CATEGORY: GUT & DIGESTIVE HEALTH
Adults whose everyday eating most closely resembled a Mediterranean or plant-forward pattern were meaningfully less likely to develop chronic constipation than those whose diets least resembled them, an analysis of nearly 96,000 U.S. health professionals found. Because the study observed people’s habits rather than assigning diets, it shows an association, not proof that one causes the other.1
How the Study Worked
Researchers pooled three long-running studies — the Nurses’ Health Study, its sequel, and the Health Professionals Follow-Up Study — covering 95,917 adults, many in their 60s and 70s. Every four years participants completed detailed food questionnaires, which let the team score how closely each person’s usual eating matched five patterns. They then identified who developed chronic constipation, defined as symptoms lasting at least 12 weeks in a year, counting 7,519 new cases. Comparisons were adjusted for other influences, including how much fiber and ultra-processed food people ate.
What the Numbers Showed
Compared with those whose diets least resembled each pattern, people at the top for a Mediterranean-style diet had about 16% lower risk of chronic constipation, and those highest on a plant-based index about 20% lower. The reverse was also true: diets highest in inflammation-promoting or classic “Western” foods carried roughly 24% and 22% higher risk. Vegetables and nuts stood out as the foods most tied to lower risk.1
More Than Just Fiber
The protective link held even after accounting for fiber, hinting that these eating patterns help in other ways too. One likely route is the gut microbiome — the trillions of helpful bacteria living in your intestines. Plant-rich meals feed those bacteria, which produce short-chain fatty acids (helpful compounds that keep the intestinal lining healthy and stool moving) and may also calm inflammation throughout the body.
What This Does and Doesn’t Mean
Because this was observational, it can’t prove that changing how you eat would ease constipation, and the participants were mostly older health professionals, so results may not apply to everyone. Constipation can also have many causes. If it is persistent, painful, or new for you, that is worth raising with your doctor rather than self-treating.
Key Takeaways
- In a large study, eating patterns rich in vegetables, fruits, whole grains, legumes, nuts and healthy fats were linked to a lower risk of chronic constipation.
- The link held beyond fiber alone, pointing to the gut’s bacteria and lower inflammation as possible reasons.
- Persistent or troubling changes in bowel habits are worth discussing with your doctor, who can rule out other causes.
References
- Wang Y, Kuo B, Berschback M, Huttenhower C, Chan AT, Staller K. Dietary Patterns and Incident Chronic Constipation in Three Prospective Cohorts of Middle- and Older-Aged Adults. Gastroenterology. 2025;169(7):1475–1488. link