Consumption of snacks rich in dietary fibre, particularly from konjac or agar powder, helps relieve constipation in older adults without affecting their energy intake, a Vietnam study has shown.
“Fiber-rich snacks formulated with konjac or agar powder demonstrated effectiveness in alleviating constipation in the elderly [population] without significantly altering energy intake,” the researchers said.
Twenty elderly residents with constipation at Tuyet Thai Nursing Home in Vietnam (11 women, mean age 77 years; nine men, mean age 79 years) were included in this 3-week crossover study. Participants were divided into groups receiving either control or fibre-rich snacks in alternating weeks, with a washout week in between. Two snacks were given per day: control snack made with tapioca and gelatine and intervention snack made with konjac (≈3 g fibre) and agar (≈3 g fibre).
The researchers collected data on stool status, dietary intake, and quality of life (as assessed by the Patient Assessment of Constipation Quality of Life questionnaire).
Stool frequency was higher during the intervention vs control period (4.9 vs 3.3 times/week). The proportion of bowel movements with normal stool form also rose from 35 percent to 85 percent, with a reduction in stool constipation form from 56 percent to 14 percent (p<0.05). [Asia Pac J Clin Nutr 2026;35:656-665]
Energy intake did not significantly differ between the two periods, but fibre intake substantially improved during intervention (11.8 vs 6.1 g/day). The difference in fibre intake between periods reached statistical significance (p<0.05), but the difference in energy intake did not (p>0.05).
Quality of life
Furthermore, intake of fibre-rich snacks resulted in a better quality of life (QoL) among participants. During the control period, the QoL scores increased from 81 to 90, but during the intervention period, the scores increased from 83 to 105.
These results support those of previous studies reporting enhanced QoL following improvements in constipation. [Aliment Pharmacol Ther 2016;44:35-44]
“However, the magnitude of improvement observed in the current study appears to be greater than that reported in some previous studies,” the researchers said. “It also emphasizes that choosing a healthy and appropriate diet will contribute to improving the QoL of older people.” [https://www.mdpi.com/2072-6643/10/8/971 doi:10.3390/nu100809]
Furthermore, potential bias and measurement error related to self-reported outcomes must be taken into account, according to the researchers. Participant-reported diaries and questionnaires, which were used to assess stool frequency and QoL, may be prone to recall bias, reporting bias, and variability in individual interpretation.
“Although participants were provided with standardized instructions to record their outcomes, some degree of measurement error cannot be excluded,” the researchers said.
Role of fibre
The findings of the current study highlight the role of fibre in diet, which plays an important role in maintaining healthy digestive function. Fibre has two main types, soluble and insoluble, and each type has a different mechanism of action and effects on the digestive system. [https://www.sciencedirect.com/science/article/pii/B9780128051306000033 doi:10.1016/B978-0-12-805130-6.00003-3]
“When soluble fibre enters the body, it can dissolve in water to form a gel, helping to retain water in the intestines, soften stools, and promote the movement of stools through the colon,” the researchers said.
“Insoluble fibre does not dissolve in water and has the effect of increasing stool volume. [I]t stimulates intestinal motility, increasing the speed of stool movement through the intestines,” they added.
“In fibre-rich snacks, glucomannan and agar are two types of fibre, which explains the improved stool frequency and structure. And softer stools help reduce the burning sensation in the anus when defecating,” according to the researchers.