Tart Cherries are one of nature’s unsung healing agents, able to help the body recover naturally from a myriad of different ailments.
A Cherry on Top? The Rise of Tart Cherry
Though proverbially, the cherry has always been on top, medicinally, it has always laboured near the bottom. While bilberry was accumulating studies on eye health, hawthorn berries were accumulating studies on heart health, cranberries were achieving fame for urinary tract health and blueberries were resolving high blood pressure and staking a claim to the antioxidant crown, cherries were seen as simply pleasurable, placing the entire weight of their health claim on a single half century old study showing that they could prevent attacks of gout .
In the past half dozen years, though, all that has changed, and the humble cherry is moving up the herbal hit list. Maybe there really is a cherry on top.
The first early gout study took sixty-two years to be replicated. A modern study of 633 gout sufferers found that eating cherries reduced the risk of having a gout attack by 35% and that supplementing a cherry extract reduced the risk by an even more impressive 45% . After waiting over half a century, the next study took only one year to follow. This study gave gout sufferers a cherry juice concentrate (1tbsp=45-60 cherries) while they continued to take their medication. In the first part of the study, more than 50% of the cherry group were attack free at 60 days and could cut back on their meds. In the second, attacks were reduced by 50% in half the people taking cherry juice for four months or longer .
Soon it would be discovered that cherries could do more than prevent attacks of gout. In truly surprising research, cherries, it turned out, treated insomnia. The first evidence came from a double-blind study of fifteen healthy, elderly people with insomnia. Their average age was 71.6 years. For two weeks, they drank either two 8 ounce servings of Montmorency tart cherry juice and apple juice or a similar looking placebo drink. Though at the end of the study, the people still had insomnia, those who drank the cherry juice had moderately improved sleep. They experienced significant improvement on the Insomnia Severity Index, on how long it took them to fall asleep, on how often they woke up and on total sleeping time.
A second study found out how tart cherries treated insomnia. This double-blind study gave twenty healthy men and women 30mL of tart Montmorency cherry juice concentrate in 200mL of water twice a day for seven days. The dose was equivalent to approximately 90-100 tart cherries. Compared to a placebo fruit drink, the tart cherry juice significantly increased melatonin by about 16%. Cherries, it turned out, were improving sleep because they were a natural source of the sleep hormone melatonin. Compared to a placebo, the cherry group significantly increased the time spent in bed, had a significant 34 minutes more sleep per night and a significant 5-6% increase in the time in bed spent sleeping. The people on the cherry juice also spent significantly less time napping . An earlier study had also found that Jerte Valley cherries increased melatonin and improved sleep.
Later, a fourth study would also find that, compared to placebo, a cherry product improved sleep efficiency, time taken to fall asleep, number of awakenings and total sleep time and that it increased melatonin.
Surprisingly, then, in a novel use of cherries, there is evidence that they improve sleep because they are a natural source of melatonin.
In the same year the studies began to appear on insomnia, studies began to appear that demonstrated benefits for cherries for exercise. According to double-blind research on 54 healthy runners, when 355 mL of tart cherry juice was taken twice a day for seven days prior to a long distance run and again on the day of the race, the runners had significantly smaller increases in muscle pain than runners given a placebo cherry drink.
Subsequent studies would show that cherries improved the free radical damage and inflammation that resulted from exercise. In the first, twenty recreational marathon runners drank either cherry juice or a placebo for five days prior to a race and continued drinking it until two days after the race. Strength recovery was significantly faster in the cherry group. Furthermore, inflammation was significantly reduced and total antioxidant status was significantly greater in the cherry group. A subsequent double-blind study would give either 30 mL Montmorency cherry concentrate (equivalent to about 90- 110 whole cherries) or a placebo in 100mL water twice a day for a week to sixteen healthy male cyclists. Blood samples were taken after the cyclists completed high intensity exercise. Markers of free radical damage and inflammation were again significantly better in the cherry group.
Although exercise is good for every aspect of health, prolonged exercise can suppress immunity. Because of this immune suppression, prolonged exercise is associated with increased respiratory infections. So, researchers tried giving twenty recreational marathon runners either tart Montmorency cherry juice or a placebo, starting five days before they ran their marathon and continuing until two days after they were finished. The dose of cherry juice was 236mL of fresh-pressed Montmorency tart cherry combined with apple (equal to 50-60 cherries) twice a day; the placebo was the same amount of a sugar-free fruit flavoured drink that looked like cherry juice. As in the earlier studies, the cherry juice significantly reduced inflammation after the race. C-reactive protein, a marker for inflammation, increased significantly less in the cherry juice group. Importantly in this study, both the number and the severity of upper respiratory tract symptoms (URTS) were significantly worse in the placebo group. Only the placebo group suffered more URTS after the race: while 50% of the runners who took the placebo had URTS at 24 and 48 hours after the race, not one of the runners who drank the cherry juice did.
High Blood Pressure
The most recent study on cherries has discovered yet another benefit. Cherries benefit blood pressure. The just published study was a double-blind study of fifteen men with early high blood pressure: that is, they had either systolic blood pressure of 130 mmHg or higher, diastolic blood pressure of 80 mmHg or higher, or both.
They were given a single 60mL dose of concentrated Montmorency tart cherry juice, which is equivalent to about 180 cherries, diluted in water or a fruit flavoured placebo drink. Their blood pressure was measured five times over the next eight hours after this single administration of cherry juice. Systolic blood pressure was significantly lower for three hours after drinking the tart cherry drink compared to the placebo. The greatest reduction in systolic blood pressure was 7 mmHg two hours after drinking the cherry juice. The lower readings occurred when levels of tart cherry polyphenols (antioxidant flavonoids) were increased, suggesting that the blood pressure benefit may be due to the polyphenols.
With at least a dozen studies in the past half dozen years showing that tart cherry lowers uric acid and prevents painful gout attacks, raises melatonin and promotes sleep, reduces inflammation and free radical damage and promotes recovery and immunity after exercise and increases polyphenol antioxidants and lowers blood pressure, perhaps, after all these years, there really is a cherry on top.