Amino Acids

, Volume 44, Issue 4, pp 1107–1113 | Cite as

Dietary requirements of “nutritionally non-essential amino acids” by animals and humans

  • Guoyao Wu
  • Zhenlong Wu
  • Zhaolai Dai
  • Ying Yang
  • Weiwei Wang
  • Chuang Liu
  • Bin Wang
  • Junjun Wang
  • Yulong Yin
Invited Review


Amino acids are necessary for the survival, growth, development, reproduction and health of all organisms. They were traditionally classified as nutritionally essential or non-essential for mammals, birds and fish based on nitrogen balance or growth. It was assumed that all “non-essential amino acids (NEAA)” were synthesized sufficiently in the body to meet the needs for maximal growth and health. However, there has been no compelling experimental evidence to support this assumption over the past century. NEAA (e.g., glutamine, glutamate, proline, glycine and arginine) play important roles in regulating gene expression, cell signaling, antioxidative responses, neurotransmission, and immunity. Additionally, glutamate, glutamine and aspartate are major metabolic fuels for the small intestine to maintain its digestive function and protect its mucosal integrity. Therefore, based on new research findings, NEAA should be taken into consideration in revising the classical “ideal protein” concept and formulating balanced diets to improve protein accretion, food efficiency, and health in animals and humans.


Amino acids Food efficiency Health Metabolism Nutrition 



Amino acids


AMP-activated protein kinase


Nutritionally essential amino acids


Eukaryotic translation initiation factor 4E-binding protein-1


Mechanistic target of rapamycin


Nutritionally non-essential amino acids


Nitric oxide


National Research Council



Work in our laboratories was supported by National Research Initiative Competitive Grants from the Animal Reproduction Program (2008-35203-19120) and Animal Growth and Nutrient Utilization Program (2008-35206-18764) of the USDA National Institute of Food and Agriculture, AHA (10GRNT4480020), Texas A&M AgriLife Research (H-8200), the National Natural Science Foundation of China (no. u0731001, 30810103902, 30928018, 30972156, 31172217 and 31272450), China Postdoctoral Science Foundation (2012T50163), Chinese Universities Scientific Funds (No. 2012RC024), and the Thousand-People Talent program at China Agricultural University. Important contributions of our graduate students and colleagues to the recent development of the field are gratefully appreciated.

Conflict of interest

The authors declare that they have no conflict of interests.


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Copyright information

© Springer-Verlag Wien 2012

Authors and Affiliations

  • Guoyao Wu
    • 1
    • 2
  • Zhenlong Wu
    • 1
    • 2
  • Zhaolai Dai
    • 1
    • 2
  • Ying Yang
    • 1
    • 2
  • Weiwei Wang
    • 1
    • 2
  • Chuang Liu
    • 2
  • Bin Wang
    • 2
  • Junjun Wang
    • 2
  • Yulong Yin
    • 3
  1. 1.Department of Animal ScienceTexas A&M UniversityCollege StationUSA
  2. 2.State Key Laboratory of Animal NutritionChina Agricultural UniversityBeijingChina
  3. 3.Laboratory of Animal Nutrition and Health and Key Laboratory of Agro-Ecology, Institute of Subtropical AgricultureThe Chinese Academy of Sciences, ChangshaHunanPeople’s Republic of China

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