Both Dietary Ratio of n-6 to n-3 Fatty Acids and Total Dietary Lipid Are Positively Associated with Adiposity and Reproductive Health in Zebrafish

Lauren A Fowler; Lacey N Dennis-Cornelius; John A Dawson; Robert J Barry; James L Davis; Mickie L Powell; Yuan Yuan; Michael B Williams; Robert Makowsky; Louis R D'Abramo; Stephen A Watts

doi:10.1093/cdn/nzaa034

Both Dietary Ratio of n-6 to n-3 Fatty Acids and Total Dietary Lipid Are Positively Associated with Adiposity and Reproductive Health in Zebrafish

Curr Dev Nutr. 2020 Mar 19;4(4):nzaa034. doi: 10.1093/cdn/nzaa034. eCollection 2020 Apr.

Authors

Lauren A Fowler^{1

2}, Lacey N Dennis-Cornelius², John A Dawson^{1

3}, Robert J Barry², James L Davis², Mickie L Powell^{1

2}, Yuan Yuan², Michael B Williams², Robert Makowsky⁴, Louis R D'Abramo², Stephen A Watts^{1

2}

Affiliations

¹ Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA.
² Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
³ Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA.
⁴ Almac Diagnostics, Durham, NC, USA.

Abstract

Background: Controversial findings have been reported in human and animal studies regarding the influence of n-6 (ω-6) to n-3 (ω-3) fatty acid ratios on obesity and health. Two confounding factors may be related to interactions with other dietary lipid components or sex-specific differences in fatty acid metabolism.

Objective: This study investigated main and interactive effects of total dietary lipid, ratio of n-6 to n-3 fatty acids, and sex on growth, adiposity, and reproductive health in wild-type zebrafish.

Methods: Male and female zebrafish (3 wk old) were fed 9 diets consisting of 3 ratios of n-6 to n-3 fatty acids (1.4:1, 5:1, and 9.5:1) varied within 3 total lipid amounts (80, 110, and 140 g/kg) for 16 wk. Data were then collected on growth, body composition (determined by chemical carcass analysis), and female reproductive success (n = 32 breeding events/diet over 4 wk). Main and interactive effects of dietary lipid and sex were evaluated with regression methods. Significant differences within each dietary lipid component were relative to the intercept/reference group (80 g/kg and 1.4:1 ratio).

Results: Dietary lipid and sex interacted in their effects on body weight (P = 0.015), total body length (P = 0.003), and total lipid mass (P = 0.029); thus, these analyses were stratified by sex. Female spawning success decreased as dietary total lipid and fatty acid ratio increased (P = 0.030 and P = 0.026, respectively). While total egg production was not associated with either dietary lipid component, females fed the 5:1 ratio produced higher proportions of viable embryos compared with the 1.4:1 ratio [median (95% CI): 0.915 (0.863, 0.956) vs 0.819 (0.716, 0.876); P < 0.001].

Conclusions: Further characterization of dietary lipid requirements will help define healthy balances of dietary lipid, while the sex-specific responses to dietary lipid identified in this study may partially explain sex disparities in the development of obesity and its comorbidities.

Keywords: body composition; diet-induced obesity; dietary lipid composition; reproductive health; zebrafish.

Abstract

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