What’s Taurine and Why Do We Care? (Part 1)

**Michael Greger** (0:00)
I'm often asked my opinion about the cause or treatment of some medical condition, but the question to instead ask is what does the science say? What does the best available balance of evidence published in the peer-reviewed medical literature have to say right now? Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. Today we bring you the first installment in our series on taurine. No taurine isn't an astrological sign. And it's an non-essential amino acid that our body can make. But does it make enough for optimal health? What are the pros and cons of supplementing? Let's start with a little background. Energy drinks are widely consumed in the United States with sales exceeding 350 million gallons. There's only like 335 million people in the US., so we each average more than a gallon a year? Is it just the caffeine that people are after? A major ingredient in popular energy drinks is taurine. What is that? Taurine is one of the most abundant free amino acids in our body, free as in not incorporated into proteins. We make it in our own bodies, that's why it's considered non-essential, as in we don't have to get any in our diet. However, premature infants are vulnerable to taurine deficiency because they initially lack some of the enzymes needed to synthesize taurine, but breast milk provides all the taurine they need, and it's often added to infant formula as well. We aren't the only animals who make it. The name taurine derives from the Latin taurus, meaning bull or ox, because taurine was first isolated from the bile of an ox in 1827, decades before it was discovered in people. It's funny, in my search of the medical literature, I kept coming across articles on taurine surgery. What does that mean? That's what they call surgery for bullfighting injuries. Anyway, taurine was first isolated in the 1800s, but not much was known about this molecule until the 1990s, after we found low levels in preterm formula-fed infants. Even though taurine isn't incorporated into proteins, it plays important roles throughout our body. Clues to its importance include the fact that our body has not one, not two, but at least five pathways to make it, and we make a lot of it. If you look down at the bathroom scale and it says 200 pounds, about one-fifth of a pound of that is straight taurine. Other clues can be found in where it's made. The main pathway enzyme is found not only in our liver, but in sensitive tissues like the eye, brain, kidney, breast milk-producing glands, and our reproductive organs. The levels in sperm suggest a protective effect. Taurine is described as a major antioxidant, but it's really only good at squelching one type of free radical, but that free radical produces pro-aging toxins like advanced glycation and products, so that squelching activity is an important function. In addition to our brain, taurine is also found concentrated in our muscles, where it's involved in energy production. Presumably, that's why it's put into energy drinks. Does taurine help with cognitive or physical performance? Probably neither. Like in this study, no benefit for either physical or cognitive ability, with some studies suggesting taurine actually undercuts some of caffeine's beneficial effects on cognition or vigor, or that it helps with one kind of cognitive task, but hurts performance of another. Taurine may be more red herring than red bull, as the human studies often cited to support it have been improperly designed, lack appropriate controls. Put all the studies together, it is little evidence that taurine increases endurance exercise, and it's unclear whether there are any sports benefits like reducing muscle soreness or speeding recovery. Taurine injection might even be detrimental to maximal muscle power in non-caffeine consumers. The picture is just really unclear, which is why I've never really paid much attention to it until boom! This study came out suggesting taurine deficiency was a driver of aging. It was published after I had already submitted the manuscript for my longevity book, How Not to Age, so I've been eager to dive into the topic to see if there was anything there. As we age, the taurine levels in our body fall by as much as 80%. This may be due to the depletion of the taurine-synthesizing enzyme in our liver, suggesting we may need to start getting more taurine in our diet as we age. The reason it was concluded that taurine was a driver of aging is because when attempts were made to restore youthful levels in animals to taurine supplementation, this reversal of taurine deficiency increased the health of worms, rodents, and primates, and increased the lifespan of worms and rodents. We'll dig into this important study next.