Fowler Lauren A, Dennis-Cornelius Lacey N, Dawson John A, Barry Robert J, Davis James L, Powell Mickie L, Yuan Yuan, Williams Michael B, Makowsky Robert, D'Abramo Louis R, Watts Stephen A
Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA.
Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
Curr Dev Nutr. 2020 Mar 19;4(4):nzaa034. doi: 10.1093/cdn/nzaa034. eCollection 2020 Apr.
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.
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.
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 ( = 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).
Dietary lipid and sex interacted in their effects on body weight ( = 0.015), total body length ( = 0.003), and total lipid mass ( = 0.029); thus, these analyses were stratified by sex. Female spawning success decreased as dietary total lipid and fatty acid ratio increased ( = 0.030 and = 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); < 0.001].
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.
关于n-6（ω-6）与n-3（ω-3）脂肪酸比例对肥胖和健康的影响，在人类和动物研究中均有相互矛盾的发现。两个混杂因素可能与其他膳食脂质成分的相互作用或脂肪酸代谢中的性别差异有关。
本研究调查了总膳食脂质、n-6与n-3脂肪酸比例以及性别对野生型斑马鱼生长、肥胖和生殖健康的主要及交互作用。
将3周龄的雄性和雌性斑马鱼喂食9种饲料，这些饲料由3种n-6与n-3脂肪酸比例（1.4:1、5:1和9.5:1）组成，且在3种总脂质含量（80、110和140 g/kg）范围内变化，持续16周。然后收集关于生长、身体组成（通过化学胴体分析确定）和雌性生殖成功率的数据（4周内每种饲料有32次繁殖事件）。采用回归方法评估膳食脂质和性别的主要及交互作用。每种膳食脂质成分内的显著差异相对于截距/参考组（80 g/kg和1.4:1比例）。
膳食脂质和性别在对体重（P = 0.015）、全长（P = 0.003）和总脂质质量（P = 0.029）的影响上存在交互作用；因此，这些分析按性别分层进行。随着膳食总脂质和脂肪酸比例增加雌性产卵成功率下降（分别为P = 0.030和P = 0.026）。虽然总产卵量与任何一种膳食脂质成分均无关联，但喂食5:1比例的雌性与1.4:1比例相比产生更高比例的可存活胚胎[中位数（95% CI）：0.915（0.863，0.956）对0.819（0.716，0.876）；P < 0.001]。
进一步明确膳食脂质需求特征将有助于确定膳食脂质的健康平衡，而本研究中确定的对膳食脂质的性别特异性反应可能部分解释肥胖及其合并症发生发展中的性别差异。
