Some consults are straightforward. Others take more digging. When I’m consulted for high uric acid levels, it’s one of the trickier ones. Traditional dietary advice — like restricting high-purine foods — often targets items rarely eaten in the average Canadian diet (think organ meats, game meat, or even horse meat). So what should we realistically recommend?
How many studies did the meta-analysis include?
The review included 41 studies — a mix of observational and interventional designs.
Which diets lowered uric acid levels?
The authors reported that Plant-based diets led to:
- A modest reduction in serum uric acid levels in interventional trials.
- A lower risk of hyperuricemia in people with normal uric acid levels.
However, cross-sectional studies did not show consistent benefits, likely due to the less controlled nature of dietary reporting. The authors suggest that intervention studies were better able to produce meaningful dietary changes, which may explain the differences.
How much can plant-based diets reduce uric acid levels?
Intervention studies reported a mean reduction of -0.24 mg/dL (95% CI: -0.42 to -0.06).
There was a stronger association in men than in women.
In individuals with normal uric acid levels, the authors reported that plant-based diets reduced the odds of hyperuricemia by 25% (OR 0.75, 95% CI 0.67–0.83).
How did the authors define plant-based diets?
The authors defined a diet as plant-based when over 50% of the major food items came from plant sources, including:
- Fruits and vegetables
- Whole grains
- Legumes
- Nuts and seeds
- Herbs and spices
Which diets did studies link to higher uric acid levels?
- The authors didn’t find that animal-based dietary patterns raised serum uric acid levels, but they did link them to a higher risk of hyperuricemia (OR 1.38, 95% CI 1.2–1.59)
- Mixed dietary patterns (neither fully plant-based nor animal-based) were associated with increased uric acid levels in observational studies, but not in interventional studies.
Animal-based diets were defined as those where more than half of the major food components came from:
- Meat
- Poultry
- Fish
- Eggs
- Dairy
Why might plant-based diets reduce uric acid levels?
Plant-based diets are rich in nutrients and compounds that may lower uric acid, including:
- Vitamin C (may reduce uric acid reabsorption in the kidney)
- Vitamin E
- Carotenoids
- Isoflavones
- Dietary fiber (may increase fecal excretion of uric acid)
Why might animal-based diets raise uric acid levels?
- These diets tend to be higher in purines, which metabolize into uric acid.
- High intake of animal-based foods is also linked to obesity and insulin resistance, both of which may contribute to higher uric acid levels and increased gout risk.
Key Takeaways for Clinical Practice
- Encouraging a diet that includes at least 50% plant-based foods may lead to modest reductions in serum uric acid.
- The absolute reduction is small, but the overall health benefits of a more plant-focused diet make it a reasonable, low-risk recommendation. Plus, it aligns with many other kidney friendly diet recommendations for managing acidosis and potassium.
- Rather than focusing on foods patients rarely eat, guiding them toward more fruits, vegetables, legumes, and whole grains may be a more practical and sustainable approach.
