Amino acids are essential to life. All living things contain organic compounds called amino acids that form chains. These chains are called proteins, which the body needs to complete various roles. Depending on the sequence of amino acids within each chain, these proteins perform different tasks. For example, some proteins break down food and generate energy. Other proteins maintain muscle mass, and muscle strength, and repair body tissue, as well as many other roles. Amino acid proteins improve your immunity and maintain healthy hair, nails, and skin. Their primary purpose is to support biological and psychological health. If our bodies lack amino acids, this deficiency can result in health issues such as a lower level of immunity and greater inflammation.
In simple terms, we need enough protein intake to neutralize the levels of nitrogen in our body’s system. This is referred to as the zero nitrogen balance. Our bodies need enough quantities of quality micronutrients to metabolise essential amino acids. Other lifestyle factors also influence the metabolism of amino acids. For example, physical activity, smoking, chemical or pollution exposure, alcohol consumption, or certain illnesses (i.e. tuberculosis, HIV, sepsis) can increase or decrease the levels of nitrogen in the body. Therefore, amino acid protein needs vary for each person. Our bodies naturally produce 11 different amino acids through a process known as biosynthesis. In addition, there are nine types of essential amino acids that our bodies cannot produce. Instead, we must get these essential amino acids from food.
The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. All these acids perform different but vital roles within our bodies. Essential amino acids are especially important in the production of neurotransmitters (brain chemicals) and hormones. For example, tryptophan is used in the production of serotonin, a neurotransmitter that regulates our appetite, sleep, and mood. Histidine contributes to the production of histamine, a neurotransmitter vital to our digestion, sleep, sexual function, and immune system. Phenylalanine is used to create dopamine, the ‘feel-good’ hormone that produces motivation and pleasure.
Studies show that the best way to meet your body’s needs for the nine essential amino acids is through a balanced nutritious diet. The most effective source of essential amino acids is dietary protein or animal fat. Examples include eggs, milk and dairy products, beef, fish, and poultry. Importantly, we need to consume quality protein (i.e. lean beef, free-range poultry). In plant-based diets, buckwheat, quinoa, and soy provide important sources of essential amino acids. You can also eat a variety of beans, nuts, and seeds to boost the level of essential amino acids in your diet. However, studies show that a plant-based diet provides fewer essential amino acids compared with a diet that includes animal proteins.
In some cases, taking amino acid supplements can be helpful. Supplements may support you during some life stages, such as pregnancy or older adulthood (65 years plus). Some diets may struggle to provide the daily intake of essential amino acids. For example, a recent study from Finland found that participants following a vegan diet had lower levels of essential amino acids compared with those who ate meat as a regular part of their diet. This occurred even though a nutritionist planned daily menus for the study period. Another observational study compared two groups of people following either a meat-based diet or non-meat (vegan) diet. They found that meat-based diets provided a higher source of essential amino acids, in particular histidine and lysine.
Regardless of what diet you follow, it is important to consult a healthcare professional before you begin taking any amino acid supplement. You can request blood tests to assess what your body needs. In addition, have a conversation about any diet or lifestyle factors and how these may impact your levels of amino acids.