What are the relationships between Glycine, Methionine and Homocysteine?

Amino acid metabolism is a very complex subject. Naturally, it is directly linked to your diet and its protein content in particular. Protein foods, of course, help renew your organic tissues and muscles, but the balance between amino acids is also very important for your health. We have often spoken to you about the essential role of glycine . On the other hand, the issue of homocysteine ​​is generally not discussed much. We will discuss it in detail in this article…

As you know, the consumption of red or white meat is the majority in our modern diet. Meat provides you with all the essential amino acids that you need, and among them, methionine. Little known to the general public and athletes, methionine is nevertheless essential for the formation of proteins, among other roles. However, an imbalance between methionine and glycine intake will not necessarily be favorable to health. This is called the homocysteine ​​problem. You also know that glycine is too rare in our diet, unless we often consume the gelatinous parts of meat, but this is not very common. But then, how could an excess of methionine be harmful to health?

Methionine is metabolized in the liver to homocysteine

Methionine is essential for protein synthesis, but an excess will also result in excessively high homocysteine ​​levels. Indeed, when methionine passes through the liver, it is converted into homocysteine. Thus, a high meat consumption could lead the body to synthesize an excessive amount of this amino derivative, homocysteine. A problem then arises because this amino acid is also indirectly linked to health problems, particularly cardiovascular and chronic diseases. Conversely, certain micronutrients, such as folic acid (a B vitamin), allow the conversion of homocysteine ​​into methionine. Thus, folates contribute to the balance between these two amino acids. Since folic acid metabolism is dependent on vitamin B12, we can only advise you to carefully monitor your B vitamin intake. , especially folic acid and B12, preferably in the form of methylcobalamin. Naturally, a good multivitamin will provide you with all the B vitamins.

Rebalance the ratio between methionine and homocysteine ​​with glycine

As we just mentioned, folic acid is a vitamin that intervenes in the methylation process, allowing a reconversion of homocysteine ​​into methionine and dimethylglycine (2 methyl groups + glycine), neutralizing excess homocysteine. Let's say that vitamin B6, B12 and B9 are involved in this metabolic process. At the same time, the amino acids serine and glycine are necessary for this physiological process. Serine as a dietary supplement is quite rare but glycine is abundantly synthesized and inexpensive.

It is also an amino acid used by the food industry as an acidity regulator because glycine has a slightly sweet taste. However, we would not advise you to gorge yourself on junk food and junk food because they are sweetened with glycine, that's obvious. Gelatin is also a more or less valid solution because it is a derivative of collagen. But here too, it is a bit of a false solution because gelatin is a form of protein degraded from collagen . This will therefore not really constitute a healthy intake of glycine or amino acids of good nutritional quality. Jellied desserts and other confectionery may provide you with a little glycine but this is also a particularly unhealthy dietary solution.

Glycine deficiencies are a concern for the majority of sedentary and athletic people.

Furthermore, nutritional requirements for glycine are higher than you might be told. In fact, glycine deficiencies are just as common as those of vitamin D or magnesium. Scientific research has proven that dietary intake of glycine is largely deficient for a large majority of individuals. This is easily explained since glycine is not only essential for the synthesis of collagen but it also acts as a glucoforming amino acid. It is also used for the endogenous synthesis of creatine , it is involved in the production of bile salts or more indirectly, hemoglobin and certain antioxidant molecules. From there, the unmet nutritional needs for glycine would be 6 to 12 grams per day in humans on average.

Glycine is not only essential for collagen but also for creatine and other metabolic processes

Considered a non-essential amino acid, the body generates a small part of it from serine, but this endogenous synthesis proves largely insufficient to cover all of the body's needs. This deficiency, which is harmful to health, will often result in joint problems, arthritis and osteoarthritis with age. To this end, the quality of your diet must therefore be considered both in the short and long term; the latter could perhaps be linked to the lack of glycine , which leads to increasingly difficult collagen renewal over the years. Research has also shown that this chronic deficiency was due to distant genetic reasons by studying several mammals that presented joint problems linked to aging. Comparisons with humans tend to validate this hypothesis.

Ultimately, exogenous glycine supplementation would be the simplest way to reduce blood homocysteine ​​levels.

To summarize the situation, let's say that excess homocysteine, generated by excessive methionine intake, are risk factors—indirect—for cardiovascular health and other chronic diseases. Conversely, glycine intake would be the best way to prevent homocysteine ​​from rising to problematic levels. However, stuffing yourself with gelatin and sugars or fatty, unappetizing meats is not a solution either. It would have no positive effect, in fact...

More reasonably, an exogenous intake of glycine through supplementation remains the simplest way to maintain homocysteine ​​at reasonable blood levels. Let's add that the solution to the problem lies largely in the methylation process, as we have already specified. To this end, serine, glycine but also trimethylglycine (3 methyl groups + glycine) or betaine will happily participate in the proper functioning of this process. Methyl groups are all the more essential to your body as they participate in the repair of your DNA, one more reason to ensure that these molecules are supplied to your body daily. In addition, taking a glycine dietary supplement will indirectly save your methyl groups, useful for other purposes, and for your DNA in particular. This simple observation, as well as others indirectly linked to it (synthesis of creatine , hemoglobin, antioxidant, anti-inflammatory, etc.), also lead researchers to say that glycine is very well positioned as a molecule with “anti-aging” properties or at least, that it actively participates in human longevity...