Health benefits and risks of plant proteins

Bratisl Lek Listy. 2005;106(6-7):231-4.


Plant proteins have a reduced content of essential amino acids in comparison to animal proteins. A significant reduction of limiting amino acids (methionine, lysine, tryptophan) means lower protein synthesis. In subjects with predominant or exclusive consumption of plant food a higher incidence of hypoproteinemia due to significant reduction of methionine and lysine intakes was observed. On the other hand, lower intake of these amino acids provides a preventive effect against cardiovascular disease via cholesterol regulation by an inhibited hepatic phospholipid metabolism. Vegetarians have a significantly higher intake of non-essential amino acids arginine and pyruvigenic amino acids glycine, alanine, serine. When plant protein is high in non-essential amino acids, down-regulation of insulin and up-regulation of glucagon is a logical consequence. The action of glucagon in the liver is mediated by stimulation of adenyl cyclase that raises cyclic-AMP (adenosine-3,5-monophosphate) concentrations. Cyclic-AMP down-regulates the synthesis of a number of enzymes required for de novo lipogenesis and cholesterol synthesis, up-regulates key gluconeogenic enzymes and the LDL receptors and decreases the IGF-1 activity (insulin-like growth factor). Cyclic-AMP thus provides a reduction of atherosclerosis risk factors as well as a retardation of cancer development. A sufficient consumption of plant proteins has the protective effects against chronic degenerative diseases (Tab. 2, Ref. 26).

Publication types

  • Review

MeSH terms

  • Amino Acids, Essential / administration & dosage
  • Cardiovascular Diseases / prevention & control
  • Diet, Vegetarian* / adverse effects
  • Dietary Proteins / administration & dosage*
  • Plant Proteins / administration & dosage*
  • Plant Proteins, Dietary


  • Amino Acids, Essential
  • Dietary Proteins
  • Plant Proteins
  • Plant Proteins, Dietary