🎯 Clinical Bottom Line

This large prospective cohort study provides compelling evidence to refute the historical dogma that women should avoid “particulate” foods—specifically nuts, seeds, corn, and popcorn—to prevent diverticulitis. In fact, the data indicates that high intake of corn may even be protective. Furthermore, the study demonstrates that adherence to high-quality dietary patterns (such as the DASH or Healthy Eating Index) is associated with a significant reduction in the risk of incident diverticulitis. For the general clinician, this supports advising patients to consume a broad, high-fiber diet including nuts and seeds, rather than restricting them.

---

 

📈 Results in Context

Main Results (Nuts, Seeds, and Corn)

The study found no evidence that consuming these foods increases risk.

• Peanuts, Nuts, and Seeds: Comparing the highest quartile of intake to the lowest, there was no significant association with incident diverticulitis (Adjusted Hazard Ratio [aHR]: 1.07; 95% CI: 0.91–1.25).

• Corn: Surprisingly, higher corn intake was associated with a reduced risk of diverticulitis (aHR: 0.86; 95% CI: 0.74–0.99).

• Fruits with Edible Seeds: Intake of strawberries and raw tomatoes was not associated with increased risk (aHR: 1.06; 95% CI: 0.90–1.24).

 

Main Results (Dietary Patterns)

 

High-quality diets were generally protective when comparing the highest quartile of adherence to the lowest:

• DASH Diet: 23% risk reduction (aHR: 0.77; 95% CI: 0.65–0.90).

• Healthy Eating Index (HEI) 2015: 22% risk reduction (aHR: 0.78; 95% CI: 0.66–0.91).

• Alternative Mediterranean Diet: The association suggested a benefit but the confidence interval crossed the null (aHR: 0.91; 95% CI: 0.78–1.06).

 

Definitions

 

• Adjusted Hazard Ratio (aHR): An estimate of the relative risk of the event occurring in the exposed group compared to the unexposed group, accounting for confounding variables. An aHR < 1.0 suggests the exposure is protective.

 

Participants

 

• The analysis included 29,916 women who contributed 415,103 person-years of follow-up.

• 1,531 incident cases of diverticulitis were identified.

---

 

🧐 Assertive Critical Appraisal

 

 

Limitations & Bias (STROBE Framework)

 

• Selection and Survivor Bias: The study design required participants to survive and remain enrolled until the 5th follow-up questionnaire (2020-2022) to report their history of diverticulitis. This introduces “immortal time” bias and potential selection bias. While the authors utilized inverse probability of selection weights to mitigate this, it remains a structural limitation compared to real-time incident tracking.

• Measurement Error (Outcome): Diagnoses were self-reported. A validation sub-study showed that only 73% of self-reported diverticulitis/diverticulosis cases were confirmed by medical records. This suggests a moderate degree of outcome misclassification, which typically biases results toward the null (finding no effect).

• Measurement Error (Exposure): Diet was assessed only at enrollment. Dietary habits can change significantly over the mean 13.9-year follow-up period. However, the authors argue that assessing diet years prior to diagnosis reduces reverse causality (where a patient changes their diet because of early symptoms).

 

Reporting Quality Assessment (STROBE)

 

• Confounding: The reporting on confounding is robust. The authors adjusted for a comprehensive list of covariates, including BMI, physical activity, NSAID use, and smoking.

• Missing Data: The authors appropriately handled missing covariate data using multiple imputation, a standard statistical technique to reduce bias.

 

Applicability

 

• Population: The “Sister Study” cohort consists of sisters of women with breast cancer. While they are a large group, they are predominantly Non-Hispanic White (88.6%) and may have different health-seeking behaviors than the general population. However, biological mechanisms regarding diet and diverticula are unlikely to differ by race or family history of breast cancer.

---

 

🔬 Research Objective

 

The objective was to determine whether dietary intake of nuts, seeds, and corn is associated with increased diverticulitis risk in women, and to evaluate if healthy dietary patterns are associated with reduced risk.

---

 

📝 Study Design

 

• Design: Prospective cohort study.

• Data Source: The Sister Study (National Institute of Environmental Health Sciences).

 

Setting and Participants

 

• Setting: United States and Puerto Rico.

• Inclusion: Women aged 35-74 at enrollment with no history of inflammatory bowel disease, cancer, or diverticulitis.

• Timeline: Enrollment occurred between 2003–2009; diverticulitis history was assessed in 2020–2022.

---

 

📚 Bibliographic Data

 

• Title: Diet and Risk for Incident Diverticulitis in Women – A Prospective Cohort Study

• Authors: Barlowe T, Anderson C, Nichols HB, Salvador AC, Sandler RS, Sandler DP, Peery AF

• Journal: Annals of Internal Medicine

• Year: 2025

• DOI: 10.7326/ANNALS-24-03353

---

This AI-generated analysis is for informational and research purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition.