Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, AZ, USA.
Center for Alaska Native Health Research, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.
J Nutr. 2023 Jan 14;152(12):2847-2855. doi: 10.1093/jn/nxac213.
Molecular stable isotope ratios are a novel type of dietary biomarker with high sensitivity and specificity for certain foods. Among these, fatty acid carbon isotope ratios (CIRs) have strong potential but have not been investigated as dietary biomarkers.
We evaluated whether fatty acid CIRs and mass proportions were associated with meat, fish, and sugar-sweetened beverage (SSB) intake.
Thirty-two men [aged 46.2 ± 10.5 y; BMI (kg/m2): 27.2 ± 4.0] underwent a 12-wk inpatient dietary intervention at the National Institute of Diabetes and Digestive and Kidney Diseases in Phoenix, Arizona. Men were randomly assigned to 1 of 8 dietary treatments varying the presence/absence of dietary meat, fish, and SSBs in all combinations. Fatty acid CIRs and mass proportions were measured in fasting blood samples and adipose tissue biopsies that were collected pre- and postintervention. Dietary effects were analyzed using multivariable regression and receiver operating characteristic AUCs were calculated using logistic regression.
CIRs of the several abundant SFAs, MUFAs and arachidonic acid (20:4n-6) in plasma were strongly associated with meat, as were a subset of these fatty acids in RBCs. Effect sizes in plasma ranged from 1.01‰ to 1.93‰ and were similar but attenuated in RBCs. Mass proportions of those fatty acids were not associated with diet. CIRs of plasma dihomo-γ-linolenic acid (20:3n-6) and adipose palmitic acid (16:0) were weakly associated with SSBs. Mass proportions of plasma odd-chain fatty acids were associated with meat, and mass proportions of plasma EPA and DHA (20:5n-3 and 22:6n-3) were associated with fish.
CIRs of plasma and RBC fatty acids show promise as sensitive and specific measures of dietary meat. These provide different information from that provided by fatty acid mass proportions, and are informative where mass proportion is not. This trial is registered at www.clinicaltrials.gov as NCT01237093.
分子稳定同位素比值是一种新型的饮食生物标志物，对某些食物具有高度的敏感性和特异性。其中，脂肪酸的碳同位素比值（CIRs）具有很强的潜力，但尚未作为饮食生物标志物进行研究。
我们评估了脂肪酸 CIRs 和质量比例与肉类、鱼类和含糖饮料（SSB）摄入的相关性。
32 名男性[年龄 46.2±10.5 岁；BMI（kg/m2）：27.2±4.0]在亚利桑那州凤凰城的国家糖尿病、消化和肾脏疾病研究所进行了为期 12 周的住院饮食干预。男性被随机分配到 8 种饮食处理中的 1 种，这些处理在所有组合中都存在或不存在饮食中的肉类、鱼类和 SSB。在干预前后采集空腹血样和脂肪组织活检，以测量脂肪酸 CIRs 和质量比例。使用多变量回归分析饮食效果，并使用逻辑回归计算接收者操作特征曲线下面积（AUC）。
血浆中几种丰富的 SFAs、MUFA 和花生四烯酸（20:4n-6）的 CIRs 与肉类密切相关，红细胞中也存在这些脂肪酸的一部分。血浆中这些脂肪酸的效应大小范围为 1.01‰至 1.93‰，在红细胞中相似但减弱。这些脂肪酸的质量比例与饮食无关。血浆中二高-γ-亚麻酸（20:3n-6）和脂肪棕榈酸（16:0）的 CIRs 与 SSB 弱相关。血浆中奇数链脂肪酸的质量比例与肉类有关，而 EPA 和 DHA（20:5n-3 和 22:6n-3）的质量比例与鱼类有关。
血浆和 RBC 脂肪酸的 CIRs 作为饮食中肉类的敏感和特异性指标具有很大的潜力。这些指标提供了与脂肪酸质量比例不同的信息，在质量比例无法提供信息时，这些指标具有指示性。本试验在 www.clinicaltrials.gov 注册，编号为 NCT01237093。
