Taurine is a semi-essential amino acid also called 2-aminoethanesulfonic acid. It has a bad reputation as an energy drink additive, but it is vital for the normal functioning of the human body. Read on to learn how it is made and metabolized, the best dietary sources, and interesting interactions with genetics and health conditions here.
What is Taurine?
Taurine (L-Taurine or 2-aminoethanesulfonic acid) is a sulfur-containing amino acid [1, 2].
Taurine is present in almost any tissue in the body and concentrated in key areas such as the heart, brain, and retina of the eye. A taurine-rich diet can protect the body and promote longevity. Yet taurine has a bad reputation because it’s a popular ingredient in unhealthy energy drinks.
Taurine plays various important roles in the body including regulation of water status in our cells, preventing oxidation in the body, and supporting calcium signaling in key organs. Through calcium regulation properties, it helps to improve the function of cardiac, nervous and musculoskeletal tissue.
Humans are able to produce taurine, but not in sufficient quantities under all conditions. Therefore, taurine is a conditionally essential amino acid for humans, and nutritionists recommend getting some from diet. Some people who can easily become taurine deficient include premature and newborn infants and chronic liver, heart, and kidney disease patients [3, 4].
Taurine is an osmolyte. This means it controls water entry and exit in cells and stops them from changing the cell too much in size. It interacts with fats in cell membranes and stabilizes them, preventing structural changes to the cell [5, 6].
Despite the impressive range of positive effects taurine has on the body, its exact mechanisms of action still remain largely unknown [7].
How the Body Makes Taurine
Taurine is synthesized within the body from the only two other sulfur-containing amino acids: methionine and cysteine [2].
Taurine synthesis mostly takes place in the liver, with the help of the enzyme cysteine sulfinic acid and vitamin B6 (pyridoxine) [8, 9, 10, 11].
Other cells in our bodies are able to take up taurine from the blood thanks to the special taurine transporter (TauT) molecule that is found on cell membranes [12].
Taurine is an essential nutrient for newborn children as they are yet not able to synthesize or retain taurine within their bodies. Breast milk contains the full taurine requirement for infants, as does modern day baby formula [11, 13].
How the Body Removes Taurine
Taurine exits the body as part of bile or urine [11].
The kidneys are able to increase or decrease taurine excretion depending on dietary availability of taurine. High amounts of taurine in urine indicate high dietary intake [14, 15].
When taurine is needed, taurine transporter molecules in the kidneys resorb and conserve taurine in the body [16].
Individuals with compromised kidney function or faulty taurine transporters may not be able to retain sufficient amounts of taurine [17].
Dietary Sources
What Foods are High in Taurine?
Humans’ main source of taurine is dietary, and taurine is naturally present in [11]:
- Shellfish (oysters, mussels, and clams) [18]
- Other meat and dairy products [18]
- Sea vegetables (such as seaweed) [19]
The average daily taurine consumption in Americans are provided as follows:
Human breast milk also contains taurine. The amounts of taurine in breast milk vary depending on the diet of the mother. Omnivorous mothers have been found to contain one and a half times the amount of taurine in their milk as vegetarian mothers [11].
Conditions that Decrease Taurine Levels
What Decreases the Body’s Ability to Absorb or Synthesize Taurine?
Taurine levels within the body have been known to decrease due to surgical injury, chemotherapy, heroin addiction, Tylenol overdose, and many other numerous disease-causing conditions such as trauma, cancer, hypertension, diabetes, epilepsy, and liver disease [11, 20, 21, 22, 23].
Human studies have shown that vitamin B6 deficiency can lead to taurine deficiency because vitamin B-6 is needed for the synthesis of taurine by the body [11].
The essential amino acids methionine is also needed for taurine synthesis by the body. Therefore, reduced methionine intake can also lower taurine levels in the body [24].
A strict vegan and vegetarian diets result in taurine deficiency because they provide little to no dietary taurine [11].
The aging process reduces the body’s ability synthesize taurine [25].
The amino acid beta-alanine may block the action of the taurine transporter in the body and lead to low levels of taurine [26].
The antiepileptic drug vigabatrin also depletes taurine from the retina [27].
Those who are susceptible to taurine deficiency may be advised to supplement. Talk to your doctor if you believe that you may benefit.
Gene Interactions
In rats, taurine supplementation changed protein and gene expression (production). However, scientists are unsure of the relationship between taurine and those genes.
Genes That Increase Taurine
Taurine increased the expression of [28]:
- EAPP
- CMTM2a
- PLAC8
- CCL6
Genes That Decrease Taurine
Taurine decreased the expression of [28]:
- PLAC9
- CRABP1
- CD80
- SPP1
Supplementing With Taurine
Who Uses Taurine Supplements?
- Strict vegetarians and vegans
- Athletes looking to improve exercise performance
- Individuals suffering from the disease conditions mentioned above
- Healthy individuals interested in taking supplements that promote longevity
Manufacturers can make taurine synthetically, and there is no need for animal extractions. Therefore, cheap vegan-friendly taurine supplements are widely available for purchase [29].
Dosage
Note that there is no “safe and effective” dose of taurine for any particular medical condition because no studies have been performed to find one. However, taurine is abundant in most people’s diets.
Up to 3 g of supplemental taurine per day has been found to be safe for adult consumption. There is strong evidence that there are no side effects at doses up to and under this value. Scientists do not recommend a dose greater than 3 g per day [30].
Relatively high amounts of taurine are considered safe for consumption because any excess can be harmlessly passed through urine [30].
Side Effects, Interactions, and Precautions
Side Effects
Side effects noted in uncontrolled trials include temporary itching in psoriasis patients and hypothermia in patients who are unable to produce sufficient amounts of steroid hormones [31, 30].
Taurine may act as a diuretic [32].
Most of the studies have focused on the short-term use of taurine supplements. Therefore, no conclusions can be made regarding the use of taurine supplements for periods greater than 1 year [30].
Interactions
According to a handful of studies, taurine may change the way caffeine affects one’s perception of being tired, though this effect has not been confirmed in humans [33, 34].
A combined high dose of taurine and alcohol is lethal in mice [35].
Carnitine
Taurine and L-carnitine may work together to benefit heart health. In rat muscle cells, L-carnitine and taurine stopped the multiplication (proliferation) and hardening of muscle cells. This may prevent the hardening of blood vessels and stop plaque from accumulating, thus preventing heart disease or atherosclerosis [36].
Note that this synergism has only been demonstrated in rats. The human body may not respond the same way.
Precautions
Pregnant women should avoid using taurine supplements unless directed by a physician; maternal taurine supplementation during pregnancy causes insulin resistance and obesity in rat offspring [37].
Additionally, taurine and taurine-containing energy drinks should not be mixed with alcohol [35].
It is important to use high-quality taurine supplements to avoid potential contamination with harmful compounds.
What About Taurine-Enriched Energy Drinks?
The presence of taurine in energy drinks may decrease the uncomfortable side effects of caffeine, such as heart palpitation, jitteriness, and anxiety. Taurine is usually only added to these drinks to mask the harmful effects of the product [38, 39, 34].
The high caffeine and sugar content of energy drinks containing taurine also nullify any potential health benefits [40].
We recommend strongly against consuming these energy drinks.
Takeaway
Taurine is a sulfur-containing amino acid which is required for the normal function of the human body. It can be absorbed from food or made in the liver from other sulfur-containing amino acids, a process for which vitamin B6 is essential. Eventually, taurine is excreted in the bile or urine.
Meat, shellfish, and sea vegetables (like seaweed) are the best sources of dietary taurine. People who eat a vegan diet are unlikely to get enough in their diet and may want to talk to their doctor or nutritionist about supplementation. Taurine may act as a diuretic and interact with caffeine and alcohol.
