Short-Term Water-Only Fasting Raises Uric Acid While Improving Cholesterol and Weight: What the Research Shows

Short-Term Water-Only Fasting Raises Uric Acid While Improving Cholesterol and Weight: What the Research Shows

Medical disclaimer: This article summarises published research for informational purposes only. It is not medical advice and is not a substitute for guidance from a qualified health professional. Always consult your doctor before starting any fasting protocol, especially if you have an existing health condition or take medication.

Study at a Glance

What This Study Looked At

This trial grew out of earlier observational research from the same Utah-based research group, which had found that people who practiced routine, periodic 24-hour fasting had a lower long-term risk of coronary artery disease and diabetes. Those earlier studies couldn't prove cause and effect, so this randomized crossover trial was designed to test what short-term water-only fasting actually does to metabolic and cardiovascular markers under controlled conditions. You can read more about what happens to your body during a 24-hour fast and how intermittent fasting affects your kidneys for related context.

Who Was Studied

Participant profile: Adults with at least one cardiovascular risk factor, drawn from a population in which routine short-term fasting is a common cultural and religious practice. Exact age range and gender split were not independently verified for this article.

How the fasting protocol worked in this study: Participants completed 24-hour periods of water-only fasting — no food, only water — on a recurring basis during the fasting phase of the crossover design, with a separate control period of normal, unrestricted eating for comparison.

What the Researchers Found

Uric Acid

Uric acid rose during the water-only fasting periods. This is consistent with the known physiology of fasting: as the body shifts toward burning fat and producing ketone bodies, ketones compete with uric acid for the same excretion pathway in the kidneys, temporarily reducing how efficiently the kidneys clear uric acid from the blood.

Other Cardiometabolic Markers

• HDL cholesterol increased during the fasting phase, a favorable change for cardiovascular risk.
• Human growth hormone increased, consistent with other short-term fasting research.
• Body weight decreased during the fasting periods.

What Did Not Change

• The study's primary focus was on this cluster of cardiometabolic and hormonal markers; it was not designed to assess long-term joint health, gout flare frequency, or kidney stone formation, so no conclusions on those specific outcomes can be drawn from this trial.

What the Researchers Concluded

The researchers concluded that short-term water-only fasting produces a distinct metabolic signature — improving some cardiovascular risk markers like HDL cholesterol while transiently raising uric acid — supporting the idea that periodic fasting has measurable, direct physiological effects rather than simply reflecting long-term dietary habits in people who fast routinely.

What This Means If You Fast

• A temporary rise in uric acid during a fast is a normal, expected physiological response, not necessarily a sign something is wrong — it reflects ketones and fasting-related compounds competing with uric acid for renal clearance.
• If you have gout or a history of high uric acid, talk to your doctor before trying extended or frequent water-only fasts. A transient rise during a 24-hour fast is different from sustained hyperuricemia, but it's a legitimate reason for caution in people prone to gout flares.
• Staying well hydrated during a fast may help support uric acid clearance, since dehydration independently raises uric acid concentration.
• The cardiovascular benefits (higher HDL, weight loss) occurred in the same window as the uric acid increase — this is a tradeoff worth knowing about rather than a reason to avoid fasting altogether for most healthy people.
• Shorter or less frequent fasts may be a more cautious starting point if you're specifically concerned about uric acid or gout, compared to jumping straight into extended water-only fasting.

Study Limitations

• Sample size is modest (~30 participants), limiting how broadly the findings can be generalized.
• Population-specific. Participants were drawn from a population with a cultural tradition of routine fasting, which may not generalize to people fasting for the first time.
• Short-term design. The study captures acute changes during 24-hour fasts, not the long-term trajectory of uric acid with repeated fasting over months or years.
• No gout-specific outcomes measured. Flare frequency, joint symptoms, and kidney stone formation were not part of this study's design.
• This summary was written from model training knowledge because PubMed was inaccessible at the time of writing; exact participant counts, funding sources, and effect sizes could not be independently verified against the original abstract and should be treated as approximate.

Source

Horne BD, et al. (2013). Randomized cross-over trial of short-term water-only fasting: metabolic and cardiovascular consequences. Nutrition, Metabolism and Cardiovascular Diseases. Search on PubMed →

Frequently Asked Questions

Does intermittent fasting raise uric acid levels?

Short-term water-only fasting has been shown to transiently raise uric acid levels, largely because ketone bodies produced during fasting compete with uric acid for excretion by the kidneys. This appears to be a temporary physiological response rather than a sign of harm in otherwise healthy people.

Is intermittent fasting bad for people with gout?

People with gout or a history of high uric acid should be cautious with fasting, particularly longer or more frequent fasts, since fasting can temporarily raise uric acid. This doesn't mean fasting is off-limits, but it's a reason to talk to a doctor first and monitor how your body responds.

What other benefits did this study find from short-term fasting?

Alongside the uric acid increase, the study found improvements in HDL cholesterol, a rise in growth hormone, and reductions in body weight during the water-only fasting periods — findings broadly consistent with other short-term fasting research.

Why does fasting affect uric acid levels?

During fasting, the body increasingly relies on fat for fuel and produces ketone bodies. Ketones and uric acid share a renal transport pathway, so as ketone levels rise, the kidneys become less efficient at clearing uric acid, causing blood levels to rise temporarily.

Should I stay hydrated while fasting to protect against gout?

Yes — staying well hydrated during a fast supports kidney function and uric acid clearance. Dehydration independently raises uric acid concentration, so adequate water intake is a sensible precaution regardless of fasting protocol.

Related Research and Articles

• What happens to your body during a 24-hour fast?
• Intermittent fasting and kidney stones: what you need to know
• Fasting and kidney health: Bright's disease and modern kidney research
• What is alternate day fasting and does it work?
• Does intermittent fasting reduce inflammation?
• Intermittent fasting and inflammation: the research explained

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