Results Mean age of the women was 64±7 years, 85% were white and 2,937 (3.5%) experienced a kidney stone in a median followup of 8 years. In women with no history of kidney stones higher total dietary fiber (6% to 26% decreased risk, p <0.001), greater fruit intake (12% to 25% decreased risk, p <0.001) and greater vegetable intake (9% to 22% decreased risk, p=0.002) were associated with a decreased risk of incident kidney stone formation in separate adjusted models. In women with a history of stones there were no significant protective effects of fiber, fruit or vegetable intake on the risk of kidney stone recurrence.

Purpose: Many dietary factors have either proinflammatory or anti-inflammatory properties. We previously developed a dietary inflammatory index (DII) to assess the inflammatory potential of diet. In this study, we conducted a construct validation of the DII based on data from a food frequency questionnaire and three inflammatory biomarkers in a subsample of 2567 postmenopausal women in the Women's Health Initiative Observational Study. Methods: We used multiple linear and logistic regression models, controlling for potential confounders, to test whether baseline DII predicted concentrations of interleukin-6, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha receptor 2, or an overall biomarker score combining all three inflammatory biomarkers. Results: The DII was associated with the four biomarkers with beta estimates (95% confidence interval) comparing the highest with lowest DII quintiles as follows: interleukin-6: 1.26 (1.15-1.38), Ptrend < .0001; tumor necrosis factor alpha receptor 2: 81.43 (19.15-143.71), Ptrend=.004; dichotomized hs-CRP (odds ratio for higher vs. lower hs-CRP): 1.30 (0.97-1.67), Ptrend=.34; and the combined inflammatory biomarker score: 0.26 (0.12-0.40), Ptrend=.0001. Conclusions: The DII was significantly associated with inflammatory biomarkers. Construct validity of the DII indicates its utility for assessing the inflammatory potential of diet and for expanding its use to include associations with common chronic diseases in future studies.