Prior to the buoyant accounts of the study with the alluring title “Taurine deficiency as a driver of aging,” it was mostly people who read the list of ingredients on the label of the “energy drink,” Red Bull, who were familiar with the chemical. Why does the beverage contain taurine? That is somewhat of a mystery. The only information provided on Red Bull’s website is that “taurine is an amino acid, naturally occurring in the human body and present in the daily diet.” No argument with that. Well, maybe a little one. Taurine is not exactly an amino acid, it is an aminosulfonic acid and unlike common amino acids, it is not incorporated into proteins. It is found in fish and meat, and while it has many important biochemical functions in the body, it is not an essential component of the diet because the body can make it from cysteine, an amino acid that is readily available from proteins in the diet.
It was back in 1827 that German chemists Friedrich Tiedmann and Leopold Gmelin first isolated a compound from bull bile that came to be called “taurine” from the ancient Greek word for bull or ox. A bull certainly conjures up an image of energy, which may be the reason that taurine was incorporated into the beverage. That in a curious way justifies the logo of two bulls charging at each other on every can of Red Bull despite the fact that there is no evidence of taurine being a stimulant. The stimulant in Red Bull is caffeine, albeit there is less present than in a cup of coffee.
Now on to the study. Taurine is present in human blood and a number of conditions ranging from diabetes and obesity to hypertension and inflammation are associated with lower levels. Furthermore, blood levels tend to decrease with age. These observations do not prove that taurine has a causative role in disease or aging, but that possibility is worth exploring. That is exactly what the authors of the paper in Science did. Worms, mice and rhesus monkeys fed taurine were compared in various ways with worms, mice and monkeys who did not receive the compound. The life span of the worms and mice increased, significantly in the case of the mice. Females and males lived 10% and 12% longer respectively. Since monkeys live much longer than mice, we will have to wait for follow-up studies to see if the monkeys also live longer.
The goal of anti-aging therapies is not only to increase the life span, but also to increase “health span.” Extending life is not particularly desirable if the added years are filled with misery. That is why it is noteworthy that both in mice and monkeys, health span was increased as determined by decreased DNA damage, reduced markers of inflammation, less fraying of chromosomes and improved functioning of mitochondria, the organelles in cells where energy is generated. Taurine also suppressed older, damaged “senescent” cells that refuse to die and begin to excrete inflammatory cytokines that may trigger aging and diseases such as Alzheimer’s. All that sounds great. But time to look at some numbers.
In the trials where the greatest benefits were seen, the animals were given a gram of taurine per kg of body weight every day. That is far, far more than the roughly 40-400 milligrams in our daily diet. No point reaching for a Red Bull. An average adult would have to consume about 63 cans a day to equal the dose of taurine given to the test animals. Neither can supplements that commonly have 500-1000 mg per capsule mimic the amounts given to the animals. The researchers who carried out the studies state clearly that in the absence of human clinical trial, supplements are not recommended. While taurine in small doses seems safe, no humans have ever been exposed to doses of taurine equivalent to what was used in the animal studies.
Incidentally, the taurine in Red Bull is not isolated from bull semen as some circulating misinformation claims. Although the compound is found in bull semen, for commercial purposes it is synthesized in the lab and is therefore suitable for anyone wishing to avoid animal products. Another bit of misinformation is that Red Bull was the target of a class action lawsuit that claimed the beverage was falsely advertised because it did not actually “give you wings” as the slogan says. There was indeed a class action lawsuit but it was about a lack of any evidence that the beverage had a stimulating effect beyond what a cup of coffee could deliver. Red Bull settled for $13 million, claiming that it stood by the correctness of its ads but did not want to engage in the expensive process of litigation.
The company hasn’t given up on ads that portray Red Bull as being more than just a tasty beverage. A recent ad features a dog with a walking stick that after downing a Red Bull jumps on a skateboard, performs a double-loop, and then flips and catches the board like a pro as a voice-over asks “who says you can’t teach an old dog new tricks?” Cute. I wonder if the ad writers will learn a new trick from the taurine study and go on to hype Red Bull as a remedy against aging.
The fact is that aging is a complex, multifactorial process that involves numerous alterations of the myriad biochemical reactions that constitute life. Suggestions that changes in the amount of one of the thousands of biochemicals found in the bloodstream is the driver of aging, as the title of the paper in Science claims about taurine, is….well, a lot of bull.