Person:

Tabung, Fred

Background/objective The dietary inflammatory index (DII) measured at one time point is associated with risk of several chronic diseases but disease risk may change with longitudinal changes in DII scores. Data are lacking regarding changes in DII scores over time, therefore we assessed changes in the DII in the Women's Health Initiative (WHI). Methods: DII scores were calculated using data from repeated food frequency questionnaires in the WHI Observational Study (OS; n=76,671) at baseline and Year 3, and the WHI Dietary Modification trial (DM; n=48,482) at three time points. Lower DII scores represent more anti-inflammatory diets. We used generalized estimating equations to compare mean changes in DII over time, adjusting for multiple comparisons; and multivariable linear regression to determine predictors of DII change. Results: In the OS, mean DII decreased modestly from −1.14 at baseline to −1.50 at Year 3. In the DM, DII was −1.32 in Year 1, −1.60 in Year 3, and −1.48 in Year 6 in the intervention arm, and was −0.65 in Year 1, −0.94 in Year 3 and −0.96 in Year 6 in the control arm. These changes were modified by BMI, education, and race/ethnicity. A prediction model explained 22% of the variance in the change in DII scores in the OS. Conclusion: In this prospective investigation of postmenopausal women, reported dietary inflammatory potential decreased modestly over time. Largest reductions were observed in normal weight, highly educated women. Future research is warranted to examine whether reductions in DII are associated with decreased chronic disease risk.

Background: Diet modulates inflammation and inflammatory markers have been associated with cancer outcomes. In the Women's Health Initiative, we investigated associations between a dietary inflammatory index (DII) and invasive breast cancer incidence and death. Methods: The DII was calculated from a baseline food frequency questionnaire in 122 788 postmenopausal women, enrolled from 1993 to 1998 with no prior cancer, and followed until 29 August 2014. With median follow-up of 16.02 years, there were 7495 breast cancer cases and 667 breast cancer deaths. We used Cox regression to estimate multivariable-adjusted hazards ratios (HRs) and 95% confidence intervals (95% CIs) by DII quintiles (Q) for incidence of overall breast cancer, breast cancer subtypes, and deaths from breast cancer. The lowest quintile (representing the most anti-inflammatory diet) was the reference. Results: The DII was not associated with incidence of overall breast cancer (HRQ5vsQ1, 0.99; 95% CI, 0.91–1.07; Ptrend=0.83 for overall breast cancer). In a full cohort analysis, a higher risk of death from breast cancer was associated with consumption of more pro-inflammatory diets at baseline, after controlling for multiple potential confounders (HRQ5vsQ1, 1.33; 95% CI, 1.01–1.76; Ptrend=0.03). Conclusions: Future studies are needed to examine the inflammatory potential of post-diagnosis diet given the suggestion from the current study that dietary inflammatory potential before diagnosis is related to breast cancer death.

Background: Specific foods and nutrients, including alcohol, may contribute to gut barrier dysfunction. However, to our knowledge, the influence of whole diets is currently unknown. Objective: We aimed to cross-sectionally investigate associations of dietary patterns with plasma soluble CD14 (sCD14), which is released by macrophages on stimulation with endotoxin and has been used as a marker of gut hyperpermeability. Methods: We used food-frequency questionnaire data collected from 689 women in the Nurses’ Health Study and 509 men in the Health Professionals Follow-Up Study. Our principal component analysis identified 2 dietary patterns: “Western” (higher intakes of red meat, processed meat, desserts, and refined grains) and “prudent” (higher intakes of fruits, vegetables, fish, and whole grains). In multivariable-adjusted logistic regression analyses, we estimated ORs and 95% CIs for high (equal to or greater than the median compared with less than the median) sCD14 concentrations in quintiles of each dietary pattern. Using logistic regression, we also investigated the joint association of the Western dietary pattern and alcohol intake or C-reactive protein (CRP) with sCD14 concentrations. Results: Western dietary pattern scores were positively associated with sCD14 concentrations (OR: 1.86; 95% CI: 1.24, 2.79; P-trend = 0.0005; comparing extreme quintiles). Analyses of joint associations suggested that the strongest associations with higher sCD14 concentrations were for persons with both high Western pattern scores and high alcohol intake compared with participants with low scores for both (OR: 2.96; 95% CI: 1.61, 5.45) or for participants with both high Western pattern scores and high CRP values compared with those with low scores for both (OR: 4.11; 95% CI: 2.57, 6.58). The prudent pattern was not associated with sCD14 concentrations. Conclusions: Higher consumption of the Western dietary pattern is associated with a marker of macrophage activation and gut hyperpermeability, especially when coupled with high alcohol intake and heightened systemic inflammation. Our findings need confirmation in studies with additional markers of gut barrier dysfunction.

Multiple dietary patterns have been associated with different diseases; however, their comparability to improve overall health is yet to be determined. In 205,852 healthcare professionals from three US cohorts followed for up to 32 years, we prospectively assessed two mechanism-based diets and six diets based on dietary recommendations in relation to major chronic disease, defined as a composite outcome of incident major cardiovascular disease, type 2 diabetes, and cancer. We demonstrated that adherence to a healthy diet was generally associated with a lower risk of major chronic disease (hazard ratio [HR] comparing the 90th to 10th percentile of dietary pattern scores: 0.58–0.80). Participants with low insulinemic (HR 0.58, 95% CI 0.57, 0.60), low inflammatory (HR 0.61, 95% CI 0.60, 0.63), or diabetes risk-reducing diet (HR 0.70, 95% CI 0.69, 0.72) had the largest risk reduction for incident major cardiovascular disease, type 2 diabetes, and cancer in composite and individually. Similar findings were observed across sex, and diverse ethnic groups. Our results suggest that dietary patterns that are associated with markers of hyperinsulinemia and inflammation and diabetes development may inform on future dietary guidelines for chronic disease prevention.