How we grade foods

Every grade on GoutSafe is built from published data, not opinion. Here is exactly how it works, and where the limits are.

Last reviewed June 13, 2026.

1. The data

Two things in food drive gout risk: purines, which break down into uric acid, and fructose, which raises uric acid production. For each food we store a value for both, per 100 grams, drawn from the USDA Purine Database, USDA FoodData Central, and peer-reviewed literature. We cover 514 foods today.

2. We score a typical serving

Raw lab values are reported per 100 grams, but you eat servings, not 100-gram blocks. So for each food we scale to a typical serving and work out how much purine that delivers, including as a share of a reasonable daily purine budget. This is why a food that looks alarming per 100 grams, like a dried fish or a spice, can still be fine in the amount you actually eat.

3. The A to E grade

We combine the per-serving purine and fructose load with known triggers and proven benefits into a single risk score, then map that score to a plain grade from A to E.

• Triggers push a grade toward higher risk: alcohol impairs uric-acid excretion, and added fructose raises uric acid, even when the raw purine number looks low. Because alcohol's risk comes from the ethanol itself and not its purine content, every alcoholic drink is graded at least D, and beer, which adds malt purines on top, is graded E. Non-alcoholic versions are graded on their content like any other drink.
• Benefits are noted when research links a food to lower uric acid or less inflammation, such as cherries or low-fat dairy. We show the supporting study on the food's page.

4. Confidence and what we don't know

Every food shows a confidence level, high, moderate, or limited, based on how well sourced its values are. A food reads high confidence only when both its purine and its fructose value are well sourced; if either is weaker or still pending, the food drops to moderate or limited. Where a number is measured on a concentrated form like skin-on fish or a dried ingredient, we flag it directly so it is not mistaken for an ordinary portion.

We also show where each number comes from. Every purine and fructose value carries its real source and a reliability tier on the food's page:

• Lab-verified (tier 1): direct laboratory measurement, such as the USDA Purine Database.
• Peer-reviewed literature (tier 2): published studies and international food tables.
• Estimated (tier 3): derived by composition rather than measured. For example, plain meat, seafood, and eggs contain no fructose, so we mark that value estimated instead of pretending it was tested in a lab.

That last flag matters: an honest "estimated" is more trustworthy than a number with no provenance at all. This is the difference between GoutSafe and the viral food advice that circulates without a single citation.

5. How we keep it honest

We do not publish "medically reviewed by" bylines, because we will not claim credentials we do not have. Instead we show our sources, our confidence, and our reasoning on every food, and we keep our claims conservative. If you spot an error, please tell us and we will correct it.