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By Dr. Andreas Eenfeldt, MD
, medical review by Dr. Bret Scher, MD
– Updated September 18, 2020 Evidence based
Do low-carb or keto diets high in meat cause gout? We are not aware of any evidence proving this, and this guide will explore why, or why not, this may be true.
First of all, a low-carb diet is not necessarily high in meat, and even those that are high in meat are markedly different from the standard American diet high in meat.
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Instead, since all low-carb diets are low in sugars and refined carbohydrates, there is a potential for them to reduce the risk of gout rather than increase it.
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Keep reading to find out what gout is, how to avoid it, and how a low-carb diet may affect it.
Gout is a sudden and painful inflammation of a joint, most often at the base of the big toe (see image). It may also affect other joints, like heels, knees, wrists and finger joints.
The cause of gout is elevated levels of uric acid in the blood, resulting in crystals depositing in the affected joint.
Gout is more common in people who are overweight and have metabolic syndrome, and have thus become more common in recent decades, affecting about 6% of adult men and 2% of women (it’s even more common in older people).
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Historically, it was known as “the disease of kings” or a “rich man’s disease”, but now everyone can afford… sugar.
Gout has often been blamed on excessive consumption of meat. This is because the uric acid that causes gout is a breakdown product of purines, a building block of protein, that is highly concentrated in meat.
However, as with all nutritional epidemiology studies, it is impossible to separate eating meat from observational healthy user bias, or from associated refined grains or alcohol intake.
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Therefore, epidemiology studies cannot prove that meat causes increased gout risk. In fact, one study showed that vegans had higher uric acid levels that meat eaters and fish eaters, thus potentially placing them at the highest risk for gout attacks.
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Eating more protein (like meat) seems to increase the excretion of uric acid from the kidneys, through the urine, thus not having much of an effect on the blood uric acid levels… or the risk of gout.
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Some weak observational studies, especially those in the United states, show an association between meat intake and elevated uric acid levels.
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Others, such as one in Taiwan, show no such association.
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Why the difference? We don’t know for sure, but one explanation could be the prevalence of metabolic syndrome or the consumption of sugar. Therefore, the rest of the diet may matter more than the consumption of meat itself.
As there is a very strong connection between hyperuricemia, gout, obesity, type 2 diabetes and metabolic syndrome, it’s possible that they are all primarily caused by the same thing: sugar and other refined carbohydrates.
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In fact, high blood levels of insulin – a consequence of a diet high in refined carbs – has been shown to increase uric acid levels, probably by decreasing the excretion of uric acid by the kidneys.
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There is a striking history of gout suddenly becoming common in populations just as sugar consumption started to rise sharply (e.g. in Britain during the eighteenth century, paralleling the birth of the country’s sugar industry).
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There’s also experimental evidence, showing that consuming fructose (a main component of sugar) increases levels of uric acid in the body.
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Since alcohol and fructose are metabolized in similar ways by the liver, it is possible that they also increase uric acid levels in the same way.
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Short term studies show a temporary rise in uric acid during the first few weeks when starting a strict (i.e. keto) low-carb diet. This effect seems to disappear after about six weeks, with uric acid returning to baseline or even lower.
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Almost all of my patients who are successful on low-carb diets eventually become gout-free and have low uric acid levels…
Studies show no significant change in uric acid levels in people doing a low-carb diet over several months or years.
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The exception is one study that actually showed uric acid going down significantly after 6 months on low carb, suggesting it may decrease the risk of gout.
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After dozens of high-quality studies comparing low-carb diets to other diets, there seems to be none noticing any obvious difference in the risk of gout, although no study has focussed on this specific question in detail.
Doctors regularly treating patients with low-carb diets do not notice a sharp increase in gout episodes even during the first time period.
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So if there exists an increase in risk during the first few weeks it is likely small.
