We have a guest blogger today! Becca Blumberg from Colorado State University has written an awesome article on tart cherry juice and it's effects on training and performance. Enjoy!
If you’ve been reading anything on sports nutrition lately, you’ll have heard about tart cherries. They are the newest performance-enhancing superfood. Proponents claim that just by swigging some cherry juice, you’ll perform better and recover faster. Is this just hype, or are there some truths to the claims?
What AREÂ tart cherries and what makes them special?
The cherries that have been studies by scientists and promoted in blogs everywhere are called Montmorency Tart Cherries. These are the same cherries often used in cherry pies, not the sweet cherries that we eat like candy each summer. Now the most popular tart cherry in the United States and Canada, they have been cultivated since the times of ancient Rome and are named for an area of France.
Tart cherries, as well as sweet cherries and other berries, are high phytonutrients. These are compounds which we find in plants but can’t classify into our usual nutrient categories. These compounds typically have important antioxidant and anti-inflammatory benefits, and those found in cherries are no exception. The acanthocyanins which give the fruit its color act in the body in a similar way to ibuprofen and naproxene, the active ingredients in Advil and Aleve [1]. The fruit also has antioxidant properties similar to Vitamin E [1]. Other compounds have benefits potentially important in heart health [2]. These same compounds also give the cherries their tart taste, which is why the Montmorency cherry has been the focus of research.
Can cherry juice help me perform better and recover faster?
Research into the effects of tart cherry juice on athletic performance has just begun. The biggest potential benefit is the ability of those acanthocyanins to act as natural pain relievers. This would allow for faster recovery from workouts due to decreased muscle and joint pain.
An early study of tart cherry juice supplementation suggested that 2 12-oz servings a day reduced pain and loss of strength following a lab test where participants contracted the muscles around the elbow to exhaustion [3]. Further research in runners suggested that taking two 8-oz servings of tart cherry juice during the week leading up to a race reduced muscle pain during running and improved recovery [4, 5].
Another study supplemented runners with powdered cherry extract or placebo for 10 days leading up to a half marathon. Those receiving the cherry supplement came closer to predicted race times, reported less muscle soreness following the race, and lower levels of immune system activation, inflammatory response, and muscle breakdown in their blood. The cherry group also showed faster reductions in reported muscle soreness than the control group [6]. However, similar research in water polo players did not find differences between cherry supplementation and the placebo group [7]. Clearly, more research is needed to further investigate benefits of tart cherry on performance and recovery.
What other benefits might there be?
No one wants to get sick and miss key training days, or worse, to feel under the weather on race day. The anti-inflammatory properties of cherries may help keep the respiratory inflammation associated with prolonged endurance exercise at bay. Runners in the 2008 London marathon who took two servings a day of tart cherry juice in the days leading up to the race reported fewer respiratory symptoms following the race and had lower levels of C-reactive protein, a marker of inflammation, in their blood compared to runners receiving a placebo. However, no differences in protective antibodies were found in saliva from the runners [8]. This is a promising result but more work needs to be done.
Another phytochemical found in tart cherries is melatonin. You’ve probably heard of this hormone and it’s connection to sleep and circadian rhythms. Many people take it to help combat jet-lag. A study asked 20 people to take either tart cherry juice concentrate or placebo for 7 days. They slept with an in-home sleep monitoring system and filled out sleep diaries during this time. Results indicated that participants who drank the cherry juice slept longer and better, and had higher melatonin levels [9]. And we all know the benefits of sleep in our lives!
How do I incorporate cherry juice into my diet?
If you head to Whole Foods, you’ll find tart cherry juice in many forms … drinks, concentrates, pills, and more. Research needs to continue on which form is best, as well as effective dose and timing relative to workouts and competition. This makes it impossible to make specific recommendations right now.  The studies cited in this blog used mainly cherry juice or concentrate, and we have learned time and again that eating real, whole-food forms of plants is generally best.
It is likely that a number of compounds found in the cherries work together to provide the benefits. While no one food is going to turn you into a superstar or substitute for quality training and nutrition, adding some tart cherries to your diet is not only delicious, it will probably have some benefit for your health. And while there are no guarantees, taking a twice daily dose during race week just might help you recover better from all that hard training and help you perform at your best.
Keep in mind, the juice comes with calories, so it must fit into your overall nutrition plan. If this is a concern, adding the concentrate to some sparkling water or smoothies may help you get the benefits without adding quite as many calories.
Note from Cindy: You can also find tart cherry juice at King Soopers in Colorado. It's in the aisle with sport drinks and soda pop (not the aisle with fruit juice, oddly enough!). The brand I use is Simple Truth.
For Further Reading:
Seeram, N.P., et al., Cyclooxygenase inhibitory and antioxidant cyanidin glycosides in cherries and berries. Phytomedicine, 2001. 8(5): p. 362-9.
Keane, K.M., et al., Phytochemical uptake following human consumption of Montmorency tart cherry (L. Prunus cerasus) and influence of phenolic acids on vascular smooth muscle cells in vitro. Eur J Nutr, 2016. 55(4): p. 1695-705.
Connolly, D.A., et al., Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage. Br J Sports Med, 2006. 40(8): p. 679-83; discussion 683.
Howatson, G., et al., Influence of tart cherry juice on indices of recovery following marathon running. Scand J Med Sci Sports, 2010. 20(6): p. 843-52.
Kuehl, K.S., et al., Efficacy of tart cherry juice in reducing muscle pain during running: a randomized controlled trial. J Int Soc Sports Nutr, 2010. 7: p. 17.
Levers, K., et al., Effects of powdered Montmorency tart cherry supplementation on acute endurance exercise performance in aerobically trained individuals. J Int Soc Sports Nutr, 2016. 13: p. 22.
McCormick, R., et al., Effect of tart cherry juice on recovery and next day performance in well-trained Water Polo players. J Int Soc Sports Nutr, 2016. 13: p. 41.
Dimitriou, L., et al., Influence of a montmorency cherry juice blend on indices of exercise-induced stress and upper respiratory tract symptoms following marathon running--a pilot investigation. J Int Soc Sports Nutr, 2015. 12: p. 22.
Howatson, G., et al., Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. Eur J Nutr, 2012. 51(8): p. 909-16.