The study, “ Effectiveness of Cherries in Reducing Uric Acid and Gout: A Systematic Review,” by Pei-En Chen et al. (2019) investigates the potential benefits of cherry consumption for managing gout and hyperuricemia. Through a systematic analysis of six relevant papers, the researchers determined that regular intake of cherry products is associated with a significant reduction in serum uric acid levels and a decreased risk of painful gout flare-ups.

Gout is a condition characterized by the crystallization of uric acid in or around the joints. This buildup leads to what the scientific paper describes as discomfort and intense pain. It is a frequent consequence of inflammatory arthritis and affects the quality of life for many people. Usually, patients diagnosed with gout or hyperuricemia (the medical term for high uric acid levels) must undergo continuous drug therapies. Doctors commonly prescribe medications like allopurinol and febuxostat. These drugs work by inhibiting the activity of xanthine oxidase to lower urate levels.

However, interest in how diet can help is growing. Cherries are a nutritious fruit packed with a variety of chemical compounds. The study authors note that previous research suggests cherries may benefit patients with insomnia, sore muscles, and even chronic conditions like diabetes and cardiovascular disease. From the perspective of alternative medicine, diet is often viewed as a complementary factor associated with gout. This link exists because the incidence of gout is often higher among people with obesity or those who consume large amounts of alcohol, sugar, or purine products.

While many different fruits are considered beneficial for reducing uric acid levels, solid evidence is required to confirm if these non-drug methods actually work. Several previous studies have reported that cherry extract and cherry juice could serve as a supplement to help patients. The specific objective of this systematic review was to assess the effectiveness of cherry products in reducing uric acid levels and mediating the incidence of gout attacks.

The researchers conducted a thorough and careful search for relevant studies to investigate this topic. They searched through major medical databases, including PubMed, Embase, and the Cochrane Library. The team looked for any relevant research published from the beginning of these databases up until August 15, 2019. To ensure no important data was missed, the authors did not place any restrictions on the language of the papers.

The team used specific guidelines to evaluate the quality of the research found. They utilized the PRISMA statement and checklist to evaluate the risk of bias and the Cochrane Collaboration tool to assess methodological quality. After scanning many databases using terms like "gout," "hyperuricemia," and "cherry juice," the researchers identified a total of six studies that met the strict criteria. These six studies specifically addressed the relationship between cherry intake and gout. Five of these studies were conducted in the United States, and one was conducted in the United Kingdom.

The researchers extracted key data from these studies, including the study design, the number of subjects, the ages of participants, and the outcomes. Two authors independently reviewed the quality of the papers. The reviewers checked for potential issues, such as whether the allocation of treatment was concealed and if the participants were blinded to the beverage consumed. The review found that the most common sources of potential bias in these studies were inadequate allocation concealment and sequence generation. Because only a few papers existed and the study designs were very different, the researchers determined that a mathematical meta-analysis was impractical. Instead, the team performed a qualitative assessment of the data.

The review of these six studies provided significant insights into how cherries interact with the body. The results covered the impact on gout attacks, the changes in uric acid levels, and how quickly these changes occur.

Two of the included studies focused specifically on the correlation between eating cherries and the frequency of gout attacks. One major study by Zhang et al. in 2012 involved 633 patients diagnosed with gout. This group was predominantly male (78%) and White (88.2%), with 3% Black and 7.4% identified as "Other." The study found that after ingesting cherries for a period of two days, there was a significant decrease in the risk of gout attacks. Specifically, the risk of having an attack dropped by roughly 35%. The researchers noted that cherry juice and extract produced consistent results across various groups, regardless of sex, obesity status, alcohol use, or the use of other gout medications.

Another study by Singh et al. in 2015 looked at 220 gout patients. In this group, 74% were male, and 79% were White. The study reported a number of positive outcomes. Cherry intake showed significantly stronger effects in producing fewer gout flares compared to taking no supplements. Patients reported fewer flare-ups than in the previous month and a lower likelihood of experiencing any flare-ups at all.

The review also examined studies that measured the actual concentration of uric acid in the blood. A study by Martin and Coles in 2019 involved 26 participants who were overweight or obese. These participants consumed tart cherry juice for four weeks. The findings were clear: TCJ significantly reduced serum uric acid concentration by 19.2%. This indicates that the juice had a strong, measurable biological effect on the participants.

However, the results were not identical across all studies. A study by Schlesinger et al. compared the effects of cherry juice against pomegranate juice. The participants included a mix of backgrounds, with 11 Caucasians, 1 Asian, 1 Hispanic, and 1 African American. The researchers found that while both juices slightly decreased plasma urate levels, the effects of the cherry juice were less pronounced. In this specific small study, the changes did not reach the level of statistical significance.

The researchers also looked at how much time is required for cherries to work. A study by Jacob et al. monitored 10 healthy women with an average age of 29.9. The study observed a significant reduction in plasma urate levels for a period of 5 hours following the consumption of cherries. The concentration of urate at 5 hours after the dose was significantly lower than at baseline.

Another study by Bell et al. involved 12 healthy participants. This study observed a significant reduction in serum urate at just 2 hours after cherry ingestion. This suggests that the body absorbs the beneficial compounds relatively quickly, leading to a rapid response in blood chemistry.

The synthesis of these findings points to a positive link between cherries and gout management. The scientific paper concludes that current evidence supports an association between cherry intake and a reduced risk of gout attacks. The ingestion of cherries demonstrated effectiveness in lowering urate levels in the reviewed studies, which is a key goal for anyone suffering from this condition.

The researchers attribute this effectiveness to the chemical composition of the fruit. Previous studies have linked the suppression of gout-related inflammation to the anti-inflammatory properties of cherries. Specifically, cherries contain high levels of anthocyanins. The paper explains that key enzymes involved in inflammation, such as cyclooxygenase 1 and 2, are strongly inhibited by anthocyanins from cherry extract. Furthermore, cherry extract has been shown to reduce the levels of various cytokines in affected joints. The cherries appear to help inhibit the production of substances that cause swelling and pain.

This is critical because failing to treat high uric acid can lead to severe health issues. The paper warns that untreated hyperuricemia increases the prevalence of mortality due to cardiovascular disease as well as complications related to diabetes. Therefore, controlling diet to manage urate accumulation is vital for long-term health.

However, the authors also highlight some limitations. The team noted an inability to conduct effective meta-analysis due to a lack of relevant studies. There was simply too much variation in how the previous studies were designed and measured. Additionally, most of the participants were from the US and the UK. The lack of data from individuals of different races may have narrowed the applicability of this study, meaning readers should be careful about assuming these results apply perfectly to everyone globally.

This systematic review offers a promising outlook for those living with gout. The data indicate that consuming cherries, whether as a juice or extract, is linked to a noticeable drop in painful flare-ups. For those looking for natural ways to support health, the study highlights that the antioxidant and anti-inflammatory effects found in cherries play a real role in lowering uric acid. While more research covering a wider variety of populations is needed to fully understand the impact, the current proof suggests that cherries are a valuable, nutritious option to consider alongside standard medical treatments.