每日食用苹果可降低超重和肥胖成年人的血浆和外周血单个核细胞分泌的炎症生物标志物：一项为期 6 周的随机、对照、平行臂试验。

Daily apple consumption reduces plasma and peripheral blood mononuclear cell-secreted inflammatory biomarkers in adults with overweight and obesity: a 6-week randomized, controlled, parallel-arm trial.

机构信息

Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.

出版信息

Am J Clin Nutr. 2021 Aug 2;114(2):752-763. doi: 10.1093/ajcn/nqab094.

DOI:10.1093/ajcn/nqab094

PMID:33964852

Abstract

BACKGROUND

Obesity-associated low-grade inflammation contributes to the development of cardiovascular disease (CVD). Apples are rich in anti-inflammatory bioactives including polyphenols and fiber.

OBJECTIVES

We aimed to determine the effects of regular apple consumption on fasting plasma biomarkers of inflammation (primary outcome), endotoxemia, carbohydrate and lipid metabolism (glucose, insulin, triacylglycerol; secondary outcomes), and peripheral blood mononuclear cell (PBMC)-secreted cytokines (secondary outcome) in individuals with overweight and obesity.

METHODS

A randomized, controlled, parallel-arm trial was conducted with n = 46 participants. After avoiding foods and beverages rich in polyphenols and fiber for 2 wk, participants consumed 3 whole Gala apples (∼200 g edible parts)/d as part of their habitual diet (n = 23) or avoided apples (control, n = 23) for 6 wk. All participants limited consumption of polyphenols and fiber during the 6-wk trial. Fasting blood samples were collected before and after 6 wk for analysis of plasma biomarkers and isolation of PBMCs, which were cultured for 24 h unstimulated or stimulated with LPS (10 ng/mL).

RESULTS

Forty-four participants completed the trial (30 female, 14 male; mean ± SEM age: 45.4 ± 2.2 y; BMI: 33.4 ± 0.9 kg/m2). After ANCOVA and correcting for multiple comparisons, apples decreased fasting plasma C-reactive protein by 17.0% (range: 14.3%-19.6%, P = 0.005), IL-6 by 12.4% (range: 6.7%-17.5%, P < 0.001), and LPS-binding protein by 20.7% (range: 14.1%-26.4%, P < 0.001) compared with control. Apples also decreased PBMC-secreted IL-6 by 28.3% (range: 22.4%-33.5%, P < 0.001) and IL-17 by 11.0% (range 5.8-15.6%, P = 0.003) in the unstimulated condition compared with control. Exploratory analysis showed apples also increased plasma total antioxidant capacity by 9.6% (range: 1.7-18.9%, P = 0.002) compared with control. However, apples had no effect on anthropometric or other CVD risk markers.

CONCLUSIONS

Six-week daily whole Gala apple consumption may be an effective dietary strategy to mitigate the obesity-associated inflammation that exacerbates CVD risk, without weight loss. This trial was registered at clinicaltrials.gov as NCT03523403.

摘要

背景

肥胖相关的低度炎症会导致心血管疾病（CVD）的发生。苹果富含具有抗炎作用的生物活性物质，包括多酚和纤维。

目的

本研究旨在确定经常食用苹果对超重和肥胖个体空腹血浆炎症生物标志物（主要结局）、内毒素血症、碳水化合物和脂质代谢（血糖、胰岛素、三酰甘油；次要结局）以及外周血单个核细胞（PBMC）分泌的细胞因子（次要结局）的影响。

方法

采用随机、对照、平行臂试验，纳入了 46 名参与者。在避免食用富含多酚和纤维的食物和饮料 2 周后，23 名参与者将 3 个 Gala 苹果（约 200 g 可食用部分）作为其日常饮食的一部分（干预组），23 名参与者避免食用苹果（对照组），持续 6 周。在 6 周的试验期间，所有参与者都限制了多酚和纤维的摄入量。在 6 周前后采集空腹血样，用于分析血浆生物标志物和分离 PBMC，将 PBMC 在未刺激或用 LPS（10 ng/mL）刺激 24 小时后进行培养。

结果

44 名参与者完成了试验（30 名女性，14 名男性；平均年龄 ± 标准差：45.4 ± 2.2 岁；BMI：33.4 ± 0.9 kg/m2）。经协方差分析（ANCOVA）和多重比较校正后，与对照组相比，苹果使空腹血浆 C 反应蛋白降低了 17.0%（范围：14.3%-19.6%，P=0.005）、白细胞介素 6（IL-6）降低了 12.4%（范围：6.7%-17.5%，P<0.001）和脂多糖结合蛋白（LPS 结合蛋白）降低了 20.7%（范围：14.1%-26.4%，P<0.001）。与对照组相比，苹果还使 PBMC 分泌的白细胞介素 6 降低了 28.3%（范围：22.4%-33.5%，P<0.001）和白细胞介素 17（IL-17）降低了 11.0%（范围：5.8%-15.6%，P=0.003）。探索性分析显示，与对照组相比，苹果还使血浆总抗氧化能力增加了 9.6%（范围：1.7-18.9%，P=0.002）。然而，苹果对人体测量或其他 CVD 风险标志物没有影响。