Table 1.

Risk Factors for Incident Diverticulitis

Risk Factor	Category	RR/ORa	References
Diet
Fiber	Highest quintile	0.57–0.75	48, 49
Nuts	> 2 times/week	0.80	50
Popcorn	> 2 times/week	0.72	50
Vegetarian diet	Yes/no	0.69	49
Prudent dietary patternb	Highest quintile	0.74	39
Western dietary patternc	Highest quintile	1.55	39
Red meat	Highest quintile	1.58	38
Lifestyle
Physical activity	Highest quintile	0.63–0.75	40, 51, 52
Body mass index (BMI)	BMI ≥ 30	1.33–4.4	40–42
Waist-to-hip ratio	Highest quintile	1.62	42
Smoking	Current or ≥ 15 cigarettes/day	1.23–1.89	41, 45, 46
Medications
Non-aspirin NSAIDs	≥ 2 times/week	1.72	58
Aspirin	Ever or ≥ 2 times/week	1.25–1.32	57, 58
All NSAIDs	≥ 2 times/week	1.62	58
Corticosteroids	Current use	2.74	57
Opiate analgesics	Current use	2.16	57
Statins	Current use	0.44	57
Vitamin D	Highest quintile	0.49	61
Sibling with diverticular disease	Yes/no	2.92	97

^aEffect estimates are from select, large, population-based cohort or case-controls studies with adjustment for confounding variables. The study outcomes include hospitalization for diverticulitis, symptomatic diverticular disease and diverticulitis managed in the inpatient or outpatient setting depending on the study.

^bPrudent dietary pattern is high in fruits, vegetables and whole grains

^cWestern dietary pattern is high in red meat, high-fat dairy, and refined grains