The study, published in the Journal of the International Society of Sports Nutrition, is said to be the first to provide “encouraging evidence” of the potential benefits of tart cherries to reduce URTS possibly caused by exercise-induced hyperventilation or other factors.
“Despite no apparent change in cortisol or mucosal immunity between groups, runners that consumed Montmorency cherry juice had a lower CRP response at 24 and 48 h post–Marathon and had zero incidence of reported URTS up to 48 h after the Marathon, suggesting that cherry juice attenuated the exercise-induced inflammatory response and the subsequent development of URTS compared to the placebo group following the race,” wrote researchers based in the UK.
The study was led by Lygeri Dimitriou from the London Sport Institute at Middlesex University.
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The study supports a number of other studies reporting the potential benefits of cherry, and tart cherries, in particular. A previous study (Journal of Nutrition, 2006, Vol. 136, pp. 981-986) reported that daily consumption of 45 cherries could reduce circulating concentrations of inflammatory markers, with the researchers proposing that the flavonoids and anthocyanins in the cherries exert an anti-inflammatory effect and may lessen the damage response to exercise.
According to the researchers, a 30 mL dose of the tart cherry concentrate used in the new study is equivalent to about 90 whole Montmorency tart cherries. The concentrate is reported to contain 9 mg/mL of anthocyanins.
The new study looked at the potential effects of tart cherry juice on markers of stress, immunity, and upper respiratory tract symptoms in 20 marathon runners. The participants were randomly assigned to consume 572 ml per day of a tart cherry-apple juice drink (Cherrypharm Inc., New York) or placebo for five days before running a marathon. The participants also consumed it the beverages on the day of the race and for 48 hours post-race.
The daily intake was equivalent to 100-120 whole cherries and contained at least 80 mg of anthocyanins.
Results showed that CRP levels, a marker of inflammation, were significantly decreased in the cherry group, compared with placebo.
Participants in the cherry group had no URTS but 50% of the placebo group reported URTS at one and two days after the race.
“The results of this pilot study showed that a Montmorency cherry juice blend appears to protect the URT from inflammatory symptoms caused by infectious and non-infectious agents, by possibly reducing the exercise-induced pulmonary inflammation,” wrote the researchers. “Modulation of the exercise-induced pulmonary inflammation by natural plant products might represent an attractive strategy to protect or alleviate the URT from inflammatory symptoms.
“Considering the limited sample size and healthy state of this study’s cohort, further studies with a larger sample size and participants with asthma, atopy, allergic rhinitis, exercise induced bronchoconstriction, airway hyper-responsiveness, and other pulmonary pathologies could be performed to explore the potential of cherries and other functional foods that might exert a similar effect.”
Source: Journal of the International Society of Sports Nutrition
2015, 12:22, doi:10.1186/s12970-015-0085-8
“Influence of a montmorency cherry juice blend on indices of exercise-induced stress and upper respiratory tract symptoms following marathon running—a pilot investigation”
Authors: L. Dimitriou, J.A. Hill, A. Jehnali, et al.