Caution: Urine Stones and Gout Attacks – Purine Traps at Christmas

Uric acid urinary stones and gout attacks have one thing in common: they are caused by elevated uric acid levels due to increased purine intake. Purines such as adenine and guanine are building blocks of genetic material—DNA and RNA—and are found in many foods. Protein-rich products, such as various types of meat, are particularly high in purines. When purines are metabolized, uric acid is produced as the end product and excreted in the urine.

When too much uric acid becomes a problem

If a particularly large amount of uric acid is produced, it may settle in joints and cause an inflammatory reaction there. This is called a gout attack. In addition, uric acid crystals can accumulate in excessive amounts in the urine and lead to the formation of urine stones. In Germany, uric acid stones account for around ten percent of all urinary stones; men are affected significantly more often than women. The overall prevalence of kidney stone disease in Germany is around five percent—on a scale comparable to diabetes or rheumatism.

The purine traps at Christmas

In addition to the typically meat-heavy diet at Christmas, the often increased alcohol consumption also promotes the formation of uric acid stones and gout attacks. Beer contains particularly high levels of purines due to yeast—regardless of whether it is alcoholic or non-alcoholic beer. In addition, alcohol raises uric acid levels regardless of purine content: alcohol breakdown produces lactate, which competes with uric acid in the kidneys for excretion. As a result, less uric acid is excreted and more is reabsorbed. Alcohol consumption also creates an acidic urine environment and dehydrates the body, which is associated with higher urine concentrations. All of these factors promote the formation of urinary stones.

A typical Christmas meal consisting of roast, sauce, dumplings, and red cabbage, along with a glass of wine or beer, can—depending on portion size and preparation—already contain more purines than recommended for an entire day. A guideline value is around 400 to 500 milligrams of uric acid equivalent per day. Meat in particular, organ meats such as liver, and especially beer are considered classic purine traps.

What current guidelines recommend

For a long time, a strict low-purine diet was considered the gold standard for gout. The new S3 guideline of the German Society for Rheumatology (as of January 2025) now takes a different approach: instead of rigorously banning individual foods, the focus is now on a plant-forward diet with plenty of fruit and vegetables, reducing alcohol—especially beer—and maintaining a healthy body weight. Adequate fluid intake of about two to two and a half liters per day is also important, ideally bicarbonate-rich mineral water, which slightly alkalizes the urine and improves the solubility of uric acid. The method of preparation also plays a role: when boiling, up to twenty percent of purines transfer into the cooking water, whereas with frying/roasting, hardly any do.

When You Should Not Hesitate

Medical help should be sought promptly, especially if a gout attack is accompanied by fever or chills—this may indicate bacterial joint inflammation. Immediate evaluation is also required in cases of severe flank pain that may radiate to the groin or lower abdomen, blood in the urine, or high fever, as acute renal colic with infection can constitute a urological emergency.

Sources

AWMF – S3 Guideline “Diagnosis and Treatment of Gout” (DGRh, 060-005, January 2025): register.awmf.org
AWMF – S2k Guideline “Urolithiasis” (DGU, 043-025): register.awmf.org
European Association of Urology (EAU) – Guidelines on Urolithiasis: uroweb.org
German Nutrition Society (DGE) – Information on purines and uric acid: dge.de
Deutsches Ärzteblatt – Alcohol consumption and gout risk: aerzteblatt.de