Do Nuts and Seeds Cause Diverticulitis?
No, nuts and seeds do not cause diverticulitis and should not be restricted from the diet. In fact, evidence suggests they may actually be protective against diverticular complications.
The Evidence Against Dietary Restrictions
The 2021 American Gastroenterological Association (AGA) guidelines explicitly state that nut, corn, and popcorn consumption is not associated with an increased risk of diverticulitis 1. Similarly, consuming fruits with small seeds (strawberries and blueberries) is not associated with diverticulitis risk 1.
This recommendation is supported by high-quality prospective research:
- A landmark 18-year prospective study of 47,228 men found inverse associations between nut and popcorn consumption and diverticulitis risk 2
- Men consuming nuts at least twice per week had a 20% lower risk of diverticulitis compared to those eating nuts less than once monthly (HR 0.80,95% CI 0.63-1.01) 2
- Popcorn consumption showed even stronger protection, with a 28% risk reduction (HR 0.72,95% CI 0.56-0.92) 2
- A 2025 systematic review of over two million person-years demonstrated that moderate nut intake is safe and may be protective, with a 5% linear risk reduction per additional weekly serving 3
Why This Myth Persists
The outdated recommendation to avoid nuts, seeds, corn, and popcorn was based on the theoretical concern that these foods could enter, block, or irritate a diverticulum 4. This theory has never been supported by evidence 4.
What Actually Reduces Diverticulitis Risk
Instead of restricting nuts and seeds, the AGA recommends patients focus on evidence-based prevention strategies 1, 5:
- Consume a high-quality diet rich in fiber from fruits, vegetables, whole grains, and legumes (>22.1 g/day), while keeping red meat and sweets low 1, 6
- Maintain regular vigorous physical activity, which decreases diverticulitis risk 1, 7
- Achieve or maintain normal body mass index (18-25 kg/m²), as obesity increases risk 1, 7
- Avoid smoking, which is an established risk factor 1, 7
- Limit non-aspirin NSAIDs when possible, as they increase diverticulitis risk 1, 7
Critical Clinical Pitfall to Avoid
Do not unnecessarily restrict nuts, seeds, popcorn, or small-seeded fruits 5, 7. This outdated advice is not evidence-based and may actually reduce beneficial fiber intake, potentially increasing diverticulitis risk 5, 7. Fiber supplements can complement but should never replace a high-quality whole food diet that includes nuts and seeds 1, 6.
Important Context
Approximately 50% of diverticulitis risk is attributable to genetic factors that cannot be modified through diet 1, 7. While dietary modifications are beneficial, patients should understand that lifestyle changes reduce but do not eliminate recurrence risk 6.