The Association between Dietary Fiber Intake and CRP levels, US Adults, 2007–2010

Abstract

BackgroundThe 2015 Dietary Guidelines for Americans Committee highlight dietary fiber as one of the four nutrients that Americans under‐consumed. Data from the National Health and Nutrition Examination Survey 1999–2000 on dietary fiber demonstrated a strong inverse relation between the level of dietary fiber intake and C‐reactive protein, but did not analyze specific sources nor the strength of the effect according to the dietary fiber source.ObjectiveTo determine the relationship between C‐reactive protein (CRP) levels and dietary fiber sources in the US adult population (≥ 20 years of age).DesignIn the 2007–2010 National Health and Nutrition Examination Survey, a cross‐sectional nationally representative sample of the US population, two 24 hour dietary recalls were collected from 9,720 adults 20 years and older. Of those that had both 24 hour recalls, 9,284 adults had CRP data. We categorized CRP into 3 levels, < 0.10 mg/dL, 0.10 mg/dL≤CRP< 0.30 mg/dL, ≥ 0.30 mg/dL. The relationship between CRP levels and total fiber intake as well as the sources of dietary fiber including whole grain intake and fruit and vegetable intake were examined by using multinomial logistic models adjusted for age, sex, race, BMI and smoking.ResultsAdults with lowest quartile of dietary fiber intake compared to the highest quartile were 50% more likely to have higher CRP levels (OR: 1.47; 95% CI: 1.28, 1.68). Similarly, the lowest quartile of whole grain intake compared to the highest quartile was 40% more likely to have higher CRP levels (OR: 1.40; 95% CI: 1.19, 1.65). In addition, the lowest quartile of fiber rich fruit and vegetable intake compared to the highest quartile was 50% more likely to have higher CRP levels (OR: 1.51; 95% CI: 1.27, 1.79).ConclusionsWe found an inverse relationship between CRP levels and dietary fiber consumption. High whole grain, and high fruit and vegetable intake were associated with low C‐reactive protein levels, a marker of systemic inflammation.