Researchers of a new study found that increased levels of an amino acid in the body may be a major contributing factor to the development of diabetes.
The level of Tyrosine, one of the 22 amino acids in the body, tends to be higher in people who are obese or diabetic. Alternately, people who are obese and have a higher level of Tyrosine are also at a higher risk of developing diabetes, researchers from Barshop Institute for Longevity and Aging Studies at the UT Health Science Center found, according to a press statement.
"It was unknown whether this was simply a marker of diabetes risk or could be playing a direct role in the disease," study senior author Alfred Fisher said in the release. "Our work suggests that tyrosine has a direct effect."
Fisher has conducted previous studies that looked into tyrosine's effect on insulin signaling in an animal model called C. elegans (roundworms). He then extended his research to humans. The new study was on a small group of humans. The researchers augmented tyrosine levels in study participants for a short period and observed whether these changes the ability of the body to respond to insulin, which is a key hormone involved in controlling blood sugar levels. This wasn't detrimental to participants, as the increase was transient and well below the level of what is clinically relevant.
In the previous study, Fisher found that increasing the levels of tyrosine in roundworms promoted their longevity. Worms with mutations of certain genes lived 10 to 20 percent longer. One of these genetic mutations led to an almost 60 percent increase in life span, according to the press release.
"In both humans and worms, the effect is due to an inhibition of insulin signaling," Dr. Fisher said. "Interfering with this pathway produces longevity in worms, whereas in people it leads to insulin resistance and an elevated risk of developing diabetes."
Though the effects of tyrosine on the human body have been the subject of many studies conducted in the past, this is one of the few researches that linked this amino acid to diabetes.
"The key concept that comes out of our latest paper is, rather than amino acids being only building blocks in our bodies, they are detected and produce changes in physiology, including potentially undesirable ones such as diabetes in humans," Dr. Fisher said.
