Skip to main content

Serum amino acid concentrations in aging men and women


 The age and gender related differences in serum amino acid concentrations have been assessed in 72 (23–92 years) medically screened healthy men and women who were divided into three male and three female groups according to age. Free-time physical activity and food intake were analysed from the 5-day diaries. The subjects were instructed to eat according to their normal dietary habits and to avoid any clinical complementary nutritional products or other products that could increase protein or energy intake. The blood samples (5 ml) taken from the antecubital vein after an over-night fast were analysed for their amino acid contents by chromatography. In total nutrient intake of energy (P < 0.001), protein (P < 0.001), alcohol (P < 0.05), water (P < 0.01), sodium (P < 0.001) and fiber P < 0.001) decreased significantly with age. The concentration of total amino acids (P < 0.01), essential amino acids (P < 0.001), non-essential amino acids (P < 0.05) and branched-chain amino acids (P < 0.05) decreased, whereas citrulline (P < 0.001) and cysteine (P < 0.001) were the only amino acids, which increased with aging. In addition, men had significantly higher concentrations than women of essential amino acids (P < 0.001), branched-chain amino acids (P < 0.001), and 10 of the 22 individual amino acids assayed (P < 0.01). Women had significantly higher concentrations of aspartate (P < 0.05), glycine (P < 0.01), serine (P < 0.001) and taurine (P < 0.01) than men. It is concluded that the decrease in serum total amino acid concentration is associated with decreased energy and protein intake with aging and men have higher essential amino acid concentration in serum than women.

This is a preview of subscription content, access via your institution.

Author information

Authors and Affiliations


Additional information

Received April 20, 2002 Accepted August 17, 2002 Published online November 14, 2002

Acknowledgements The authors thank Ms. Paula Majanen and Ms. Raija Repo for the collection and analysis of blood samples and Mr. Hannu Tuuri for his help in statistical analysis.

Authors' address: Antti A. Mero, Department of Biology of Physical Activity, University of Jyväskylä, P.O. Box 35, 40351 Jyväskylä, Finland, E-mail:

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Pitkänen, H., Oja, S., Kemppainen, K. et al. Serum amino acid concentrations in aging men and women. Amino Acids 24, 413–421 (2003).

Download citation

  • Issue Date:

  • DOI:

  • Keywords: Amino acids
  • Non-athletes
  • Age
  • Gender
  • Nutrition