Khodarahmi Mahdieh, Tabrizi Fatemeh Pourteymour Fard, Askari Gholamreza
Nutrition and Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
Nutrition Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
BMC Nutr. 2025 Apr 14;11(1):76. doi: 10.1186/s40795-025-01062-w.
Low-carbohydrate diets (LCDs) have been associated with inflammation while there is still conflicting evidence regarding the effects of this type of diet on inflammatory markers and the clinical benefit of them remains uncertain. So, we aimed to ascertain the effects of LCDs on serum concentrations of tumor necrosis factor alpha (TNF-α) and interleukin- 6 (IL- 6) by performing a systematic review and meta-analysis of randomized clinical trials (RCTs).
The online databases PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, Web of Science, and Scopus were comprehensively searched up to February 2024, to find pertinent RCTs. Pooled weighted mean difference (WMD) with 95% confidence intervals (CIs) were calculated using the random-effects model.
This meta-analysis of 33 studies assessed a total of 2106 adults irrespective of their health status. Compared with control group, participants on LCDs experienced a decline in IL- 6 levels (WMD: - 0.31 pg/mL; 95% CI: - 0.49 to - 0.12; P = 0.001). However, no significant effect was revealed for TNF-α (WMD: - 0.02 pg/mL; 95% CI: - 0.08 to - 0.03; P = 0.449). Stratification analyses indicated that beneficial effects of LCDs on inflammatory cytokines (WMD: - 0.28 pg/mL; 95% CI: - 0.47 to - 0.10; P = 0.003, WMD: - 0.26 pg/mL; 95% CI: - 0.48 to - 0.03; P = 0.027, for TNF-α and IL- 6, respectively) were stronger when carbohydrate intake was < 10%. The results of Meta-regression analyses suggested that baseline level of both markers remained as a strong predictor of the effect size (P = 0.038 and P = 0.001 for TNF-α and IL- 6, respectively).
Adherence to LCDs appeared to be effective at improving inflammatory cytokines particularly, when carbohydrate intake was restricted to less than 10% of total energy. Nevertheless, further rigorously designed clinical trials considering factors such as race and genetic, the sources and quality of dietary carbohydrates, protein, and fat are required to gain a deeper understanding of the impact of LCDs on inflammatory markers.
PROSPERO, registration no: CRD42023387452.
低碳水化合物饮食（LCDs）与炎症有关，然而关于这类饮食对炎症标志物的影响仍存在相互矛盾的证据，其临床益处也尚不确定。因此，我们旨在通过对随机临床试验（RCTs）进行系统评价和荟萃分析，以确定低碳水化合物饮食对血清肿瘤坏死因子α（TNF-α）和白细胞介素-6（IL-6）浓度的影响。
全面检索了截至2024年2月的在线数据库PubMed、Cochrane对照试验中央注册库（CENTRAL）、EMBASE、科学网和Scopus，以查找相关的随机对照试验。使用随机效应模型计算合并加权平均差（WMD）及95%置信区间（CIs）。
这项对33项研究的荟萃分析共评估了2106名成年人，无论其健康状况如何。与对照组相比，采用低碳水化合物饮食的参与者IL-6水平有所下降（WMD：-0.31 pg/mL；95% CI：-0.49至-0.12；P = 0.001）。然而，未发现对TNF-α有显著影响（WMD：-0.02 pg/mL；95% CI：-0.08至-0.03；P = 0.449）。分层分析表明，当碳水化合物摄入量<10%时，低碳水化合物饮食对炎症细胞因子的有益影响更强（TNF-α和IL-6的WMD分别为-0.28 pg/mL；95% CI：-0.47至-0.10；P = 0.003，-0.26 pg/mL；95% CI：-0.48至-0.03；P = 0.027）。Meta回归分析结果表明，两种标志物的基线水平仍然是效应大小的有力预测指标（TNF-α和IL-6分别为P = 0.038和P = 0.001）。
坚持低碳水化合物饮食似乎对改善炎症细胞因子有效，尤其是当碳水化合物摄入量限制在总能量的10%以下时。然而，需要进一步设计严谨的临床试验，考虑种族和基因、膳食碳水化合物、蛋白质和脂肪的来源及质量等因素，以更深入了解低碳水化合物饮食对炎症标志物的影响。
PROSPERO，注册号：CRD42023387452。
