Primary Data Sources
USDA+ODS-NIH PURINE DATABASE Release 2 (March 2025)
The most comprehensive English-language reference for food purine content. Developed jointly by the United States Department of Agriculture (USDA) and the National Institutes of Health Office of Dietary Supplements (ODS-NIH), this database covers all four purine bases (adenine, guanine, hypoxanthine, xanthine) plus total purines for hundreds of foods common in Western diets. Released in March 2025, it represents the most current and authoritative purine reference available.
Kaneko K, Aoyagi Y, Fukuuchi T, Inazawa K, Yamaoka N (2014)
This landmark study analyzed 270 foodstuffs using High-Performance Liquid Chromatography (HPLC) and categorized them into six purine risk classes. It is the most-cited purine reference in the gout medical literature and covers many foods common in Asian diets. The widely-referenced Japanese guideline of <400 mg/day dietary purine intake is derived from this work.
USDA SR28 Food Composition Tables
Fructose values on GoutFoodGuide are sourced from the USDA Standard Reference 28 (SR28) Food Composition Tables, the definitive reference for food nutrient composition in the United States.
How Purine Is Measured
The gold standard for purine analysis is High-Performance Liquid Chromatography (HPLC). The process involves:
- The food sample is hydrolyzed with acid (trifluoroacetic acid and formic acid) at 90°C for 12 minutes, breaking down purine-containing compounds into their four constituent bases.
- The resulting solution is filtered and injected into an HPLC column.
- The four purine bases (adenine, guanine, hypoxanthine, xanthine) are separated based on their chemical properties and detected at 254 nm wavelength.
- Concentrations are calculated by comparing peak areas against known standard solutions.
- Total purine content = sum of all four base concentrations.
Quality Tiers (T1/T2/T3)
| Tier | Description | Reliability |
|---|---|---|
| T1 | Both purine and fructose individually lab-measured by HPLC for that specific food item | Highest |
| T2 | One dimension lab-measured; the other estimated from scientific consensus for similar foods | Good |
| T3 | Category-level estimate — not individually measured | Directional only |
Risk Assessment Methodology
Our three-dimensional risk engine evaluates:
- Purine content — Safe: <50 mg/100g. Moderate: 50-150 mg/100g. Avoid: >150 mg/100g
- Fructose content — Safe: <2g/100g. Moderate: 2-5g/100g. Avoid: >5g/100g
- Alcohol — Any measurable alcohol content triggers AVOID rating
The final verdict is the most restrictive of the three dimensions. A food low in purines but high in fructose receives AVOID. This follows the ACR 2020 guideline principle that all three factors independently contribute to gout risk.