Uric acid builds up in your body when you produce more of it than you can get rid of, or when your kidneys and gut fall behind on clearing it out. Uric acid is the end product of breaking down purines, compounds found in your cells and in many foods. The balance between production and elimination is surprisingly delicate, and a wide range of factors can tip it: what you eat and drink, how well your kidneys work, your weight, your genetics, and even certain medications you might be taking for completely unrelated conditions.
Where Uric Acid Comes From
Every cell in your body contains purines, and your cells are constantly dying and being replaced. When a cell breaks down, its purines get metabolized into uric acid as a waste product. About two-thirds of the purines your body processes are endogenous, meaning they come from your own cells’ natural turnover. The remaining third comes from food, called exogenous purines, which get broken down during digestion.1PubMed Central. What Are Purines? The final step in that breakdown is handled by an enzyme called xanthine oxidase, which converts the intermediate products into uric acid.2PubMed Central. Role of Uric Acid Metabolism-Related Inflammation in the Pathogenesis of Metabolic Syndrome Components Such as Atherosclerosis and Nonalcoholic Steatohepatitis
This is worth pausing on, because many people assume uric acid problems are entirely about diet. In reality, your own body is manufacturing most of the purines in your system. You could eat an extremely low-purine diet and still have high uric acid if your cells are turning over rapidly or if your body is poor at eliminating it.
How Your Body Gets Rid of Uric Acid
Your kidneys do most of the heavy lifting, handling roughly two-thirds of uric acid elimination. The process is more complex than simple filtration: uric acid gets filtered, then largely reabsorbed back into the blood, then partly secreted again into the urine. The net result is that only a fraction of the filtered uric acid actually leaves your body. Two key transporter proteins in the kidney, known as URAT1 and GLUT9, are the main players pulling uric acid back from the urine into the bloodstream.3PubMed Central. SGLT2 inhibition and renal urate excretion: role of luminal glucose, GLUT9, and URAT1 GLUT9 appears to contribute more to reabsorption than URAT1, and together they act as a finely tuned dial controlling how much uric acid stays in your blood versus how much leaves through urine.4PubMed Central. Glut9 is a major regulator of urate homeostasis and its genetic inactivation induces hyperuricosuria and urate nephropathy
The remaining third of uric acid elimination happens through the intestines, a route that only became well understood in the last couple of decades. A transporter protein called BCRP (also known as ABCG2) actively pumps uric acid from the bloodstream into the intestinal lumen, where gut bacteria break it down further. When researchers knocked out the gene for this transporter in mice, blood uric acid levels shot up and intestinal excretion dropped by more than half.5PubMed. ABCG2 dysfunction increases serum uric acid by decreased intestinal urate excretion This intestinal pathway is a genuinely important safety valve: if your kidneys are struggling, the gut can pick up some slack, but only if this transporter is functioning well.6PLOS ONE. Extra-Renal Elimination of Uric Acid via Intestinal Efflux Transporter BCRP/ABCG2
Diet and Uric Acid
Certain foods reliably raise uric acid levels, but the pattern is not as simple as “avoid all purines.” The strongest dietary links are with meat and seafood. A large prospective study following tens of thousands of men found that those who ate the most meat had about a 41% higher risk of developing gout compared to those who ate the least. Seafood showed an even slightly stronger effect, with a 51% higher risk in the highest-intake group.7PubMed. Purine-rich foods, dairy and protein intake, and the risk of gout in men Data from the U.S. National Health and Nutrition Examination Survey confirmed that uric acid levels climbed with increasing meat and seafood consumption.8PubMed. Intake of purine-rich foods, protein, and dairy products and relationship to serum levels of uric acid: the Third National Health and Nutrition Examination Survey
Here is where things get counterintuitive: purine-rich vegetables like mushrooms, spinach, and asparagus were not associated with higher uric acid levels or gout risk in those same studies. Neither was total protein intake. And dairy products actually appeared protective, with the highest dairy intake linked to a 44% lower risk of gout compared to the lowest.7PubMed. Purine-rich foods, dairy and protein intake, and the risk of gout in men Similarly, a study of Chinese men found that soy food consumption trended toward lower uric acid levels, not higher, despite soy being a purine-containing food.9PubMed Central. Purine-rich foods, protein intake, and the prevalence of hyperuricemia: the Shanghai Men’s Health Study The upshot is that the type of purine and its food context matter far more than the total purine count on a nutrition label.
Fructose
Fructose stands apart from other dietary triggers because it raises uric acid through a completely different mechanism than purine-rich foods. When your liver metabolizes fructose, it rapidly burns through a molecule called ATP, and the breakdown products of ATP are purines. So fructose does not deliver purines to your body; it forces your body to generate them internally. This mechanism has drawn increasing attention as a link between sugary diets and metabolic problems like insulin resistance and fatty liver disease.10PubMed Central. Fructose and Uric Acid: Major Mediators of Cardiovascular Disease Risk Starting at Pediatric Age Table sugar is half fructose, and high-fructose corn syrup is the dominant sweetener in soft drinks in many countries, making this a significant contributor to population-level uric acid levels.
Alcohol
Alcohol raises uric acid levels through multiple pathways at once. Ethanol speeds up the breakdown of adenine nucleotides (a type of purine) and simultaneously raises lactic acid in the blood, which competes with uric acid for excretion through the kidneys. Beer adds a double hit because it also contains significant purines of its own. Dehydration from heavy drinking can further concentrate uric acid in the blood.11PubMed. Effect of ethanol on metabolism of purine bases (hypoxanthine, xanthine, and uric acid) Of all alcoholic drinks, beer is consistently the worst offender for gout risk, with spirits in second place and wine showing a much weaker association in most studies.
Insulin Resistance and Obesity
The connection between metabolic health and uric acid is one of the most important and least appreciated pieces of this puzzle. Insulin resistance, the condition where your cells stop responding well to insulin, directly reduces how much uric acid your kidneys excrete. In a study of healthy volunteers, the more insulin-resistant a person was, the lower their kidney clearance of uric acid, and the higher their blood levels.12JAMA. Relationship Between Resistance to Insulin-Mediated Glucose Uptake, Urinary Uric Acid Clearance, and Plasma Uric Acid Concentration The mechanism works through the same kidney transporters discussed earlier: insulin increases the activity of URAT1, which reabsorbs uric acid back into the blood, while simultaneously decreasing ABCG2, which would otherwise help clear it through the gut.13PubMed. Insulin stimulates uric acid reabsorption via regulating urate transporter 1 and ATP-binding cassette subfamily G member 2
Obesity adds another layer. Fat tissue does not just store energy passively; it actively produces uric acid. Research using mouse models found that fat tissue is one of the major organs expressing xanthine oxidase, the enzyme that catalyzes the final step of uric acid production. In obese mice, fat tissue had higher enzyme activity and secreted more uric acid than in lean animals, and administering a xanthine oxidase inhibitor brought plasma uric acid back down.14PubMed Central. Uric acid secretion from adipose tissue and its increase in obesity Visceral fat, the deep belly fat around your organs, has a particularly strong positive correlation with uric acid levels, with the risk of elevated uric acid climbing steeply as visceral fat increased through quartiles.15PubMed. Association between visceral fat area and serum uric acid in Chinese adults: A cross-sectional study
This creates a vicious feedback loop. Excess body fat produces more uric acid. Insulin resistance, which often accompanies obesity, makes the kidneys hold onto more of it. High uric acid itself may worsen insulin resistance and fatty liver. For people trying to bring down uric acid levels, losing weight can sometimes accomplish more than any dietary adjustment to specific foods.
Medications That Push Uric Acid Up
Several widely prescribed medications raise uric acid as a side effect that catches people off guard.
- Diuretics: Thiazide and loop diuretics, commonly prescribed for high blood pressure and heart failure, are among the most frequent medication-related causes of elevated uric acid. Thiazides like hydrochlorothiazide enhance the activity of a kidney transporter called OAT4, which pulls uric acid back into the blood from the kidney tubules.16Journal of Clinical Images and Medical Case Reports. Effect of diuretic medication and coffee consumption on serum uric acid levels: A review of literature The dehydration that diuretics cause only compounds the problem.
- Low-dose aspirin: The daily baby aspirin that millions of people take for cardiovascular protection has been linked to decreased uric acid excretion. A case report described a patient whose gout remained uncontrolled despite strict lifestyle practices and medication compliance, and the condition only improved once aspirin was identified and addressed as a contributing factor.17Cureus. Identifying Aspirin as a Contributing Factor to Persistent Gout: A Case Report
- Immunosuppressants: Cyclosporine, used after organ transplants and for certain autoimmune conditions, reduces kidney excretion of uric acid and is a well-recognized cause of post-transplant gout.
If you have been diagnosed with elevated uric acid or gout and are taking any of these medications, it is worth asking your doctor whether alternatives exist. Sometimes the medication change alone can bring levels down.
Genetics and the Uric Acid Lottery
Your genes have a large influence on where your uric acid levels land. Genome-wide studies have repeatedly identified the gene SLC2A9, which encodes the GLUT9 transporter, as having one of the strongest associations with both uric acid levels and gout risk across diverse populations.18Human Molecular Genetics. Genetic variants associated with gout identified through a genome-wide study in the UK biobank Variants in SLC2A9 have been linked to gout in European, Chinese, and Polynesian populations.19PubMed Central. The genetics of hyperuricaemia and gout The gene encoding URAT1, another key kidney transporter, has also shown significant linkage with uric acid variation in studies of American Indian families.20PubMed Central. Genetic influence on variation in serum uric acid in American Indians: the strong heart family study
Similarly, variants in the ABCG2 gene, responsible for the intestinal excretion pathway, can substantially reduce how much uric acid your gut eliminates. People carrying common loss-of-function variants in this gene are at meaningfully higher risk of gout because their backup excretion route is compromised.5PubMed. ABCG2 dysfunction increases serum uric acid by decreased intestinal urate excretion This is a particularly important finding because it helps explain why some people develop gout despite having normal-looking kidney function: their intestinal pathway is underperforming without anyone realizing it.
At the extreme end, rare genetic disorders can cause dramatic uric acid overproduction. Deficiency of the enzyme HPRT leads to a spectrum of conditions, the most severe being Lesch-Nyhan syndrome, which causes massive uric acid overproduction along with neurological problems. Even partial HPRT deficiency can produce severe gout and kidney stones starting in childhood or early adulthood.21PubMed Central. Update on the phenotypic spectrum of Lesch-Nyhan disease and its attenuated variants22PubMed Central. Hypoxanthine-guanine phosophoribosyltransferase (HPRT) deficiency: Lesch-Nyhan syndrome
Why Humans Are Especially Vulnerable
There is a deeper evolutionary story behind human susceptibility to uric acid buildup. Most mammals have an enzyme called uricase that breaks uric acid down further into a much more soluble compound called allantoin, which washes out easily through the kidneys. Humans and other apes lost this enzyme millions of years ago through multiple independent mutations that silenced the uricase gene.23PubMed Central. Evolutionary history and metabolic insights of ancient mammalian uricases The result is that blood uric acid concentrations in humans are more than ten times higher than in most other mammals.24Molecular Biology and Evolution. Loss of Urate Oxidase Activity in Hominoids and its Evolutionary Implications
Why evolution let this happen is still debated. Uric acid is a potent antioxidant in the blood, and one hypothesis is that losing uricase provided a survival advantage by boosting antioxidant defenses. Another theory links it to blood pressure maintenance in early hominids who had low-sodium diets and needed higher blood pressure to stay upright. Whatever the reason, the trade-off is that humans live much closer to the threshold of uric acid crystallization than other animals, which is why gout is essentially a human and great-ape disease.
Hormones and the Sex Gap
Men develop gout far more often than premenopausal women, and estrogen appears to be a major reason. Estrogen promotes uric acid excretion through the intestinal ABCG2 transporter. In a study comparing patients with gout or elevated uric acid to healthy controls, the patients had significantly lower estrogen levels and significantly higher uric acid levels.25PubMed Central. Estradiol regulates intestinal ABCG2 to promote urate excretion via the PI3K/Akt pathway This helps explain why women’s gout risk rises sharply after menopause, when estrogen levels decline. It also helps explain why men, who have lower estrogen levels throughout life, tend to accumulate uric acid more readily.
Testosterone may also play a role. Some research suggests that testosterone reduces kidney uric acid excretion, though the evidence is less developed than for estrogen’s protective effect. The practical takeaway is that biological sex and hormonal status are strong background factors that influence where your uric acid level naturally sits, independent of diet or lifestyle.
Rapid Cell Turnover and Tumor Lysis
Any condition that dramatically accelerates cell destruction can flood the body with purines and spike uric acid levels. The most dramatic example is tumor lysis syndrome, which occurs when cancer treatment destroys a large number of malignant cells simultaneously. The dying cells release their intracellular contents, including purines, into the bloodstream all at once. The resulting surge in uric acid can overwhelm the kidneys and lead to acute kidney injury.26PubMed Central. The tumor lysis syndrome This is why oncologists routinely give preventive medications before starting chemotherapy for fast-growing cancers.
Less dramatically, conditions involving high cell turnover like psoriasis, hemolytic anemias (where red blood cells are destroyed faster than normal), and myeloproliferative disorders can chronically elevate uric acid levels. Even intense exercise causes temporary spikes because of accelerated muscle cell turnover and ATP breakdown.
Kidney Disease as Both Cause and Consequence
Since the kidneys are responsible for most uric acid elimination, any decline in kidney function can impair clearance and lead to buildup. Hyperuricemia is present in roughly 60% of people with chronic kidney disease.27PubMed Central. Uric Acid and Chronic Kidney Disease: Still More to Do The relationship is bidirectional: kidney disease raises uric acid, and chronically high uric acid may itself contribute to further kidney damage through crystal deposition and inflammation. This creates a feedback loop that can be difficult to interrupt, which is why nephrologists often monitor uric acid levels as part of routine kidney disease management.
Ketogenic Diets and Short-Term Spikes
People starting a very-low-carbohydrate or ketogenic diet sometimes experience a temporary jump in uric acid levels. The likely explanation is that ketone bodies, which rise steeply when carbohydrate intake drops, compete with uric acid for the same organic acid transporters in the kidneys. When those transporters are busy clearing ketones, less uric acid gets excreted.28Kidney Res Clin Pract. The case for a ketogenic diet in the management of kidney disease – Section: Kidney stones For most people, this resolves after a few weeks as the body adapts, but it occasionally triggers a gout flare in people who are already near the threshold. If you have a history of gout and are considering a ketogenic diet, a gradual transition is safer than an abrupt switch, and keeping well hydrated helps the kidneys compensate.