Essential fabric

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An essential substance is a chemical compound (or a chemical element ) that is vital for an organism and that it cannot synthesize itself from other nutrients such as water , fats or amino acids .

This article only lists the substances that are essential for humans, other substances are essential for other species. Minerals, trace elements, almost all vitamins , several amino acids and some polyunsaturated fatty acids are essential for humans .

amino acids

The following L- amino acids are considered essential for humans and must therefore be consumed with food:

  1. Isoleucine
  2. Leucine
  3. Lysine
  4. Methionine
  5. Phenylalanine
  6. Threonine
  7. Tryptophan
  8. Valine
  9. Arginine (essential for children and old people, otherwise semi-essential)
  10. Histidine (essential for children)

Semi-essential (also conditionally essential) amino acids can be converted from other essential amino acids, but can become essential amino acids in certain phases of life or due to illnesses.

Fatty acids

Two fatty acids are essential for humans: linoleic acid (an omega-6 fatty acid ) and α-linolenic acid (an omega-3 fatty acid ). The body uses these to produce other fatty acids and secondary products ( eicosanoids ) it needs . These include arachidonic acid , eicosapentaenoic acid, and docosahexaenoic acid . Therefore, adding one or more of these secondary products reduces the need for the essential fatty acids. That may be the reason why the characterization “limited synthesizable” can occasionally be found in the literature in this context. However, a diet that has been free of arachidonic acid and eicosapentaenoic acid for years does not automatically lead to deficiency symptoms, while a deficiency in linolenic acid or linoleic acid leads to clear deficiency symptoms.

The metabolic pathways by which the important long-chain fatty acids are produced are influenced by various factors. B. excessive consumption of saturated or monounsaturated fatty acids or alcohol. An excess of omega-6 fatty acids hinders the processing of omega-3 fatty acids , as the enzymes responsible for this (elongase, delta-5 desaturase, delta-6 desaturase) process both substance classes.

The competitive inhibition also works in reverse, but a disproportion between omega-6 and omega-3 fatty acids is practically mostly on the side of omega-6 fatty acids, as these are usually contained in much larger proportions in food.

Minerals

Set elements

Trace elements

The essential trace elements are required by the organism in very small quantities and are often important for the action of special enzyme systems (e.g. with transaminases ).

Possibly essential trace elements

A biological function is only assumed for these elements, or the relationships and necessity have not yet been finally clarified.

Vitamins

By definition, all vitamins are essential. The human organism can only produce a limited amount of vitamin D from cholesterol through UV-B radiation , such as sunlight, and niacin (vitamin B3) from the essential amino acid tryptophan. Some vitamins can be absorbed in the form of precursors ( provitamins ), which can be converted into vitamins by the body itself. Others are the organism of symbiotic living organisms (eg. As intestinal bacteria found) are available, such as vitamin K . Vitamin B12, on the other hand, is only synthesized in the large intestine , so at this point it can no longer be absorbed by the small intestine and is therefore excreted again unused; therefore it must be ingested in sufficient quantities with food.

Essential substances in the animal kingdom

Ascorbic acid

Apart from humans, many monkeys and guinea pigs have a requirement for ascorbic acid (vitamin C) .

Choline

For some animals, dietary choline intake is essential. This is especially true for ruminants , as choline is almost completely broken down in the rumen . Choline is not a necessity for humans as long as their diet contains the amino acids methionine and folic acid .

Retinols

Retinols are sometimes ingested directly with food or formed from carotenes ( provitamin A ), also in humans, which not all animals are capable of (e.g. domestic cats ).

Taurine

In contrast to the human organism, cats are dependent on an external supply of taurine; Taurine is an essential amino sulfonic acid for your organism.

Individual evidence

  1. ↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 2: Cm-G. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1981, ISBN 3-440-04512-9 , p. 1184.
  2. ↑ Hans-Dieter Jakubke, Hans Jeschkeit: Amino acids, peptides, proteins. Verlag Chemie, Weinheim 1982, ISBN 3-527-25892-2 , pp. 23-26.
  3. ↑ "Semi-essential amino acids" in vitalstoff-lexikon.de , accessed on March 3, 2019
  4. ^ Brockhaus ABC chemistry. VEB F. A. Brockhaus Verlag, Leipzig 1965, p. 379.
  5. ^ S. Ebel, HJ Roth (Ed.): Lexicon of Pharmacy. Georg Thieme Verlag, 1987, ISBN 3-13-672201-9 , p. 605.
  6. ^ SH Zeisel, KA Da Costa, PD Franklin, EA Alexander, JT Lamont, NF Sheard, A. Beiser: Choline, an essential nutrient for humans. In: FASEB Journal. Volume 5, No. 7, 1991, pp. 2093-2098.
  7. ↑ FJ Schweigert, J. Raila, B. Wichert, E. Kienzle: Cats absorb beta-carotene, but it is not converted to vitamin A . In: J. Nutr. tape 132 , 6 Suppl 2, June 2002, p. 1610S-1612S , PMID 12042471 .
  8. ↑ Hans Lutz, Barbara Kohn, Franck Forterre: Diseases of the cat. Thieme, Stuttgart 2014, p. 45. (Restricted preview) .