BACKGROUND The fatty acid (FA) composition of blood can be used as an objective biomarker of dietary FA intake. It remains unclear how the nutritional state influences the FA composition of plasma lipid fractions, and thus their usefulness as biomarkers in a non-fasted state. OBJECTIVES To investigate the associations between palmitate, oleate and linoleate in plasma lipid fractions and self-reported dietary FA intake, and assess the influence of meal consumption on the relative abundance of these FA in plasma lipid fractions (i.e. triglyceride [TG], phospholipids [PLs] and cholesterol esters [CEs]). DESIGN Analysis was performed in plasma samples collected from 49 (34 males and 15 females) participants aged 26-57 years with a body mass index (BMI) between 21.6 and 34.2 kg/m2, all of whom had participated in multiple study visits, thus a pooled cohort of 98 data sets was available for analysis. A subset (n = 25) had undergone nutritional interventions and was therefore used to investigate the relationship between the FA composition of plasma lipid fractions and dietary fat intake. RESULTS Significant (P < 0.05) positive associations were observed between dietary polyunsaturated fat and linoleate abundance in plasma CE. When investigating the influence of meal consumption on postprandial FA composition, we found plasma TG palmitate significantly (P < 0.05) decreased across the postprandial period, whereas oleate and linoleate increased. A similar pattern was observed in plasma PL, whereas linoleate abundance decreased in the plasma CE. CONCLUSION Our data demonstrate that the FA composition of plasma CE may be the lipid fraction to utilise as an objective biomarker when investigating recent (i.e. previous weeks-months) dietary FA intakes. In addition, we show that the consumption of a high-fat meal influences the FA composition of plasma TG, PL and CE over the course of the postprandial period, and therefore, suggest that fasting blood samples should be utilised when using FA composition as a biomarker of dietary FA intake.

中文翻译：

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营养状态对循环脂质组分脂肪酸组成的影响：对它们作为膳食脂肪摄入生物标志物的影响。

背景 血液中的脂肪酸（FA）成分可作为膳食 FA 摄入量的客观生物标志物。目前尚不清楚营养状态如何影响血浆脂质部分的 FA 组成，以及它们作为非禁食状态下生物标志物的有用性。目的 研究血浆脂质部分中棕榈酸酯、油酸酯和亚油酸酯与自我报告的膳食 FA 摄入量之间的关系，并评估膳食消耗对血浆脂质部分中这些 FA 相对丰度的影响（即甘油三酯 [TG]、磷脂 [...] PLs] 和胆固醇酯 [CEs])。设计分析从 49 名（34 名男性和 15 名女性）参与者收集的血浆样本中进行，这些参与者年龄在 26-57 岁之间，体重指数 (BMI) 在 21.6 和 34.2 kg/m2 之间，他们都参加了多次研究访问，因此，98 个数据集的集合队列可用于分析。一个子集（n = 25）接受了营养干预，因此用于研究血浆脂质部分的 FA 组成与膳食脂肪摄入量之间的关系。结果 在膳食多不饱和脂肪和血浆 CE 中亚油酸丰度之间观察到显着 (P < 0.05) 正相关。在调查膳食消耗对餐后 FA 组成的影响时，我们发现血浆 TG 棕榈酸酯在餐后期间显着降低（P < 0.05），而油酸和亚油酸增加。在血浆 PL 中观察到类似的模式，而在血浆 CE 中亚油酸丰度降低。结论 我们的数据表明，血浆 CE 的 FA 成分可能是在调查最近（即前几周 - 几个月）膳食 FA 摄入量时用作客观生物标志物的脂质部分。此外，我们发现高脂膳食的摄入会影响餐后期间血浆 TG、PL 和 CE 的 FA 组成，因此，建议在使用 FA 组成时应使用空腹血样膳食 FA 摄入量的生物标志物。