Association of Dietary Inflammatory Index with Serum IL-6, IL-10, and CRP Concentration during Pregnancy

Background: The mother's diet has a direct impact on fetal development and pregnancy, and can also be important in the course of the body's inflammatory response. An anti-inflammatory diet can be a promising way to counter an excessive inflammatory response in pregnancy. Objective: The aim of the study was to examine the association between the dietary inflammatory index (DII) and the pregnant women's serum interleukin 6 (IL-6) and 10 (IL-10) and C-reactive protein (CRP) concentration in the course of normal and complicated pregnancy. Research Methods and Procedures: The study included 45 Polish pregnant women recruited to the study. The DII, a literature-based dietary index to assess the inflammatory properties of diet, was estimated based on a seven-day 24-h recall and an food frequency questionnaire (FFQ) in each trimester of pregnancy. At the same time as the nutritional interviews, blood samples were collected for the determination of IL-6, IL-10, and CRP concentrations. The studied group was divided into subgroups with normal and complicated pregnancy and depending on the DII median. Results: With the development of pregnancy, the DII score slightly decreased in subsequent trimesters: -1.78 in the first trimester, -2.43 in the second trimester, and -2.71 in the third trimester (p = 0.092). Independent of the trimester of pregnancy and the occurrence of pregnancy complications, the DII score did not affect the differences in the serum concentrations of IL-6, IL-10, and CRP, with the exception of CRP level in the second trimester in women with complicated pregnancy (subgroup with DII < median had a lower CRP level than subgroup with DII > median). In the first and third trimesters, there was a weak but significant positive correlation between the DII score and CRP concentration. During the second trimester, in the group with normal pregnancy and DII below the median, a significant negative correlation between the DII score and the serum IL-6 and IL-10 concentration was noted as well as in the third trimester for IL-6. Conclusion: The anti-inflammatory potential of a pregnant woman's diet increases slightly with pregnancy development; however, its value has no permanent significant association with the level of CRP, IL-6, and IL-10.