Food groups associated with immune-mediated inflammatory diseases: a Mendelian randomization and disease severity...

Area of Science:

• Immunology
• Nutritional Science
• Epidemiology

Background:

• Immune-mediated inflammatory diseases (IMIDs) are common, yet the relationship between diet and IMIDs remains poorly understood.
• Key questions include how dietary patterns differ across IMIDs and if specific food groups exacerbate these conditions.

Purpose of the Study:

• To investigate dietary pattern alterations in six prevalent IMIDs compared to healthy controls.
• To determine if observed dietary changes are a cause or consequence of the disease using Mendelian randomization.
• To identify associations between specific food groups and disease severity within IMIDs.

Main Methods:

• Analysis of a nationwide cohort of 11,230 individuals (11,308 patients with IMIDs and 2,050 controls).
• Comparison of weekly food category intake between IMID patients and controls.
• Application of Mendelian randomization to infer causality of dietary changes.
• Statistical analysis of food frequency and disease severity within each IMID.

Main Results:

• All analyzed IMIDs exhibited significant dietary alterations, with at least three food categories significantly changed (P < 0.05).
• Inflammatory bowel diseases showed the most substantial dietary differences (≥8 categories, P < 0.05).
• Mendelian randomization confirmed disease-induced dietary changes, such as reduced vegetable intake in Crohn's Disease (P = 2.5 × 10⁻¹⁰).
• Except for Psoriatic Arthritis and Systemic Lupus Erythematosus, ≥2 food groups were significantly associated with increased disease severity (P < 0.05).

Conclusions:

• Prevalent IMIDs are linked to significant, disease-specific dietary pattern changes, some of which are caused by the disease itself.
• Specific food groups are associated with disease severity in most IMIDs studied.
• These findings emphasize the critical importance of considering diet in the context of IMIDs.