Written By: GreenMedInfo Research Group

Could a nutritious garden-variety fruit pave the path to sounder sleep? Emerging research suggests getting your dose of tomatoes at dinnertime may bolster the body's own production of melatonin

This multifaceted sleep-signaling substance and powerful antioxidant wanes as women age, contributing to increased insomnia and associated health risks.1

Insomnia afflicts up to 20% of the population at some point in their lives.2 Women especially endure sleep difficulties following menopause, with prevalence up to 3.4 times higher than premenopausal counterparts.3 Shifting hormones during this transition can impair circadian regulation of sleep-wake cycles already prone to dysfunction with older age.4 Hot flashes and declining levels of the hormone melatonin are key culprits in this pattern. Melatonin plays many crucial roles, including acting as the quintessential regulator of healthy sleep cycles and conveying cues to initiate drowsiness at night.5 It also serves as a potent antioxidant, neutralizing cell damage that accelerates aging.6

Melatonin production occurs during evening darkness in response to cues from the suprachiasmatic nucleus (SCN), the brain's central clock. Its synthesis and release from the pineal gland subsequently dips during daylight. Postmenopausal women demonstrate significantly lower nighttime melatonin levels compared to premenopausal women.7 Researchers speculate menopausal hormonal shifts slow synthesis pathways. Restoring melatonin rhythmicity may offer therapeutic potential not only for improving sleep directly but also ameliorating downstream impacts of insomnia.

Researchers in Taiwan recently evaluated whether consuming melatonin-rich foods at night could raise melatonin levels and alleviate sleep problems in postmenopausal women. Beefsteak tomatoes contain substantial melatonin, roughly 7.5 times more than other tested fruits and vegetables.8 In an 8-week randomized controlled trial, 36 obese and insulin resistant women with diagnosed poor sleep ate 250 grams of beefsteak tomato two hours before bedtime. The control group received nutritional counseling but maintained usual diets without tomatoes.

Researchers analyzed participants' sleep via the Pittsburgh Sleep Quality Index (PSQI), an extensively validated questionnaire measuring seven domains: duration, efficiency, latency, quality, disturbance, medication use, and daytime dysfunction. Scores above 5 indicate poor sleep. They also tested morning urine samples for 6-sulphatoxymelatonin levels. As melatonin metabolizes rapidly, this urine metabolite accurately reflects circulating melatonin overnight.

Remarkably, while both groups exhibited poor sleep initially, the women eating tomatoes slept over 10 minutes longer and fell asleep 12 minutes quicker by week eight. They also reported enhanced sleep quality, fewer disturbances, and better daytime function versus baseline. In contrast, the control group showed limited sleep duration and disturbance improvements only.

Even more compelling, participants' post-intervention urine tests revealed dramatically higher aMT6s levels after eating tomatoes for eight weeks (918 vs 96 pg/mg creatinine)9 - indicating the vegetable truly augmented endogenous melatonin production at night. Given tomatoes' rich supply, they likely provided sufficient precursors to jumpstart synthesis processes attenuated by ovarian aging.

Obese postmenopausal women commonly experience metabolic dysregulation that perturbs sleep.10 By reestablishing circadian melatonin rhythmicity with a simple dietary change, tomatoes offer an easily accessible and sustainable remedy to reinforce the body's sleep-wake orchestration. Given insomnia closely associates with hypertension, diabetes, depression, dementia, and stroke,11 the public health implications of this fruitful discovery could prove substantial. Certainly surrendering to slumber may now be as easy as embracing a vibrant vegetable instead of a prescription pill.

Of course, longer and larger trials should attempt to replicate these exciting preliminary results before drawing definitive conclusions. Participants' diets were not rigorously controlled, which may have impacted outcomes. Future studies could also measure dim light melatonin onset to further characterize tomatoes' effects on circadian timing. Investigating optimal dosing strategies and standardized preparations may strengthen real-world utility. Still, when it comes to banishing insomnia without medications, starting with salad at suppertime seems a reasonable approach to a better night's sleep.

© February 13th 2024 GreenMedInfo LLC. This work is reproduced and distributed with the permission of GreenMedInfo LLC. Want to learn more from GreenMedInfo? Sign up for the newsletter here //www.greenmedinfo.com/greenmed/newsletter.