Association Between Caffeine Intake and Stool Frequency- or Consistency-Defined Constipation: Data From the National Health and Nutrition Examination Survey 2005-2010.

Abstract

Background/aims: The association between caffeine intake and constipation remains inconclusive. This study aims to investigate whether caffeine intake is associated with constipation.

Methods: This cross-sectional study included 13 941 adults from the 2005-2010 National Health and Nutrition Examination Survey. The weighted logistic regression analyses were exerted to evaluate the association between caffeine intake and constipation. Besides, stratified analyses and interaction tests were conducted to determine the potential modifying factors.

Results: After adjusting for confounders, increased caffeine intake by 100 mg was not associated with constipation, as defined by stool frequency (OR, 1.01; 95% CI, 0.94-1.10) or stool consistency (OR, 1.01; 95% CI, 0.98-1.05). Subgroup analyses showed that cholesterol intake modified the relationship between increased caffeine by 100 mg and stool frequency-defined constipation (P for interaction = 0.037). Each 100 mg increase in caffeine intake was associated with a 20% decreased risk of constipation defined by stool frequency in participants who consumed high cholesterol (OR, 0.80; 95% CI, 0.64-1.00), but no association in the other 2 cholesterol level groups. Furthermore, the association between caffeine intake and stool consistency-defined constipation was not found in different cholesterol groups.

Conclusions: Caffeine consumption is not associated with stool frequency or consistency-defined constipation. Nevertheless, increased caffeine intake may decrease the risk of constipation (defined by stool frequency) among participants in the high-cholesterol intake group.