Amino acids are one of the main components of proteins which count for 20% of the human body. Not only this, amino acids play an important role in the rehabilitation of our tissues, restoring injuries, the transportation of nutrients and several other functions. In this article, we are going to focus more on the sulfur amino acid which is a subcategory of amino acid family. Cysteine (Cys) and methionine (Met) are examples of sulfur amino acids.
In the study review titled “Disease prevention and delayed aging by dietary sulfur amino acid restriction: translational implications”, conducted by a team of researchers from Penn State College of Medicine and presented in Annals of the New York Academy of Sciences, are given evidence that diets, which include no foods supplying the body with surplus sulfur amino acids, were able to indicate health improvements.
It’s been years since scientists have been conducting studies according to diets which have had reduced number of sulfur amino acids and the results of these reductions on animals. In one study with rat subjects, it has been observed that the overall lifespan of the animal did significantly increase, about 40%, as a result of a diet which restricted the supply of methionine. Not only this but these animals were also losing some weight because of this diet, decrease in oxidative stress, altered metabolism etc. On the other hand, this restriction has also disadvantages because the sulfur amino acids have an important role in the human body. Saying this, from the study review it has been seen that the restriction of Met has also led to discouraging of growth. Indeed, this is the main reason that this dietary orientation has not convinced all scientists and experts about its effectiveness on humans.
Nonetheless, the diet with Met restriction on adult animals has shown the same effects for what is mentioned in the above paragraph. As a matter of fact, this is a very important fact because scientists won’t have to worry about the delay of growth issue when applying this diet to grown-ups. Except for the delay in growth, there weren’t other significant side effects, stated the researchers. The appliance of this specific diet is not yet ready for humans but on the other hand, we humans have conducted studies and discovered that sulfur amino acids play a role in cancer, cardiovascular diseases, increasing the body’s weight and also the metabolic syndrome. As a conclusion, this is a further significant factor which supports the idea of the reduction in Met or Cys supply even though the data about diet in humans is unsatisfactory.