Effects of diets high in unsaturated Fatty acids on socially induced stress responses in Guinea pigs

PLoS One. 2014 Dec 31;9(12):e116292. doi: 10.1371/journal.pone.0116292. eCollection 2014.

Abstract

Unsaturated fatty acids (UFAs), such as omega-3 and omega-6 poly- and omega-9 monounsaturated fatty acids are important nutrients and major components of neuronal cell membranes. They play a major role in modulating brain functions and physiology and may therefore diminish behavioral and physiological stress reactions in corroboration with decreased cortisol concentrations. Functionally, cortisol itself can modulate several behaviors and also the fatty acid metabolism in the long term. But only little is known about the behavioral and physiological influences of dietary UFAs in a social group, where individuals are regularly exposed to stressful situations. Therefore, the aim of this study was to determine the effects of dietary UFAs on saliva cortisol concentrations and behavioral responses in socially confronted guinea pigs. Three groups of animals were additionally supplemented with 500 mg chia seeds (high in omega-3), walnuts (high in omega-6), or peanuts (high in omega-9) per kg bodyweight each day and compared to a control group. During social confrontation saliva cortisol concentrations significantly increased in all groups, which was accompanied by a loss in bodyweight. However, cortisol levels remained lower in the chia and walnut groups compared to controls. Additionally, the walnut group displayed significantly increased locomotion, while no differences between groups were detected in socio-positive, sexual, or aggressive behaviors. Total plasma omega-3, omega-6, and omega-9 fatty acids were significantly increased in the corresponding groups, due to the dietary supplementations. However, a significant decrease in plasma omega-3 and an increase in plasma n-6 fatty acids were detected in the chia group when comparing the measurements before and after social confrontation. We conclude that both omega-3 and omega-6 polyunsaturated fatty acids can diminish behavioral and physiological stress responses to the social environment, enabling individuals to cope with social stressors, but at the expense of plasma derived omega-3 fatty acids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Weight
  • Diet Therapy
  • Fatty Acids, Omega-3 / pharmacology
  • Fatty Acids, Omega-6 / pharmacology
  • Fatty Acids, Unsaturated / pharmacology*
  • Female
  • Guinea Pigs
  • Hydrocortisone / metabolism*
  • Lipid Metabolism
  • Male
  • Saliva / chemistry
  • Social Behavior
  • Stress, Physiological / drug effects*

Substances

  • Fatty Acids, Omega-3
  • Fatty Acids, Omega-6
  • Fatty Acids, Unsaturated
  • Hydrocortisone

Grants and funding

This study was part of an “intrafaculty networks” research activity by the departments of Behavioural Biology, Anthropology, and Nutritional Sciences, funded by the dean's office of the faculty of life sciences, University of Vienna. This article was supported by the Open Access Publishing Fund of the University of Vienna. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.