Tart cherries are a source of antioxidants that are fast emerging as a superfruit. A growing body of evidence has linked the tart cherry to substantial anti-inflammatory benefits, including reduced arthritic and gout pain, and several cardiac benefits.
Prunus cerasus, the sour cherry, is the smallest of the stone fruits.1 It’s sweeter cousins, the Bing, Rainier and Lambert cherries, are usually eaten raw and are slightly larger than sour cherries. Tart cherries are typically reserved for making pies and preserves. So, the next time you feel like indulging in a piece of cherry pie, remember that you can, sort of, justify the indulgence.
Background
Tart cherries contain several potent antioxidants including anthocyanins, which give the cherries their rich, distinctive color.2 In addition, tart cherries have been found to contain a unique set of antioxidative compounds, called superoxide disumutase, that are even more potent than the anthocyanins.2
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Science
Multiple studies have explored using tart cherry juice to offset inflammation. One study examined the effect of cherry juice consumption on rapid-onset oxidative stress. Researchers enrolled 20 recreational marathon runners into a placebo-controlled trial and gave the active treatment group cherry juice prior to and just after the race.3 Isometric strength, muscle enzymes and inflammatory markers were measured in each participant after the marathon. Data showed that the cherry-juice cohort recovered isometric strength faster and showed lower levels of such inflammatory markers as C-reactive protein (CRP) and interleukin-6 than did the placebo group.3
Tart cherry juice was also tested in connection with its ability to relieve oxidative stress and muscle damage in the elderly. One study examined 12 healthy volunteers aged 61 to 75 years.4,5 Each group was given one cup (240 ml) of either cherry juice or flavored water twice daily for two weeks.4,5 Subsequent measurements of oxidized amino acids in urinary output were less in the active treatment group when compared to the placebo, indicating lower levels of cellular damage.4,5
In a small trial, 10 obese volunteers (BMI 27.0-36.0) were studied for potential cardiovascular benefits connected to tart cherry ingestion. Respective cohorts received eight ounces of tart cherry juice or flavored water daily for four weeks.6 At the end of the trial, glucose, high-sensitivity CRP (hs-CRP), total cholesterol, triglycerides, LDL, VLDL, and HDL cholesterol were measured and compared to baseline. Of the measurements, triglycerides and VLDL were significantly reduced in the cherry-juice group, suggesting a reduction in cardiovascular risk.6
Tart cherry juice has also been studied in connection with its effect on arthritic and rheumatologic conditions. In a recently published study, 59 arthritis patients were given 240 ml of cherry juice twice daily for six weeks, and placebo patients were given flavored water.7 At the end of the study, the juice drinkers had significantly decreased hs-CRP levels and pain scores on the Western Ontario and McMaster Universities Arthritis Index (WOMAC), and some subjects noted unsolicited subjective pain relief.7 Study participants were administered the standardized WOMAC questionnaire to accurately determine symptom scores.7
An added benefit of tart cherry juice is that it contains melatonin. Known as the hormone influencing human sleep cycles, melatonin is a potential antioxidant.8 Given this source of exogenous melatonin, studies show improvements in sleep latency, sleep time and overall sleep efficacy.8
Two randomized, placebo-controlled trials studied 35 healthy adults with complaints of sleep-cycle disturbances.8,9 Active-treatment group participants were given daily supplementation of two 8-oz servings of tart cherry juice formulation per day.8,9 Both trials verified improved scores on all study variables, including total sleep time, sleep-cycle efficacy, and sleep latency, as well as urinary excretion of melatonin.8,9
Safety, interactions
Tart cherries contain significant amounts of sorbitol, a sugar alcohol that has been known to trigger symptoms in people with irritable bowel syndrome. Caution should also be used when administering tart-cherry therapy in patients who are taking warfarin, since the high-level of antioxidants may activate warfarin’s antithrombotic action.
Dosage and cost
Tart cherries are available in almost any form — as fresh fruit, dried fruit, juice extracts and powder-filled capsules. The dose considered in most studies is the equivalent of 8 oz of pure cherry juice each day. Many of the extracts and powders on the market are concentrated, reducing the fluid volume to as little as 1 oz. Cost varies with the type of product, ranging from $15 to $50 for a one-month supply.
Summary
Tart cherries are a safe product for individuals seeking a healthy, broad-spectrum antioxidant to add to their daily arsenal.
Sherril Sego, FNP-C, DNP, is a staff clinician at the VA Hospital in Kansas City, Mo., where she practices adult medicine and women’s health. She also teaches at the nursing schools of the University of Missouri and the University of Kansas.
References
1. Alternative medicine supplements page. About.com website.
2. USDA nutrient data laboratory page. United States Department of Agriculture website.
3. Howatson G, McHugh MP, Hill JA, et al. “Influence of tart cherry juice on indices of recovery following marathon running.” Scan J Med Sci Sports. 2010;20:843-852.
4. Connolly DA, McHugh MP, Padilla-Zakour OI et al. “Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage.” Br J Sports Med. 2006;40:679-683.
6. Martin K, Bopp J, Neupane S, Vega-Lopez S. “Tart cherry juice reduces plasma triglycerides and CVD risk in overweight and obese subjects.” J Am Soc Exp Biol. 2010;37:722-740.
7. Schumacher R. “Double blind cross-over study of the efficacy of a tart cherry juice blend in treatment of osteoarthritis (OA) of the knee.” Poster abstract: 2011 American College of Rheumatology Scientific Meeting, Chicago.
8. Howatson G, Bell, PG, Tallent J et al. “Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality.” Eur J Nutr. 2011;13:579-83.
All electronic documents accessed on May 7, 2012
