Department of Nutrition, School of Public Health, University of Sao Paulo, Sao Paulo, Brazil.
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil.
Eur J Nutr. 2018 Dec;57(8):2887-2895. doi: 10.1007/s00394-017-1559-z. Epub 2017 Nov 2.
Inflammation plays a key role in the development of insulin resistance and atherosclerosis. Fatty acids and fiber intake can selectively alter gene expression by modifying inflammation.
We compared the postprandial expression of inflammatory genes after 2 distinct high-fat breakfast meals, before and after 1-month dietary interventions.
This crossover clinical trial included 18 individuals at low-to-moderate cardiometabolic risk participating in evaluations before and after two 4-week breakfast interventions-one rich in saturated fatty acids (SFA) and the other in unsaturated fatty acids (unSFA) and fiber. Participants underwent meal tests with similar compositions to the breakfasts. Variables were compared by Student t test. The expression of inflammatory genes in leukocytes was analyzed using RT-PCR.
Before and after the intervention with the SFA-enriched breakfast, this meal test induced a higher relative postprandial IL-1β expression compared to the responses to the unSFA and fiber-enriched meal (p = 0.02). On the other hand, following the intervention with the unSFA-fiber-enriched breakfast, postprandial IL-6 expression showed a reduction tendency comparing to the pre-intervention value (p = 0.08). Although fasting IL-1β, IL-6, MCP-1 and IFN-γ expressions had not changed after interventions, their circulating levels increased after the SFA-enriched meal test but not after the unSFA meal (p value between changes < 0.05).
Our findings indicated that a single SFA-enriched meal is able to acutely induce the IL-1β expression and regularly consumed could trigger systemic inflammation, while increased unSFA consumption could attenuate the inflammatory status. Further investigations are needed to deepen understanding how dietary fatty acids and fiber influence cardiometabolic risk profile by modulating inflammatory gene expression and circulating biomarkers.
This study is registered at the Brazilian Registry of Clinical Trials (ReBEC ID: RBR-98x6b5). Available at: http://www.ensaiosclinicos.gov.br .
炎症在胰岛素抵抗和动脉粥样硬化的发展中起着关键作用。脂肪酸和膳食纤维的摄入可以通过改变炎症来选择性地改变基因表达。
我们比较了两种不同高脂肪早餐餐后炎症基因的餐后表达，在 1 个月的饮食干预前后。
这项交叉临床试验包括 18 名低至中度心血管代谢风险的个体，在接受两种 4 周早餐干预前后进行评估，一种富含饱和脂肪酸（SFA），另一种富含不饱和脂肪酸（unSFA）和纤维。参与者接受了与早餐相似组成的膳食测试。通过学生 t 检验比较变量。使用 RT-PCR 分析白细胞中炎症基因的表达。
在富含 SFA 的早餐干预前后，与富含 unSFA 和纤维的膳食相比，这种膳食测试诱导的餐后 IL-1β 表达更高（p=0.02）。另一方面，在富含 unSFA-纤维的早餐干预后，与干预前相比，餐后 IL-6 表达呈下降趋势（p=0.08）。尽管干预后空腹 IL-1β、IL-6、MCP-1 和 IFN-γ 的表达没有变化，但在富含 SFA 的膳食测试后，它们的循环水平增加，但在富含 unSFA 的膳食后没有增加（变化之间的 p 值<0.05）。
我们的研究结果表明，单一富含 SFA 的膳食能够急性诱导 IL-1β 的表达，经常食用可能会引发全身炎症，而增加 unSFA 的摄入可以减轻炎症状态。需要进一步的研究来深入了解膳食脂肪酸和膳食纤维如何通过调节炎症基因表达和循环生物标志物来影响心血管代谢风险状况。
本研究在巴西临床试验注册处（ReBEC ID：RBR-98x6b5）注册。可在以下网址获得：http://www.ensaiosclinicos.gov.br 。
