Mediterranean and plant-based diets can help prevent chronic constipation in aging adults – and surprisingly, the benefits weren’t explained by fiber alone. Western and inflammatory diets raised constipation risk, while low-carb diets showed minimal impact.

The research underscores how diet quality influences gut health well beyond traditional advice.

Researchers from Mass General Brigham, Boston, examined whether five widely followed diets could help prevent chronic constipation in middle- and older-age adults. The team monitored more than 96,000 participants for several years to see how long-term eating habits influenced the likelihood of developing this persistent gastrointestinal issue. Their analysis showed that people who routinely ate a Mediterranean or plant-based diet experienced a lower incidence of constipation.

Previous research has demonstrated that healthy diets can ease constipation symptoms, but this study is the first to show that some diets may actually prevent chronic constipation from developing, according to the authors, and that the benefit of the health diets on constipation were independent of fiber intake.

Using data from the Nurses' Health Study, Nurses' Health Study II and the Health Professionals Follow-Up Study, the investigators evaluated long-term dietary patterns in middle- and older-age adults and identified who later experienced chronic constipation, which was defined as symptoms lasting at least 12 weeks within a year.

They assessed five diets: the Mediterranean diet, plant-based diet, low-carb diet, Western diet, and inflammatory diet. Participants who consistently consumed a Western or inflammatory diet were more likely to develop chronic constipation, while those who followed a low-carb diet did not show a strong effect on constipation risk.

“Our findings suggest that dietary patterns emphasizing plant-based foods and healthy fats may protect against constipation, informing future dietary interventions and treatments for chronic constipation,” the authors concluded.

To download the full study, published in Gastroenterology, click here