Can the Carnivore Diet Affect Calprotectin Levels?
Yes, a carnivore diet (high in meat and animal protein) can elevate calprotectin levels even in the absence of inflammatory bowel disease, based on dietary intervention studies showing that higher protein and meat intake correlate with increased calprotectin. 1, 2
Evidence for Dietary Effects on Calprotectin
Protein and Meat Intake
A prospective dietary intervention study demonstrated that calprotectin in serum tended to increase after 12 weeks of a diet with higher protein content, with energy percentage of protein in meals directly correlating with serum calprotectin levels (P=0.008). 1
In a cross-sectional study of 103 IBD patients, those in the highest quartile for meat consumption had a 3.61-fold higher risk of active disease (as measured by elevated fecal calprotectin), though this association was attenuated after adjustment. 2
The same study found an inverse relationship between legume/potato consumption and disease activity, with the highest quartile of legume intake associated with 79% lower risk of elevated calprotectin (adjusted OR 0.21,95% CI 0.57-0.81). 2
Mechanism and Clinical Implications
Calprotectin is a 36kDa protein derived predominantly from neutrophils that serves as a marker of intestinal inflammation, with fecal concentrations approximately six times higher than plasma levels. 3
The carnivore diet's extremely high meat content and complete absence of plant foods (legumes, vegetables, fiber) creates a dietary pattern opposite to what correlates with lower calprotectin levels in intervention studies. 2
Important Caveats for Interpretation
When Elevated Calprotectin Matters Clinically
NSAID use in the past 6 weeks can significantly elevate calprotectin levels and must be excluded before attributing elevation to diet alone. 4, 5
Calprotectin >150 μg/g has 78.2% specificity for endoscopically active disease, meaning 22% of elevations may be false positives in asymptomatic individuals. 6, 4
Values between 50-250 μg/g represent an indeterminate range with only 8% risk of developing IBD over 12 months compared to 1% with levels <50 μg/g. 4
Other Non-IBD Causes to Consider
Hemorrhoids can cause false elevations due to local bleeding and inflammation, particularly if visible rectal bleeding is present. 4, 5
Colorectal neoplasia must be excluded in patients over 50 or with alarm symptoms like rectal bleeding, as this is a well-established cause of elevated calprotectin. 4
The first stool passed in the morning should be used for sampling and analyzed within 3 days at room temperature to avoid falsely elevated results from sample degradation. 6, 7, 5
Clinical Approach to Elevated Calprotectin on Carnivore Diet
If Asymptomatic with Mild Elevation (50-250 μg/g)
Consider repeating calprotectin in 4-6 weeks, as there is substantial within-patient variability ranging from 13-114% using the same assay on different samples from the same individual. 6
Review all medications, particularly NSAIDs taken in the past 6 weeks, and discontinue if possible before repeat testing. 4
If Symptomatic or Persistently Elevated >250 μg/g
Proceed to colonoscopy with biopsies to evaluate for IBD, microscopic colitis, and colorectal neoplasia, as values >250 μg/g have 82% specificity for active inflammatory disease. 6, 4
Ensure celiac serology (tissue transglutaminase antibodies) has been checked, as untreated celiac disease causes intestinal inflammation that elevates calprotectin. 4