While I was reading an article about supplements that may boost athletic performance, in a paragraph about how to increase stamina I saw the word “carnosine”. I couldn’t exactly remember what exactly carnosine is and why is it important for our bodies. So I started to search the Internet and one fact about carnosine caught my eye. One study’s result shown strict vegetarians have 50% or less carnosine in muscle tissue then omnivores. As a vegetarian and someone who is exercise regularly, this was very interesting. Every nutritionist will tell you if you choose to avoid or remove from your diet a particular food group, you should find an appropriate replacement for the nutrients that this food group contains. And although the research on this subject is very scarce and there is not enough evidence, you can find a recommendation from some authors on the Internet: “Carnosine supplementation would probably be a good idea for vegetarians and vegans”. I also have to say I’ve never really used any pre-workout supplements before (I always thought three cups of strong coffee is enough to survive work + training), so I never really paid attention or studied these products. But you live and you learn.
What is carnosine?
Carnosine is actually a dipeptide, which means it is made up of the two amino acids: beta-alanine and histidine. Histidine is an essential amino acid and it is plentifully supplied in all food sources. But beta-alanine, although non-essential amino acid (our bodies create it internally in the liver), is one amino acid not found in plant. The only dietary source of beta-alanine is meat and fish containing carnosine and its methylated derivatives (homocarnosine, anserine and balenine). Beta-alanine can be synthesized within the body during degradation of thymine, cytosine, and uracil (nucleobases in the nucleic acid of RNA and DNA) in the liver. Also, our gut microbes can make beta-alanine from L-aspartate. But it is believed that in muscle these processes are often slow and normal level of carnosine is hard to maintain (without dietary intake).
Carnosine is present at particularly high concentrations in muscle, heart, and brain. The majority of the body’s carnosine is present in the skeletal muscles. Also, in our bodies, fast-twitch muscle fibers (or type II fiber muscles which mainly use anaerobic respiration and are better for short bursts of speed) have markedly higher carnosine content compared to slow-twitch muscle fibers (or type I muscle fibers mainly used in endurance exercises). As type II muscle fibers are primarily used in high-intensity workouts, sprinters have higher muscle carnosine content than those who prefer endurance exercises like running or marathon.
Carnosine levels are also higher in men than women and decline with age in both genders.
Supplementation with beta-alanine may be the most effective way to increase muscle carnosine content. Because beta-alanine plays an important role in carnosine biosynthesis (it is a precursor of carnosine), carnosine levels in plasma are limited by the amount of available beta-alanine. Supplementing with beta-alanine can increase muscles carnosine levels by 80%. In addition, supplementation with beta-alanine can decrease fatigue in athletes and increase total muscular power output. Supplementation with carnosine contrarily is not as effective as supplementing with beta-alanine since carnosine, when taken orally, is digested in our bodies to its two components (histidine and beta-alanine).
Carnosine has been excessively researched for its anti-aging properties. Carnosine is thought to act against several mechanisms associated to aging process due to its presumable biochemical properties, including antioxidant, binding of transition metal ions (prevention of free radicals formation), muscles pH buffering, anti cross-linking, and reactive carbonyl species (RCS) scavenger. It has been recognized as an antioxidant and a free radical scavenger (although antioxidants found in fruits and vegetable have much greater antioxidant potential). Also, carnosine is useful in helping prevent damage caused by too much sugar in the body. Excess sugar in the body can bind to proteins (or lipids), which not only damages the protein, but the glycosylated protein can stimulate inflammatory processes. So-called advanced glycation end products (AGEs) are formed during this process. AGEs can be one factor in aging and can initiate development of some age-related chronic diseases. The protein-carbohydrate binding can also lead to proteins sticking to each other, a process known as cross-linking. A great example of cross-linking is the formation of cataracts in the lenses of the eyes as we age. It is thought cataracts are formed due to cross-linking of proteins.
Animal studies show carnosine may diminish the glycosylation process and thereby prevent cellular damage caused by above-mentioned processes.
But carnosine levels in our bodies decline as we age, leaving us more susceptible to metabolic disorders like diabetes, atherosclerosis or even worse Alzheimer’s disease.
Improved athletic performance
In sports nutrition, carnosine is known for its ability to buffer pH in a working muscle. During high-intensity exercise the levels of hydrogen ions (H+) rise. This rise in H+ dramatically lowers the pH within muscle cells, which leads to fatigue. By regulation of muscular pH values, beta-alanine (which will be transformed to carnosine) helps athletes to perform better and exercise for longer period of time. That is why in most pre-workout mixtures, one of the ingredients is almost always beta-alanine. The benefits associated with beta-alanine supplementation during the exercise tend to occur with activities lasting from 60 to 240 s. Over that range, benefits decrease. Beta-alanine seems to help the most in exercises that induce intracellular acidosis and short high-intensity exercises like sprinting.
Sometimes people who use pre-workout supplements experience tingling feeling on the skin also known as acute paraesthesia (a sensation of uncomfortable pins and needles feeling). The reason for this side effect is still unknown, but most likely is caused because of the effect beta-alanine on the central nervous system. It is considered harmless and can be avoided by using a smaller dosage size of the supplement.
According to the stand of International Society of Sports Nutrition (ISSN), “daily supplementation with 4 to 6 g of beta-alanine for at least 2 to 4 weeks has been shown to improve exercise performance, with more pronounced effects in open end-point tasks/time trials lasting 1 to 4 min in duration”.
Beta-alanine occurs naturally in our central nervous system. Within the nervous system, it may act as a neurotransmitter and has binding sites in the brain (hippocampus) just like neurotransmitters GABA, glutamate, and glycine. That is why some authors suggest that beta-alanine should be categorized as a neurotransmitter. Studies on the impact of carnosine supplementation on brain’s health suggested that carnosine may have therapeutic relevance in neurodegenerative diseases like Alzheimer’s disease, Parkinson’s disease, epilepsy, and brain injury. For example, ROS (reactive oxygen species), copper and zinc ions, glycating agents, protein cross-linking may all contribute and are connected to Alzheimer’s disease. Because of its properties, carnosine shows therapeutic potential for the treatment of this disease (and other neurodegenerative disorders that are connected with oxidative stress). Studies have also suggested that a rise of carnosine levels (or related dipeptides) in the brain may improve cognitive function, memory and relieve fatigue symptoms.
One of the findings of the International society for sports nutrition related to supplementation with beta-alanine is also “beta-alanine attenuates neuromuscular fatigue, particularly in older subjects”. A study from 2017 supports the conclusion: supplementation with beta-alanine showed an anti-fatigue effect in both men and women.
Carnosine possesses a great potential for improving language and behavior in children diagnosed with autistic spectrum disorders. A research from 2002 shows that taking carnosine 800 mg daily for 8 weeks may improve autism severity, behavior, socialization, communication, and vocabulary.
As supplementation with beta-alanine may improve athletic performance, it is often added to pre-workout products. People take beta-alanine before workout because it gives them a spike in energy and they can train harder and longer. A study from 2009 shown supplementation with beta-alanine may enhance high-intensity interval training, improving endurance performance and lean body mass in men. In another similar study with women, beta-alanine supplementation decreased body fat and increased fat-free mass during six weeks of high-intensity interval training.
Potential taurine deficiency
Taurine is an organic acid that contains sulfur. Taurine is widely distributed in tissue and has many roles in our bodies, such as antioxidation, osmoregulation, membrane stabilization and it is essential for the function of the cardiovascular and central nervous system. In theory, beta-alanine supplementation can cause a potential decrease in taurine concentrations. This is because beta-alanine and taurine share the same transporter into muscle, and beta-alanine could potentially inhibit taurine uptake within the muscle. But there is not enough evidence to support decreases of taurine concentration during beta-alanine supplementation in human. It seems that beta-alanine is safe for use in healthy individuals at recommended doses.
However, the possibility that supplementation with beta-alanine could lead to taurine deficiency cannot be completely ruled out, simply because more research should be done on this topic.
My experience with beta-alanine
From personal experience, I can say beta-alanine really gives a boost in energy before workouts. My muscles recover much faster after exercise, too. I have also noticed I am more focused.
Because vegans and strict vegetarians are prone to be deficient in this amino acid, I think supplementation with beta-alanine would be beneficial for them. For vegans, it is good to know that nowadays one can find carnosine and beta-alanine supplements without the use of animal muscles/tissues.