Dietary Inflammatory Index Is Associated With Inflammation in Japanese Men
Ayaka Kotemori, Norie Sawada, Motoki Iwasaki, Taiki Yamaji, Nitin Shivappa, James R. Hébert, Junko Ishihara, Manami Inoue, Shoichiro Tsugane
Abstract
Background: Dietary components are known to affect chronic low-grade inflammation status. The dietary inflammatory index (DII®) was developed to measure the potential impact of a diet on an individual's inflammatory status, and it has been validated mainly in Western countries. Objective: This study aimed to examine the validity of the energy-adjusted DII (E-DII TM ) using high-sensitivity C-reactive protein (hs-CRP) concentration in Japanese men and women. Methods: In total, 6,474 volunteers from a cancer-screening program (3,825 men and 2,649 women) completed a food frequency questionnaire (FFQ) and their hs-CRP concentrations were evaluated. E-DII scores were calculated on the basis of 30 food parameters derived from the FFQ. Higher E-DII scores reflect a greater pro-inflammatory potential of the diet. The associations between E-DII quartiles and hs-CRP concentration were assessed using regression models adjusted for age, body mass index, smoking status, and amount of physical activity. Results: Mean E-DII in men and women was + 0.62 ± 1.93 and −1.01 ± 2.25, respectively. The proportion of men and women who had hs-CRP concentration >3 mg/L was 4.7 and 3.1%, respectively. A significant positive association was observed between E-DII score and hs-CRP concentration in men; geometric mean of hs-CRP concentration in the lowest and highest E-DII quartiles was 0.56 mg/L and 0.67 mg/L ( P trend < 0.01), respectively. The odds ratio (95% confidence interval) of having an elevated hs-CRP concentration (>3 mg/L) was 1.72 (1.10–2.67) in the highest E-DII quartile ( P trend = 0.03) in men. However, no association was observed between E-DII score and hs-CRP concentration in women, except in those not taking prescription medications. Conclusions: DII was associated with inflammation status in Japanese men, but the association was limited in Japanese women.