Moderate-to-heavy habitual alcohol use appears to be detrimentally associated with inflammation even when accounting for diet quality in humans: findings from an observational intensive longitudinal study

AIMS: This study investigated the associations between diet quality and daily alcohol use across 21 days with inflammation in adults with overweight/obesity. METHODS: This secondary analysis, from an observational intensive longitudinal study, investigated associations between alcohol use and inflammation. Adults 21-44 years old with a body mass index ≥ 25 kg/m2 (n = 91) participated in a 21-day study with daily measures of past-day alcohol use and baseline and follow-up measures of dietary intake (automated self-administered 24-hour recall, ASA-24). Healthy Eating Index (HEI)-2015 scores assessed diet quality. Follow-up blood draws assessed C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). Models investigated associations between diet quality (HEI total score or whole grains and saturated fat) and alcohol use [average and variability in drinks per day or drinker type (nondrinker, light, moderate, or heavy drinker)] with inflammation, accounting for percentage body fat, smoking, and sex. Moderation by sex was also tested. RESULTS: Average drinks per day and variability in drinks per day were not associated with inflammation. Moderate- and heavy-drinking females had 1.27 and 1.38 mg/l higher CRP than light-drinking females, with no differences in males. Heavy-drinking adults had 2.54 pg/ml higher TNF-α than light drinkers. Sex moderated the association between drinker type and IL-6 (b = 1.26, P = .035); however, there were no significant pairwise differences. Drinker type was not associated with IL-1β. CONCLUSIONS: These findings suggest that moderate-to-heavy alcohol use may be detrimentally associated with inflammation regardless of diet quality, suggesting that a high-quality diet may be insufficient to protect against the harmful effects of alcohol use on inflammation.