Evaluating the Effectiveness of MTC Supplementation in Overweight and Obese Individuals with Sleep Issues

Sleep disorders are common and are often linked to increased inflammation and higher disease risks. Previous studies have suggested that US Montmorency tart cherries (MTC) might improve sleep quality, but there is limited research on their effectiveness in individuals with overweight and obesity. To investigate this, 34 participants with sleep disturbances and a body mass index (BMI) of 32.1 ± 7.0 kg/m² were enrolled in a randomized, controlled, crossover trial. Participants took either 500 mg of MTC capsules or a placebo one hour before bedtime for 14 days.

Sleep data, including total sleep time, deep and REM sleep duration, nap duration, and nocturnal sleep time, were tracked using devices like the Zmachine and Fitbit Inspire 3. Subjective sleep quality and insomnia symptoms were assessed through tools like the Pittsburgh Sleep Quality Index, the Sleep Quality Scale, and the Insomnia Severity Index. Inflammation markers—such as C-reactive protein, TNF-α, IL-6, IL-8, IL-10, and IL-17A—were also measured. The study found no significant effects of MTC supplementation on any of these sleep-related or inflammation markers (p > 0.05). The authors concluded that higher doses of MTC may be needed in future studies involving overweight and obese individuals to observe significant effects.

Commentary by YourDailyFit Columnist Alice Winters

In recent years, Montmorency tart cherries (MTC) have gained considerable attention for their potential sleep-enhancing benefits, driven largely by their naturally occurring melatonin content. However, this study aimed to explore their effects on sleep among individuals with overweight and obesity, a group known to experience more significant disruptions in sleep quality. While the research addressed a relevant gap in the literature, the findings—no significant improvements in sleep metrics or inflammatory markers—are worth scrutinizing from several angles.

Study Design and Population

This randomized controlled crossover study followed a solid design methodology, employing both objective (sleep tracker devices) and subjective (questionnaires) measures to assess the outcomes. The inclusion of individuals with a BMI of 32.1 ± 7.0 kg/m² ensures that the sample is representative of a group at heightened risk for sleep disturbances due to metabolic or inflammatory factors. This was a thoughtful choice given the association between obesity, poor sleep, and higher levels of systemic inflammation.

However, despite the robust design, one critical aspect stands out: the dose of MTC used in the trial. At 500 mg, it is possible that the dose was insufficient for this population, particularly given that earlier research on tart cherry supplementation has often used higher doses or a combination of other sleep-related compounds (such as magnesium or melatonin). The authors themselves suggest that higher doses may be necessary to achieve measurable effects, and this hypothesis warrants further investigation.

Effectiveness of MTC on Sleep

Sleep outcomes, including total sleep time, REM, and deep sleep duration, were monitored using devices like the Fitbit Inspire 3. These are widely used, non-invasive tools, but they can have limitations when tracking sleep stages accurately, especially in individuals with disturbed sleep. The lack of improvement observed in these sleep outcomes raises the question of whether the MTC’s influence on sleep could be more subtle or longer-term than what this short 14-day trial could capture.

Previous research into the melatonin content of MTC has suggested that these cherries may offer some promise in terms of sleep onset latency and overall sleep quality. Yet, this trial failed to replicate those benefits for the participants with obesity or overweight. It is important to note that sleep disturbances in these populations are often linked to complex factors such as hormonal imbalance, stress, and irregular circadian rhythms, and simply increasing melatonin intake might not be enough to counteract these conditions.

Inflammation Markers

The measurement of inflammatory markers like C-reactive protein and various interleukins (IL-6, IL-8, etc.) adds an important layer to this study, as inflammation has been shown to negatively affect both sleep and metabolic health. However, as with the sleep data, the MTC supplementation did not yield significant reductions in these markers. While the failure to see a decrease in inflammation may be disappointing, it is possible that the anti-inflammatory effects of MTC are either not as pronounced as previously suggested or require higher dosages to manifest.

Limitations and Future Research Directions

Several limitations of this study must be addressed in future trials. First, the relatively short duration of the intervention may not have been enough to capture meaningful changes in sleep quality or inflammation. Sleep is a complex, multi-factorial process that can take time to improve with dietary or supplementation interventions. Additionally, larger sample sizes and higher dosages of MTC may provide more conclusive evidence regarding the potential for tart cherry supplementation to enhance sleep and reduce inflammation in overweight and obese individuals.

Furthermore, the study primarily relied on a standard 500 mg dose, which might not have been optimal. Other formulations or synergistic combinations of MTC with other sleep-promoting compounds might yield better results. Future research should also explore whether specific subgroups within the obese population (e.g., those with poor sleep hygiene versus those with metabolic disorders) might benefit from MTC supplementation.

Conclusion

While Montmorency tart cherries have shown some promise in improving sleep in the general population, this study indicates that they may not offer significant benefits for individuals struggling with obesity and sleep disturbances, at least at the dose used. As the authors note, higher doses might be necessary, and further studies should explore longer intervention periods and potential combination therapies. Until then, consumers should approach MTC supplements with cautious optimism, keeping in mind that results may vary depending on individual circumstances and dosing levels.