power plants of our cells (R).

The epigenome determines which genes are switched on or off.

The mitochondria are small compartments in our cell that produce energy, but that also have their own DNA (genes). Glycine can impact the gene expression of these mitochondrial genes.

This could be one of the reasons why glycine can extend lifespan. 

One of the ways in which glycine can extend lifespan is by acting on the methionine system (R). This system ensures proper methylation of all kinds of substances in our cells, including our DNA.

Methylation means putting methyl groups (small molecular groups) on specific substances. Many molecules, such as our DNA, various neurotransmitters, or proteins need these methyl groups to function properly. 

Glycine is in fact the only acceptor for methyl groups, and can in that way clear an excess of methionine. Too much methionine is not healthy: methionine is converted into homocysteine, a substance that has been associated with accelerated aging and aging-related disorders (R). Glycine can reduce methionine levels in the blood. 

Other roles of glycine in health span and lifespan

Glycine is also a substance that activates glycine receptors that inhibit specific cells, like specific nervous cells and macrophages which are involved in various inflammatory processes. 

Glycine can also decrease oxidative stress (R) and improve a decline in aging-related insulin sensitivity. Glycine can also lessen inflammaging (aging-related low-grade inflammation)(R,R). 

Glycine is a chaperone. Chaperones are small molecules that gently “stick” to proteins, surrounding and protecting the proteins from damage, and preventing them from accumulating. Protein accumulation plays an important role in the aging process. 

Glycine can reduce glycation and the formation of advanced glycation end products (AGEs) (R,R).

Glycation is the process in which sugar molecules stick to proteins and link (glue) them together, or damage them. The continuous glycation of our tissues is one of the reasons why we age.

Glycation of proteins in the skin (creating sugar crosslinks between skin proteins such as collagen), makes the skin more stiff, contributing to skin wrinkling and aging. Glycation of the collagen and elastic proteins in the blood vessel wall contributes to stiffer blood vessels. 

Glycine and sleep, skin health and glutathione

Besides all these (and more) beneficial effects on the aging process, glycine can also have some direct effects on our bodies. 

For example, glycine can boost sleep quality. More specifically, glycine can improve how people feel after sleep. It can improve “fatigue”, “liveliness and peppiness” and “clear-headedness” (R,R). Glycine can calm the mind and contribute to more restful sleep (R). 

Glycine is the main amino acid in collagen, an important component of the skin. That is why glycine is sometimes added to skin creams. Oral intake of glycine can improve skin health and reduce the formation of wrinkles by increasing collagen production. 

Glycine is a building block for glutathione, an important antioxidant and repair molecule that our cells produce. Supplementing with glycine can improve glutathione production, leading to reduced oxidative stress in elderly people (R).

Some athletes use glycine to improve muscle function, joint health, and recovery time (R).

Should you consume more collagen to get more glycine?

To increase your uptake of glycine, the consumption of bone broth or chicken skin or pork skin is often advised because these foods contain lots of glycine.

However, these foods contain many other amino acids and proteins, and are of animal origin.