Glycine is an amino acid found in the largest amount in collagen proteins. Other protein sources contain only a small amount of it. Today we consume much less collagen proteins than our ancestors did, as food made of pig trotters, bone stock, aspic, tripe and such are not very popular. Therefore, the amino acid ratio in our protein intake has significantly altered. (For example, glycine is reduced compared to other amino acids.) This was not typical during our evolution, thus we might suspect that this has negative consequences. The beneficial effects of glycine supplementation also confirm this suspicion.
Optimal blood sugar levels
It reduces the blood sugar elevating effects of
glucose (and thus carbohydrates) remarkably. It improves the efficacy of insulin, though hardly increases the amount of it, and it also raises the level of the beneficial glucagon, the “counterpart” of insulin. It decreases high blood lipid levels observable in insulin resistance.
Our skin contains large amounts of collagen, thus
glycine. Collagen peptides reduce wrinkles, increase skin elasticity, hydrate and rejuvenate – well-known and researched effects. The effects of collagen result mostly from its high glycine content. Collagen, glycine, vitamin C, grape skin and seed extracts and bioflavonoids can be a great combination when caring for the youth of our skin from within. Nervous system A small amount increases wakefulness and blood circulation in brain microcapillary vessels. Moreover, according to various research studies, it can be effective in the treatment of depression, schizophrenia and OCD (obsessive-compulsive disorder).
There are only animal studies on this issue, but based on these research studies it improves hepatic and renal function and promotes the production of glutathione, a strong detoxifying and antioxidant agent.
A number of research studies focused on the effect of glycine on sleep in humans. These concluded that consuming glycine before going to bed (3 grams in sucking pills) improves the quality of sleep, helps fall asleep faster, reduces the effects or early waking and makes us more rested even with less sleep. (Six hours of sleep with glycine resulted in a much better sleep than eight hours without it.)
Glycine is a great sweetener too!
It does not have any aftertaste, it is heat resistant and its sweetening
properties are similar to those of sugar. Unlike polyalcohols (e.g. xylitol, maltitol, erythrite), it does not cause digestion problems. It does not deceive our body, since there are no empty calories behind its sweet taste, as it is the case with most sweeteners, for glycine is a protein and our body treats it as such. (Sweet taste means a source of sugar and our body can actually produce sugar from glycine if necessary, thus it does not cause hypoglycemia.) Due to its restraining effect on blood sugar elevation, it is a great substance to sweeten cakes and other snacks – with high carbohydrate content – as it keeps their sudden blood sugar increasing effects at bay.
Decreased caloric intake in mice – with normal
supply of useful nutrients – increases their life span. Such effects were demonstrated in monkeys and partially in humans as well. (Life-long studies about calorie restriction in humans are obviously not possible due to ethical reasons, therefore the conclusions were drawn based on measurements of telomere length, for example.) An even longer life span (+40%) could be achieved in mice compared to calorie restriction by restricting the intake of an amino acid called methionine. Similar results were achieved later when the diet of mice was supplemented with glycine. This is because glycine limits the utilization of methionine from food and thus it balances the ratio of amino acids absorbed into the blood. This has not been studied in humans yet, but it is supposed to be similarly useful. As most foods contain lots of methionine, a low-methionine diet would be difficult to maintain in practice. However, consuming glycine after eating (e.g. desserts or drinks sweetened with glycine) imitated the effect of a diet with decreased methionine intake for longevity, as glycine limits the absorption of methionine.