As tart cherries are known to contain several antioxidant and anti-inflammatory compounds, Connolly et. al. (2006) tested the efficacy of tart cherry juice in preventing the symptoms of muscle damage from exercise by administering a cherry juice blend or placebo to fourteen male college students twice a day for eight days, incorporating strength exercises on the fourth day and recording elbow strength and pain before and after exercise. A second trial was repeated two weeks later. Pain and loss of strength were significantly lower in the cherry juice trial than the placebo. Strength loss after treatment with the placebo was 22% and only 4% after treatment with cherry juice. These results suggest that tart cherry may be effective in decreasing some symptoms associated with muscle damage following exercise. Another study by Howatson et. al. (2010) evaluated tart cherry for its efficacy in helping recovery and reducing muscle damage following marathon running by measuring biomarkers of muscle damage before and after the marathon. This study showed significantly faster isometric strength recovery and reduced inflammation in participants given tart cherry juice. Total antioxidant status (TAS) was also measured and shown to increase following tart cherry consumption. This suggests that by increasing TAS and reducing inflammation, tart cherry juice may aid post-exercise muscle function recovery. In another study, Kuehl et. al. (2010) evaluated the efficacy of tart cherry in reducing post-exercise muscle pain in runners. Participants were given tart cherry juice or placebo twice each day for seven days before a race and on the day of the race and reported their pain level on a 100 mm Visual Analog Scale (VAS) at baseline, before the race, and after the race. Compared to the placebo group, participants who received tart cherry juice reported a significantly smaller increase in pain, higher willingness to use the drink in the future, and higher satisfaction with the reduction in pain, which they attributed to the drink.
In addition to its anti-inflammatory effects in relation to exercise, tart cherry has also been evaluated for use in reducing inflammation associated with osteoarthritis. A study by Sleigh et. al (2012) evaluated tart cherry’s effects on serum inflammation biomarkers among women ages 40-70 with inflammatory osteoarthritis. Tart cherry juice or placebo was administered twice each day for 21 days. Serum inflammation biomarker levels were measured before and after drinks were administered. All measured serum biomarker levels—particularly TNF-α, which showed a statistically significant change (P < 0.05) — suggesting decreased inflammation. Furthermore, in a high-inflammation subset of twelve women, a statistically significant difference was measured in TNF-α and CRP, suggesting reduced inflammation in all subjects given tart cherry juice instead of placebo.
Gout occurs when elevated uric acid levels cause the formation and accumulation of crystals around a joint, causing pain and swelling. Tart cherry has been used for decades to treat the symptoms of gout, though evidence was largely anecdotal until modern research explored its efficacy in treating this condition. In 2011, Martin et. al. conducted a study of tart cherry’s effects on serum uric acid levels and biomarkers of inflammation in ten obese and overweight participants. Participants were given tart cherry juice or placebo every day for four weeks each trial with a two-week washout period between trials. Inflammatory markers were reduced, and reduced serum uric acid levels were observed in seven out of ten participants.
The capacity of older adults to resist oxidative damage from acute stress is significantly impaired compared with young adults, likely contributing to increased mortality resulting from trauma, as well as increased susceptibility to degenerative diseases, including Alzheimer’s disease, cancer, and atherosclerosis. Consumption of foods containing high levels of anthocyanins may mitigate the tendency of oxidative damage to increase with age. Traustadóttir et. al. (2009) evaluated the efficacy of tart cherry juice in improving the capacity of older adults to resist oxidative damage during acute oxidative stress. Twelve participants were given either tart cherry juice or placebo twice daily for two weeks. Trials were separated by a four-week washout period. To create acute oxidative stress, forearm ischemia-reperfusion (I/R) was induced. The change in F2-isoprostanes (F2-IP), a sensitive and reproducible indicator of acute oxidative damage, was measured following I/R. Basal urinary excretion of oxidized nucleic acids was also measured as an indicator of oxidative stress. A significant increase in F2-IP occurred in response to I/R, and this response was significantly reduced in participants who consumed tart cherry juice. Basal urinary excretion of oxidized nucleic acids was also reduced in participants who consumed tart cherry juice.