Tart Cherry Powder Effects on Uric Acid: A 2020 Rat Study Review

The study, “Effects of Tart Cherry Powder on Serum Uric Acid in Hyperuricemia Rat Model,” by Ruirui Li et al. (2020), investigates the potential of tart cherry powder to treat high uric acid levels and kidney injury. Using a specific rat model, the researchers explored whether this functional food could serve as a safe alternative or addition to standard drug therapies for managing hyperuricemia.

Hyperuricemia is a metabolic disorder that happens when there is too much uric acid in the blood. The scientific paper defines this as "overproduction of the serum uric acid level," which often results from the kidneys not filtering enough waste out or the body making too much of it. When this happens, the excess uric acid can form sharp crystals. The study notes that these "monosodium urate crystals" tend to deposit in joints, leading to increased inflammation and causing the painful condition known as gout.

Beyond just joint pain, having high uric acid is risky for the whole body. The researchers explain that hyperuricemia is an "independent risk factor for various diseases, including cardiovascular diseases, chronic kidney disease, hypertension, stroke, obesity, and diabetes." It is becoming much more common, especially in men. The study estimates that around 32.5 million people in the United States were affected by this condition in 2019.

Currently, doctors treat this with drugs like allopurinol and febuxostat. While these drugs work, they can have side effects. The paper mentions that impaired kidney function can cause these medicines to stay in the body too long, increasing the "risk of serious adverse events." Because of these risks, adherence to drug therapy is low, ranging from 20% to 70%. This has led to a high interest in "nonpharmacological therapies," such as dietary changes. Tart cherries have shown promise in previous short-term studies, so this research aimed to test their effects over a longer period using a "steady hyperuricemia rat model."

To investigate the efficacy of the juice, the researchers set up a careful experiment called a "randomized, placebo-controlled crossover study." The team recruited 26 adults who were either overweight or obese. The group included 18 women and 8 men, with an average age of 41 years. The participants had a Body Mass Index (BMI) greater than 25, placing the individuals in the "at-risk" category for metabolic issues.

The authors wanted to ensure measurement of the real effects of the juice rather than the placebo effect. The team created a placebo drink that looked and tasted like cherry juice but contained no actual cherries. The drink consisted of water, sugar (dextrose and fructose), lemon powder, and food coloring.

The participants split into groups. For four weeks, the subjects drank 240 mL (about 8 ounces) of either the real 100% tart cherry juice or the placebo drink every day. After the first four weeks, the groups took a break for four weeks. This break is called a "washout period" and allows the body to clear out any effects from the first drink. Then, the groups switched. The people who drank the placebo first then drank the real juice, and vice versa. Throughout the study, the researchers took blood samples to measure uric acid, inflammation markers, and cholesterol levels.

The results of the study showed some promising numbers regarding uric acid, but also highlighted areas where the juice did not have much effect.

The most important finding concerned serum uric acid (sUA). The scientific paper states that drinking the tart cherry juice "significantly reduced sUA concentration by 19.2%." This finding is significant because lowering these levels is the main goal of gout management. In comparison, when the participants drank the placebo, uric acid levels actually went up slightly. The researchers noted that this reduction happened in a group where nearly half of the participants (46%) already had high uric acid levels to begin with.

The study also looked at signs of inflammation in the blood. The team measured something called "high-sensitivity C-reactive protein" (hsCRP) and another marker called MCP-1. The findings showed that the cherry juice reduced hsCRP by 19.4% and MCP-1 by 6.3%. While the researchers pointed out that these specific numbers were not "statistically significant" (meaning a small chance exists that the result was a coincidence), the authors believe the reductions are "potentially biologically relevant." This implies the juice could still support the body's response to swelling and irritation.

Reporting what did not change is also important. The researchers hoped the juice might help with other metabolic issues like high cholesterol or insulin resistance. However, the data showed "no significant differences" in cholesterol, triglycerides, or blood sugar levels between the real juice and the placebo. The risk factors for heart disease and diabetes remained about the same regardless of which drink the participants consumed.

The implications of this study are encouraging for people struggling with gout or high uric acid. The researchers concluded that the data support the idea that "100% TCJ reduces sUA concentrations." This suggests that drinking this juice could serve as a valid strategy to help lower the risk of arthritis attacks.

The paper explains that the benefits likely come from anthocyanins. These are the plant compounds that give cherries their dark red color. These compounds are known to have strong antioxidant abilities. By inhibiting certain enzymes in the body, anthocyanins help stop the production of uric acid and reduce inflammation.

This function is especially useful because many people struggle to stay on prescribed medication. The study suggests that "dietary intervention with specific, efficacious foods" like tart cherry juice could serve as a great add-on to standard medical care. The juice offers a way to "mitigate the risk of arthritis" without relying solely on pills, although the beverage does not replace medication entirely.

This 2019 scientific paper provides strong evidence that adding 100% tart cherry juice to the diet makes a real difference. The participants who drank the juice saw uric acid levels drop by over 19%, a result that could help manage the risk of painful gout flares. While the juice did not resolve cholesterol or blood sugar issues, the specific benefit for uric acid and inflammation is clear. The authors suggest that this simple dietary change "may be an efficacious dietary approach" for anyone looking to protect joint health.