N-3 fatty acids reduced trans fatty acids retention and increased docosahexaenoic acid levels in the brain

Abstract

Introduction: The levels of docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) are critical for the normal structure and function of the brain. Trans fatty acids (TFA) and the source of the dietary fatty acids (FA) interfere with long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis.

Objectives: The aim of this study was to investigate the effect of TFA supplementation in diets containing different proportions of n-9, n-6, and n-3 FA on the brain FA profile, including the retention of TFA, LC-PUFA levels, and n-6/n-3 PUFA ratios. These parameters were also investigated in the liver, considering that LC-PUFA are mainly bioconverted from their dietary precursors in this tissue and transported by serum to the brain. Also, stearoyl-CoA desaturase-1 (SCD1) and sterol regulatory element-binding protein-1c (SREBP-1c) gene expressions were evaluated.

Methods: Male CF1 mice were fed (16 weeks) diets containing different oils (olive, corn, and rapeseed) with distinct proportions of n-9, n-6, and n-3 FA (55.2/17.2/0.7, 32.0/51.3/0.9, and 61.1/18.4/8.6), respectively, substituted or not with 0.75% of TFA. FA composition of the brain, liver, and serum was assessed by gas chromatography.

Results: TFA were incorporated into, and therefore retained in the brain, liver, and serum. However, the magnitude of retention was dependent on the tissue and type of isomer. In the brain, total TFA retention was lower than 1% in all diets.

Discussion: Dietary n-3 PUFA decreased TFA retention and increased DHA accretion in the brain. The results underscore the importance of the type of dietary FA on the retention of TFA in the brain and also on the changes of the FA profile.

Keywords:

• Trans fatty acids
• Brain
• Fatty acids profile
• Olive oil
• Rapeseed oil
• Corn oil
• Long-chain polyunsaturated fatty acids

Acknowledgements

We wish to thanks Walter DaRú for his technical assistance. We also thanks the financial support received from Universidad Nacional del Litoral-Cursos de Acción para la Investigación y Desarrollo (CAI+D 2011 PI-501 201101 00166 LI)-Secretaría de Ciencia y Técnica – UNL.

Disclaimer statements

Contributor Marcela Aida González and Claudio Bernal were responsible for the overall conception and design of the study, data handling, and interpretation. Jimena Lavandera collaborated in the generation, collection, analysis, and interpretation of data. These three authors were responsible for writing the article in whole. Juliana Saín and Ana Clara Fariña participated in the analysis and interpretation of data related to fatty acid profile and in the revising the article.

Funding None.

Conflict of interest The authors have no conflicts of interest to declare.

Ethics approval The animals used in these studies were maintained humanely in compliance with the guidelines established by the Animal Care and Use Committee of the Argentine Association of Specialists in Laboratory Animals (AADEALC). Moreover, Institution Ethic Committee has approved the corresponding research project.