Study finds Mediterranean or plant-based diets may help reduce risk of chronic constipation in middle- and older-age adults

The incidence of chronic constipation increases as we age. A new study from Mass General Brigham researchers compares five common diets to determine the effectiveness of preventing chronic constipation in middle- and older-age adults. The team studied over 96,000 adults for several years to understand how different eating habits affect the risk of developing the chronic gastrointestinal condition. They found people who followed a Mediterranean or plant-based diet were less likely to develop constipation. Their results are published in Gastroenterology.

“Chronic constipation affects millions of people and can significantly impact a patient’s quality of life,” said senior author Kyle Staller, MD, MPH, of the Division of Gastroenterology at Massachusetts General Hospital, a founding member of the Mass General Brigham healthcare system. “Our findings suggest that as we age, certain healthy diets may provide benefits to our gut beyond the known cardiovascular benefits.”

It’s been established that healthy diets can improve constipation symptoms, but this is the first study to show that certain diets can prevent people from developing chronic constipation. “We have always assumed that the benefits of eating a healthy diet would be driven by fiber, but our analyses showed the benefit of these healthy diets on constipation were independent of fiber intake,” said Staller.

Using data from the Nurses’ Health Study, Nurses’ Health Study II and the Health Professionals Follow-Up Study, the researchers tracked dietary patterns in middle- and older-age adults and examined who developed chronic constipation, which was defined as having symptoms for at least 12 weeks in a year. Diets included in the analysis were the Mediterranean diet, plant-based diet, low-carb diet, Western diet and inflammatory diet. Individuals who adhered to a Western or inflammatory diet were more likely to develop chronic constipation. In addition, participants who ate a low-carb diet didn’t show a strong effect.

“Our findings suggest a diet rich in vegetables, nuts and healthy fats may help prevent chronic constipation in middle- and older-age adults,” said Staller.

Reference:

Wang, Yiqing et al., Dietary Patterns and Incident Chronic Constipation in Three Prospective Cohorts of Middle- and Older-aged Adults, Gastroenterology, DOI: 10.1053/j.gastro.2025.06.020.