What are the guidelines and efficacy of an anti-inflammatory diet?

Anti-Inflammatory Diet Guidelines and Efficacy

There is no single "anti-inflammatory diet" that can be generally recommended to promote remission in patients with inflammatory bowel disease (IBD) or other inflammatory conditions, though diets rich in fruits, vegetables, n-3 fatty acids, and low in n-6 fatty acids are associated with decreased risk of developing inflammatory conditions. 1

Evidence-Based Dietary Patterns for Reducing Inflammation

Recommended Components of Anti-Inflammatory Diets

• A diet rich in fruits and vegetables is associated with decreased risk of developing Crohn's Disease (CD) and Ulcerative Colitis (UC), with higher intake of dietary fiber (>22 g/day) specifically linked to reduced CD risk 1
• Consumption of vegetables is negatively associated with risk of UC (OR = 0.71) 1
• Higher consumption of fruit is negatively associated with both UC (OR = 0.69) and CD (OR = 0.57) 1
• A Mediterranean-style diet rich in fruits, vegetables, complex carbohydrates, and monounsaturated fats is recommended for many patients with inflammatory conditions 1
• Plant-based nutrients are associated with reduction in systemic inflammation 2
• Higher intakes of fruit and vegetables lead to both reduction in pro-inflammatory mediators and enhanced immune cell profile 3

Components to Limit or Avoid

• High intake of PUFAs, n-6 fatty acids, and meats is associated with increased risk of developing UC and CD 1
• Red meat and excessive dairy consumption may increase systemic inflammation and risk of inflammatory flares 2
• Ultraprocessed foods and low intake of dietary fiber have been associated with increased risk of developing CD 1
• High long-term intake of trans-unsaturated fatty acids is associated with increased incidence of UC (HR 1.34) 1

Efficacy of Anti-Inflammatory Diets

Clinical Evidence

• Meta-analysis shows fruit and vegetable intake decreased circulating levels of C-reactive protein and tumor necrosis factor-α (P < 0.05) 3
• Plant-based diets may contribute to lower risk of cardiovascular diseases and cancer through anti-inflammatory activities 4
• Majority of intervention studies (68%) reported beneficial effects of fruit or vegetable intake on at least one biomarker of systemic or airway inflammation 3

Special Considerations for IBD

• For Crohn's Disease with mild to moderate activity, the Crohn's Disease Exclusion Diet (CDED) plus partial enteral nutrition (EN) should be considered in pediatric patients 1
• In adult patients with mild to moderate active CD, CDED can be considered with or without EN 1
• For patients with intestinal strictures or stenosis with obstructive symptoms, a diet with adapted texture or exclusive EN via a tube ending distal to the obstruction can be recommended 1

Mechanisms of Action

• Anti-inflammatory diets may work through multiple pathways:
  • Modulating the gut microbiome 1
  • Providing bioactive compounds that inhibit inflammatory pathways 4
  • Increasing short chain fatty acid production 1
  • Silencing genes involved in the generation of silent inflammation 5
  • Stabilizing insulin and reducing intake of omega-6 fatty acids 5

Common Pitfalls and Caveats

• Despite patient interest in dietary modifications, high-quality dietary intervention studies are still needed to facilitate creation of evidence-based dietary guidelines 1
• Patient-targeted dietary recommendations from internet sources are often conflicting and may lack scientific evidence 1
• Long-term adherence to restrictive diets may be challenging and could potentially lead to nutritional deficiencies 1
• The practicality of maintaining interventions like specific carbohydrate diet, FODMAP, or Paleo diet over long periods is doubtful 1
• Adherence to defined diets may result in unnecessary financial burden or reduction in overall caloric intake in patients already at risk for protein-calorie malnutrition 1

Practical Approach

• Focus on a Mediterranean-style diet rich in fruits, vegetables, complex carbohydrates, and monounsaturated fats 1
• Aim for at least 22g of fiber daily from fruits and vegetables 1
• Increase consumption of foods with omega-3 fatty acids while reducing omega-6 fatty acids 1
• Consider supplemental omega-3 fatty acids at 2-3g of EPA and DHA per day 5
• For patients with IBD, keeping a food diary to identify individual triggers may be helpful 1
• Modify texture of fibrous foods by cooking, blending, and thoroughly chewing fruits and vegetables for patients with stricturing IBD 1