Cancer Prevention and Control Program, University of South Carolina, 915 Greene Street, Suite 200, Columbia, SC 29208, United States; Department of Epidemiology and Biostatistics, University of South Carolina, 915 Greene Street, Suite 200, Columbia, SC 29208, United States; Connecting Health Innovations, LLC, 915 Greene Street, Suite 200, Columbia, SC 29208, United States.
Department of Epidemiology and Biostatistics, University of South Carolina, 915 Greene Street, Suite 200, Columbia, SC 29208, United States.
Brain Behav Immun. 2018 Mar;69:296-303. doi: 10.1016/j.bbi.2017.12.003. Epub 2017 Dec 5.
White blood cells (WBCs) are considered a reliable biomarker of inflammation. Elevations in both WBCs and pro-inflammatory cytokines are associated with several chronic conditions. Diet is a strong moderator of inflammation and WBCs. The purpose of this study was to examine the association between the Dietary Inflammatory Index (DII®) and WBCs using data from the United States National Health and Nutrition Examination Survey (NHANES). NHANES is a cross-sectional study that occurs in two-year cycles. Respondents from five cycles (n = 26,046) with available data on diet (collected through a single 24-h dietary recall [24HR]) and WBCs (derived using the Coulter method) were included. The DII (theoretical range is about -8 to +8) was derived from the micro and macronutrients calculated from the 24HR. Linear regression models, using survey design procedures, were used to estimate adjusted mean WBC (i.e., total, lymphocytes, monocytes, and neutrophils) counts and percentages by DII quartiles. Among all participants no statistically significant difference in WBCs were observed when comparing DII quartile 4 (most pro-inflammatory) to quartile 1 (most anti-inflammatory). However, a one-unit increase in the DII was associated with a 0.028 (1000 per µL) increase in total WBCs (p = .01). Additionally, a 0.024 increase in neutrophils (p < .01) was observed for a one-unit increase in the DII. In the group of participants with normal body mass index (BMI, 18.5-24.9 kg/m), those in DII quartile 4 had higher levels of total WBCs compared to subjects with normal BMI in DII quartile 1 (7.12 vs. 6.88, p = .01). Similar comparisons were observed for monocytes and neutrophils. However, these relationships were not observed for participants who were overweight or obese, which are pro-inflammatory conditions. Normal-weight individuals consuming more pro-inflammatory diets were more likely to have elevated WBCs. Because of its cross-sectional design, NHANES cannot inform directly on temporal relations, thus limiting causal inference. Future research is needed to examine the impact of anti-inflammatory diet adoption on lowering levels of WBCs, in addition to other inflammatory mediators.
白细胞（WBC）被认为是炎症的可靠生物标志物。WBC 和促炎细胞因子的升高与几种慢性疾病有关。饮食是炎症和 WBC 的重要调节剂。本研究的目的是使用美国国家健康和营养检查调查（NHANES）的数据，研究饮食炎症指数（DII®）与 WBC 之间的关系。NHANES 是一项在两年周期中进行的横断面研究。纳入了来自五个周期（n=26046）的应答者，这些周期有饮食数据（通过单次 24 小时饮食回忆[24HR]收集）和 WBC 数据（使用库尔特法得出）。DII（理论范围约为-8 到+8）是根据 24HR 计算得出的微量和宏量营养素得出的。使用调查设计程序的线性回归模型，根据 DII 四分位数估计调整后的平均 WBC（即总、淋巴细胞、单核细胞和中性粒细胞）计数和百分比。在所有参与者中，比较 DII 四分位数 4（最促炎）和四分位数 1（最抗炎）时，WBC 无统计学差异。然而，DII 增加一个单位与总 WBC 增加 0.028（1000 个/µL）（p=0.01）相关。此外，DII 增加一个单位与中性粒细胞增加 0.024（p<0.01）相关。在正常体重指数（BMI，18.5-24.9kg/m）的参与者中，与 BMI 正常的 DII 四分位数 1 组相比，DII 四分位数 4 组的总 WBC 水平更高（7.12 比 6.88，p=0.01）。对于单核细胞和中性粒细胞也观察到类似的比较。然而，对于超重或肥胖的参与者，这些关系并不存在，超重或肥胖是促炎状态。摄入更多促炎饮食的正常体重个体更有可能出现 WBC 升高。由于其横断面设计，NHANES 不能直接提供关于时间关系的信息，因此限制了因果推断。需要进一步研究采用抗炎饮食对降低 WBC 水平以及其他炎症介质的影响。
