Article at a Glance:
- There are 20 amino acids and just under half of them cannot be made in the human body.
- Being deficient in one or multiple amino acids can lead to an array of short and long-term health complications.
- Each essential amino acid plays a role in key functions of the human body.
Amino acids are organic compounds that consist of both amino and acid groups which link together to form proteins. Proteins play a crucial role in muscle growth, repair, and maintenance. This makes amino acids an important part of the human diet.
There is a total of 20 amino acids but nine of them are considered to be essential. The nine essential amino acids must be resourced from the diet because the body cannot produce them on its own.
Why Amino Acids Are Important
Being deficient in essential amino acids can lead to problems like low appetite, issues with absorbing, transporting, and storing nutrients, emotional disorders, insomnia, anemia, and reduced transport of oxygen.
Some research also shows endocrine imbalance, skeletal muscle wasting, physical fatigue, libido loss, reduced fertility, and advanced aging to correlate with essential amino acid deficiencies.
To get enough of these amino acids, eating lean meats, fish, eggs, dairy, beans, and nuts is imperative. These essential amino acids can also be found in other plant-based foods like quinoa, soy, lentils, and seeds.
Because these amino acids are so prevalent and commonly known to be in meat products, it may take extra attention for people following vegan or vegetarian diets to get the ideal amount of them but it is possible.
Let’s chat about the nine essential amino acids and what they do for your body.
What Do Amino Acids Do?
Amino acids do a lot of things. As we already mentioned, they help to grow and repair muscles but they also make up many enzymes and hormones (such as insulin) which play an important role in things like metabolism and digestion.
Energy levels can also be impacted by amino acids as these compounds can be utilized for energy. This is especially true during prolonged exercising or when fasting. Amino acids also help produce antibodies and other immune cells that help to fight off infections and diseases within the body.
Brain functioning and mood can even be impacted by the intake, or lack thereof, of amino acids. This is because amino acids like tryptophan and tyrosine serve as precursors to serotonin and dopamine which are neurotransmitters that can affect how we feel, think, and the way we respond to situations.
The repair of damaged tissues and recovery from injuries and surgery are even impacted by amino acids. This is because the amino acids glutamine and arginine can help speed the processes of recovery and repair up. Glutamine also plays a role in gut function because it can help maintain the integrity of the gut lining, meaning that leaky gut syndrome is less likely to occur.
The 9 Essential Amino Acids
Leucine
This essential amino acid (EAA) is responsible for the stimulation of muscle protein synthesis. Meaning, it’s super important when it comes to helping muscles grow and recover. Leucine also helps regulate blood sugar levels and how your energy is metabolized. Additionally, leucine also helps in the repair of wounds.
Tryptophan
You might consider this EAA the “feel-good” one because it is a precursor to serotonin. Why is serotonin so important you ask? It’s important because it helps regulate mood, sleep, and appetite. Tryptophan is helpful in the production of melatonin which helps with sleep regulation.
On top of all that, it also plays a role in immune function and niacin production, also known as vitamin B3. Basically, if you want to feel happy and rested then you definitely want to make sure you are getting enough of this EAA.
Lysine
Collagen plays an important role in keeping our skin, bones, and connective tissue healthy and lysine is essential for collagen production. It also plays a part in calcium absorption (which is crucial for bone health) and immune function. Lysine also helps prevent and treat nuisances like cold sores.
Valine
Another EAA essential for proper muscle growth and repair is valine. It also aids in energy production, mental focus, and stress management. This EAA works hand in hand with leucine and isoleucine as a branched-chain amino acid, better known as a BCAA.
Valine is important for post-exercise muscle repair, reduction of soreness, and speeding up the workout recovery process.
Isoleucine
Another BCAA, isoleucine, is important for regulating the energy level within muscle cells as well as supporting muscle tissue repair and growth post-workout. It also helps to prevent muscle breakdown, also known as catabolism.
One extra important function of this EAA is that it is essential for red blood cell production and red blood cells play the role of transporting oxygen throughout the body.
Leucine
The final EAA of the BCAA trio, leucine is responsible for the activation of the mTOR pathway switch and stimulates muscle protein synthesis.
Basically, this amino acid is extra important when it comes to building and repairing muscle tissue which tends to make it one that athletes focus heavily on consuming.
Leucine is also used by muscles as an energy source during long bouts of exercise. Plus, it works to preserve muscle glycogen stores so that the onset of fatigue can be delayed when exercising. Glucose uptake into cells is also aided by leucine.
Histidine
You’ve probably heard of histamine but what about histidine? Histidine actually is converted into histamine within the body and is a big player in immune response as well as inflammation and allergic reactions. It also plays a role in the regulation of stomach acid production and digestion.
This EAA in particular is crucial when it comes to nerve function. This is because it forms part of myelin sheaths which help to protect and insulate nerve fibers within the body and also make sure nerves function properly.
Phenylalanine
Brain functioning, mood regulation, and pain management are heavily impacted by this EAA. There are 3 types of phenylalanine: L-phenylalanine, D-phenylalanine, and DL-phenylalanine.
- L-phenylalanine is naturally occurring in food and aids in protein synthesis while
- D-phenylalanine is synthetic and known for having potential pain-relieving properties.
- DL-phenylalanine is a mix of natural and synthetic phenylalanine and is often used in mood and pain relief supplements.
Phenylalanine gets converted to tyrosine which aids in the production of the feel-good hormones and neurotransmitters: dopamine, epinephrine, and norepinephrine. All of these play key roles in mood, motivation, and stress response.
Threonine
Collagen and elastin production depend on threonine and these two things help to maintain skin elasticity, healthy joints, and the ability to efficiently heal wounds. Maintaining desired levels of threonine can even help to prevent skin aging due to its ability to help keep your connective tissues strong and flexible.
This EAA also plays a key role in gut health because it’s found in mucins which protect the lining of your intestines and digestive tract. Keeping the lining of your digestive system strong and healthy promotes proper digestion which is a key component of long-term health. Threonine also helps produce antibodies and plays a role in neurotransmitter balance.
Methionine
This EAA is incredibly important for cellular protection and liver function. This is because it’s a precursor to cysteine and glutathione, two powerful antioxidants. It also helps produce creatine which plays an important role in muscle energy and performance.
As far as methionine’s role in liver function, it aids in the breakdown of fats which is helpful in preventing fatty liver disease and it helps to remove toxins like heavy metals from the body. It even plays a part in cardiovascular health because it helps regulate homocysteine levels which are linked to heart disease when an excess amount is present.
LiveComplete Takeaways
The nine essential amino acids play a key role in many human body functions. It’s important to get plenty of these amino acids through your diet due to your body’s inability to make them on their own. Many animal and plant-based foods contain these essential amino acids but people following a plant-based diet may need to place extra focus on their EAA intake.
Sources:
- Hou, Y., & Wu, G. (2018). Nutritionally essential amino acids. https://www.sciencedirect.com/science/article/pii/S216183132201273X
- Soeters, P. B. (2020). Vegan diets: what is the benefit? https://journals.lww.com/co-clinicalnutrition/citation/2020/03000/editorial__vegan_diets__what_is_the_benefit_.17.aspx
- Xiao, F., & Guo, F. (2022). Impacts of essential amino acids on energy balance. https://www.sciencedirect.com/science/article/pii/S2212877821002489
