The Amino Acid Taurine Reviewed: What Benefits Does Taurine Supplementation Offer?
Taurine is 2-aminoethanesulfonic acid: a sulfur-containing amino acid. It was originally isolated from ox bile, hence the name (the scientific name for the ox is Bos taurus).
Unlike most other amino acids, taurine isn’t incorporated into proteins, but exists in free form in the intracellular space of different tissues.
Taurine appears to be particularly abundant in skeletal muscle. Although human data is limited, animal experiments have shown taurine depletion is associated with impaired exercise capacity and age-related loss of muscle function.
Taurine plays a number of important physiological roles, including:
- facilitating the digestion/absorption of fats (via formation of bile salts)
- maintaining cell volume (osmoregulation)
- antioxidant functions
- anti-inflammatory/immune functions
- anti-arrythmic/cardiac functions
- neurological/retinal development
It should be pretty obvious by now that taurine is a critical nutrient! Nonetheless, taurine is not an essential amino acid, as it can be synthesized in the body from the amino acids methionine or cysteine. It is, however, considered to be “conditionally essential”—that is, there are times when the body cannot make enough to meet demand, so additional taurine needs to be supplied. Fortunately, taurine is also available from dietary sources: primarily meat and fish. So is there any use for taurine supplements?
The answer is a qualified “maybe.” Studies have revealed potential therapeutic uses for supplemental taurine, such as prevention of diabetic neuropathy, reduction of blood sugar levels (hyperglycemia), treatment of diabetic retinopathy, mood stabilization, cardioprotection, and treatment of duchenne muscular dystrophy. Additional research is needed, however, to clarify taurine’s role in treating these conditions.
What about healthy people…or bodybuilders? It’s an interesting question. Taurine is often added to certain products marketed to the bodybuilding community, such as pre-workout stimulants/energy drinks and creatine transporters – so let’s take a closer look at the claims made for the addition of taurine to these products.
Pre-workout stimulants/energy drinks
Probably the best-known use of taurine is in “Red Bull” energy drinks, where it’s combined with caffeine and glucuronolactone. Red Bull itself has been studied, and reports confirm that it’s effective for enhancing mental and physical performance, but there is little information on what—if any—role taurine plays in producing these effects. High dose experiments with rats and mice have shown that taurine can influence mood/behavior by acting as an “anxiolytic”—meaning that it reduces anxiety.
Clinical trials in humans for controlling manic symptoms in subjects with bipolar disorder are currently being conducted, but there is little data available yet. At this point, it’s not known if taurine has nootropic activity in humans at the doses commonly seen in energy drinks or other stimulant supplements (1–3 g). Thus, it’s an open question whether the observed effects of Red Bull are due to synergy between taurine and caffeine, or—as some researchers think—due to the caffeine alone.
Taurine is also included in a number of pre-workout supplements such as SAN Fierce, BSN NO-Xplode, and Met-RX Xtreme Amped Up Energy. As in Red Bull, however, it’s combined with caffeine and other active compounds, so it’s impossible to determine the actual contribution that taurine makes to these formulas.
Taurine is often included in these products to:
- improve insulin sensitivity.
- act as a “cell volumizer.”
- reduce oxidative stress.
How it may produce these effects requires some explanation, so bear with me…
To begin, it’s been established that creatine uptake is enhanced by consuming simple carbohydrates with it.
Compounds that improve insulin sensitivity and glucose disposal (such as alpha-lipoic acid), provide an additional boost.
This is the rationale for many creatine transport formulas on the market, which provide various forms of creatine in combination with high-glycemic index carbohydrates (e.g., glucose, maltodextrin) and insulin sensitizers.
Research suggests that taurine has hypoglycemic effects and can improve insulin sensitivity. This is based—once again—primarily on studies in rats/mice. These experiments have shown that supplemental taurine can modify insulin signalling and improve blood glucose, lipid levels and oxidative stress.
The limited data in humans, however, is conflicting: in one study, supplementation with 1.5 g taurine/day for 8 weeks had no effect on insulin secretion/sensitivity in overweight men with a predisposition to Type II diabetes. Conversely, a more recent study using twice as much taurine (3.0 g/day) demonstrated it reduced experimentally-induced insulin resistance in overweight/obese, non-diabetic men.
Does this mean taurine can improve creatine uptake in the same way that alpha-lipoic acid can? Perhaps…although there’s no direct proof and—as one researcher put it, “…it’s much too early to recommend taurine as a dietary supplement” for its putative effects on blood glucose and insulin.
But if there are any lessons to be learned from comparing these two studies, it’s that the dose likely matters. Thus, the taurine in various products may—or may not—be useful, depending on how much is supplied. As Paul has previously pointed out, this is the downside of the proprietary blends frequently used in supplement formulas.
“…I dislike “proprietary blends” since they disguise the true amount of each ingredient, making it very difficult to assess for efficacy.
In other words, you can never really tell if an ingredient is merely “label dressing” (i.e., it looks great on the label, but there’s so little of it in the formulation it’s impossible for it to elicit any sort of effect) or whether it is present in a strong enough dosage to be useful. The latter, in my opinion, becomes less and less likely the more intensive a formula becomes.”
Some formulas provide very little taurine—just enough to claim it on the label. Needless to state, it’s doubtful that a few milligrams will be of very much use.
What about taurine as a cell volumizer? It’s true that taurine plays an important role as an “osmoregulator”—that is, as a regulator of the fluid levels inside cells. Nonetheless, there is little evidence to suggest that supplemental taurine can enhance the effects of creatine in healthy individuals. As creatine researcher Richard Kreider noted,
“Although we have found that creatine supplementation…is effective in promoting gains in strength and muscle mass, we have not found that the addition of taurine (3 grams/day for 2 weeks) had any added benefit.”
Taurine’s ability to act as an antioxidant may be the best reason for including it in bodybuilding supplements. Beyond the ubiquitous animal and cell culture experiments, some actual human data exists that shows it can reduce post-exercise oxidative stress and DNA damage. It’s not the only compound that offers this benefit, however.
So, whither taurine? I think the take home message is that it’s a compound with (yet unrealized) therapeutic potential, but the evidence to justify its use as a supplement for healthy people is still limited—more research definitely needs to be done.
On the flip side, it’s non-toxic, so there’s no apparent harm from consuming taurine—in either pure form or as part of a blend. Thus, there’s nothing to lose and possibly something to gain from supplemental taurine, particularly if one is consuming a vegetarian diet low in natural sources of this nutrient.