By Amy Norton HealthDay Reporter
A new study suggests that an amino acid found in fish, meat and energy drinks could be a key regulator in the aging of animals.
Experts warn, however, that Red Bull is not a fountain for youth.
Researchers discovered that taurine deficiencies were a major factor in aging lab mice. Taurine levels declined naturally with age. However, giving mice in their middle years a daily supplement of taurine for a year effectively slowed down the aging process.
America's 25 healthiest communities
View All 29 Slides
Comparing lab mice that were fed a placebo, mice who consumed taurine lived 10% to 12% more.
The mice also lived their best lives as lab mice -- they were leaner and had stronger muscles and bones, showed fewer anxiety and depression-like behaviors and maintained a "younger" immune system.
The study leader Vijay Yadav is an assistant professor at Columbia University in New York City, who specializes in genetics and developmental biology.
Scientists observed the same effects when they repeated the experiment on monkeys of middle age.
Researchers and other experts warned that the mice and monkeys studied in controlled lab settings are not real people who live their complex lives in the world.
The research does not prove that taurine can make humans healthier and live longer.
Yadav stated that "we do not recommend people to buy taurine from the shelves."
He and his colleagues believe that taurine supplements need to be tested in a controlled clinical trial.
Henning Wackerhage is a professor from the Technical University of Munich in Germany and co-author of the study.
It could be as simple as having adults of middle age take taurine every day or a placebo, and then monitoring them to see if they have any health differences.
The human body can synthesize taurine, but it can also be obtained from food. Yadav says that shellfish contain the highest amount of taurine, but it is also present in poultry, beef, and dairy products.
Amino acid "building blocks" are usually used to form proteins. Wackerhage explained that taurine is a different molecule: it's not incorporated into protein. Taurine is believed to play a role in immune function and the central nervous system. It also has anti-inflammatory properties.
Yadav explained that it is not clear if the amino acid in people helps to drive the aging or "just rides along with the process."
Researchers tested taurine supplements only on lab animals in the new study published in Science journal, June 8, 2008.
They also looked at human data. In a study of 12,000 European older adults, they found that those with higher levels of taurine were less likely than others to suffer from obesity or type 2 diabetics.
Joseph Baur is a professor of medicine at the University of Pennsylvania Perelman Medical School in Philadelphia.
Baur, the author of a comment published along with the study, suggested that taurine could be affected by certain human diseases.
He added that the chicken-and-egg dilemma is the reason why animal experiments are so important. Baur said that the animal experiments "show for the first-time how taurine is a key driver in increasing longevity".
This is a research step, not a lifestyle recommendation. Baur says that for the average person, a healthy lifestyle should include a healthy diet and exercise, as well as avoiding smoking.
Baur stated that new ideas like taurine supplements should be studied and tested in controlled clinical trials. It's easier to mess things up than make them better. Even with molecules that appear to be safe.
A researcher who wasn't involved in the study says the results are interesting but is worried about the spin that the supplement industry may put on them.
"They can promote this as an antiaging supplement tomorrow," Dr. Pieter Cohen said, an associate Professor at Harvard Medical School that studies the quality and content of commercial dietary products.
Cohen pointed out that supplements in the United States are not subjected to the same regulations as medications. This means that supplements do not need to be tested for effectiveness before they can be marketed. Consumers cannot be certain if the supplement contains what is on its label.
Yadav emphasized that although taurine is found in meat, a diet high in meat has been linked to negative health effects. He said that his team did not study this. They also didn't study energy drinks which contain caffeine and sugar.
Researchers in another part of the study had athletes and couch-potatoes pedal on exercise bikes until they were exhausted. After the exercise, many showed an increase in taurine levels in their blood. Experts said it was not clear whether exercise boosts taurine production or whether taurine is one of the reasons that exercise may be good for you.
Researchers acknowledged that many of the benefits observed in animal experiments "seemed too good to be real."
Wackerhage stated that "my take" is that taurine appears to affect the engine of aging.
Cohen's view was more reserved. He said that with something as complex as human aging it would be surprising to find out that one amino acid could have such a powerful effect.
Researchers said that the study was funded entirely by grants from foundations and government agencies, with no involvement of supplement companies.
SOURCES: Vijay Yadav PhD, assistant Professor, Genetics and Development, Columbia University Vagelos College of Physicians and Surgeons in New York City, Henning Wackerhage PhD, professor of exercise biology at the Technical University of Munich in Munich, Germany, Joseph Baur PhD, professor of physiology at University of Pennsylvania Perelman School of Medicine Philadelphia, Pieter Cohen MD, general internist with Cambridge Health Alliance Somerville Mass., Associate Professor of Medicine Harvard Medical School Boston, Science