About the Importance of Amino Acids and Protein
Life on Earth is varied, but although there are about 500 naturally occurring amino acids, every living organism on earth forms its proteins from the same set of 22 amino acids. So, it is not just a phrase to say that amino acids are the building blocks of life. Amino acids can be combined to complex macromolecules, so-called proteins. Proteins not only catalyze all (or almost all) of the chemical reactions in living cells, they control virtually all cellular process. In addition, proteins provide many of the structural elements of a cell and help to connect cells to tissues.
Types of Amino Acids
Nutritionists classify amino acids based on a variety of features, including whether people must acquire them through diet. Accordingly, amino acids can be classified into the following three types:
• Essential amino acids: Though all 21 proteinogenic amino acids are important for our health, only nine amino acids are classified as essential. Unlike fat and starch, the human body does not store excess amino acids for later use, so these essential amino acids must be supplied through food. Essential amino acids are lysine, methionine, histidine, leucine, isoleucine, phenylalanine, threonine, valine and tryptophan.
• Nonessential amino acids: These amino acids do not have to be provided by the diet. They can be synthesized by our organism from other amino acids or from other molecules of the intermediate metabolism.
• Conditionally essential amino acids: There are several nonessential amino acids that are considered conditionally essential. Under certain conditions, their requirement may exceed the body's own synthesis, e.g. under certain diseases or in premature infants. Conditional amino acids include alanine, aspartic acid, asparagine, glutamic acid, serine and selenocysteine.**
Amino Acids and their Function in the Body
When we eat food that contains protein, our digestive system breaks it down into individual amino acids. Once the amino acids have been absorbed, they are released into the bloodstream and transported to cells in other parts of the human organism where they can be reassembled into proteins and other biomolecules that the body needs. Proteins have a specific role in our body – some proteins more than one. Here are some examples:
• Structural proteins maintain cell shape and build up structural elements in connective tissues like cartilage and bone. These proteins are also particularly important for the muscular system since they contribute to both increase and maintenance of muscle mass as well as supporting essential regenerative processes.
• Enzymes are another type of protein that significantly speed up all chemical reactions that occur within cells. Without them, many reactions would happen too slowly to support our life.
• Hormone proteins are chemical messengers that regulate the activity of cells or organs.
• Transport proteins bind and carry atoms and small molecules across biological membranes and throughout the body.
• Antibodies are produced by the immune system in response to the presence of a foreign substance. These protective proteins help remove foreign substances and fight infections.
• Contractile proteins are needed for muscle contraction and movement.
Protein in the Diet
When it comes to protein in the diet, quality is more important than quantity. “Complete proteins” (or: “whole proteins”) are the highest quality of proteins and contain the full range of essential amino acids. High-quality protein sources include chicken, turkey, beef, pork, fish, eggs, pea protein and soybeans. You might notice that most of the high value options are from animal sources. This is simply because the pattern of amino acids in animal cells mimics the composition in human cells. But plant-based eaters don’t have to worry about their protein intake. Although most plant-based proteins are not complete, you can mix up different types (e.g. lentils, chickpeas, kidney beans, oat, almonds, walnuts) to make a total package. Like a jigsaw, our organism will “piece together” the various proteins from everything we eat in a day.
Amino Acids – It’s All About the Package
When we eat protein-rich foods, we also eat other nutrients and substances that come alongside it: vitamins, minerals, fiber, different fats, and more. So, it’s the package that makes a difference for good health. Accordingly, choose protein sources that are nutrient-rich and lower in saturated fat and calories, such as nuts, seeds, beans or fish.**
About Amino Acids Supplements
Amino acids have been offered for many years as dietary supplements in the US and other countries worldwide. These supplements can provide a balanced ratio of essential amino acids (e.g. in the case of increased need) or they can help to achieve a higher intake of certain amino acids to address specific health concerns. However, as with any dietary supplement, you should consult your doctor before taking any high concentrated amino acid products, especially if you are pregnant or taking any medication.**
Tip: If you are interested in more in-depth information on amino acids, you can use the online tool www.micronutrientscoach.com
Amino Acids – What are the Recommendations?
The National Academy of Medicine recommends that adults get 0.8 grams of protein for every kilogram of body weight per day. Because of their rapid growth, infants have the highest needs for protein at 1.5 grams of protein for every kilogram of body weight per day. The ideal amount of protein in the diet increases also during pregnancy and lactation to a level of 1.1 g/kg.
- Hou Y, Wu G. Nutritionally Essential Amino Acids. Adv Nutr. 2018 Nov 1;9(6):849-851. Havard: https://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/protein/, Zugriff: 18.11.2019
- British Nutrition Foundation: https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/protein.html?limitstart=0 , Zugriff: 18.11.2019
- U.S. Department of Argriculture: https://www.nal.usda.gov/sites/default/files/fnic_uploads/energy_full_report.pdf, Zugriff: 18.11.2019
** These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.