Inflammatory diet ups risk of constipation

Individuals with a high inflammatory diet are at increased risk of constipation, suggests a study. Moreover, gender and physical activity may influence such relationship.

A total of 8,272 individuals (mean age 48.0 years, 47.8 percent female) were included in this analysis, of whom 759 (9.2 percent) reported constipation, while the rest (n=7,513, 90.8 percent) did not. [J Clin Gastroenterol 2025;59:648-653]

Compared with lower Dietary Inflammatory Index (DII) scores tertile (T)1 (–5.28 to ≤0.72), T2 (>0.72 to ≤2.50) and T3 (>2.50 to 5.24) demonstrated greater odds for constipation (T2: odds ratio [OR], 1.27, 95 percent confidence interval [CI], 1.02–1.58; p=0.029; T3: OR, 1.43, 95 percent CI, 1.14–1.8; p=0.002).

In the subgroup with high DII scores (>2.50 to 5.24), women showed higher DII scores than men (61.3 percent vs 38.7 percent). 

Moreover, DII scores were greater among non-Hispanic Whites, married, middle-income, highly educated, alcohol drinkers, and those who exercised ≥150 min per week. DII scores also differed from those with cardiovascular disease, hypertension, diabetes, stroke, constipation, and the use of selective serotonin reuptake inhibitors.

“The results of the study showed a significant correlation between DII scores and the risk of constipation in different DII subgroups after adjusting for multifactorial modelling,” the researchers said. “The tertile analysis showed that the third tertile of DII consumption was associated with a 43-percent increase in the odds of constipation compared to the first tertile of DII consumption.”

Gut flora

These findings support those from previous research. For instance, one study showed an association between the prevalence of constipation and mortality from chronic disease as DII scores increased. [Eur J Nutr 2022;61:341-355]

In another study, an association was found between the inflammatory potential of the diet and the abundance of gut flora in patients with constipation. [Ann Epidemiol 2022;75:39-46]

The present study, on the other hand, used data from NHANES focused on the relationship between the DII and constipation, with adjustments for potential confounders. The results confirmed the increased risk for constipation with increasing DII scores. This association persisted in subgroup analyses.

Treatment

Constipation can be treated using several approaches, including diet modification, changes in lifestyle habits, and use of medications. [Mayo Clin Proc 2019;94:2340-2357; Dig Dis Basel Switz 2022;40:175-180

“Although altering dietary structure and composition is considered to be the first step in the treatment of constipation, food composition has an important influence on the distribution of intestinal flora, intestinal mucosal function, and intestinal motility function,” the researchers said. [Adv Nutr Bethesda Md 2017;8:484-494; Nutrients 2022;14:3704]

The current cross-sectional study used data from adult participants in the 2005 to 2010 NHANES and identified cases of constipation via self-reported information.

The researchers used DII to assess the inflammatory potential of the diet. They also calculated the ORs and corresponding 95 percent CIs using multivariate logistic regression modeling. Finally, stratified analyses were conducted to determine whether there was effect modification to influence the association between DII and constipation.

“DII is the primary indicator for assessing inflammatory components in food, and elevated scores have been associated with the occurrence of chronic constipation in the gut,” the researchers said.