Dietary fiber for constipation in older adults: a systematic review

Objective: The purpose of this systematic review is to describe and evaluate the quality and results of published trials of dietary fiber for constipation in older adults, and summarize the evidence for the effectiveness of this treatment.Methods: Published trials of dietary fiber treatment for constipation in older adults were included if they presented quantified outcomes for at least one measure of bowel function. Methodological quality was critically appraised according to defined criteria. The clinical results of randomized, controlled and/or double-blinded studies were analyzed and summarized.Results: Of 20 studies, 19 were conducted in institution-dwelling samples. Eight studies met review criteria. There were two double-blinded randomized controlled trials. Their results were contradictory. Declines in laxative use were observed in five of six studies, three of the five were unblinded. Contradictory results were reported for fecal incontinence and comfort with defecation.Conclusion: There is not strong or consistent evidence for the effectiveness of treating constipation in institution-dwelling older adults with dietary fiber. This is partly due to weak study design.