Melatonin offers new hope for obesity prevention according to recent studies

Recent collaborative research spearheaded by the University of Granada (UGR) has unveiled significant findings regarding the use of melatonin in the prevention of obesity. This research, conducted by a team comprising experts from UGR’s Department of Pharmacology, the Federico Olóriz Neurosciences Institute, the Biosanitary Institute of Granada, and the University of Qatar, has shown promising results in mitigating the risks associated with visceral obesity. This type of obesity is especially concerning as it involves fat accumulation deep within the abdomen, surrounding vital organs, thus posing heightened health risks.

The studies, which were led by Professor Ahmad Agil of UGR and published in the well-regarded journals Antioxidants and Biomedicine & Pharmacotherapy, employed a methodical approach to their experimentation. Using adult rats with obesity and diabetes of both sexes, the research demonstrated that chronic administration of melatonin at a dosage of 10 mg/kg of body weight per day over three months is significantly more effective in preventing obesity compared to short-term treatments. Notably, the treatment resulted in a reduction of visceral fat by approximately 3%. Moreover, the studies highlighted melatonin’s ability to alleviate muscle-fibre atrophy associated with obesity, transform muscle fibre types into a more oxidative and slower phenotype, and increase mitochondrial activity and content—factors which collectively contribute to the observed reduction in weight gain among the treated rats.

An intriguing aspect of the research involved combining melatonin treatment with exposure to slightly cold water, around 17°C, which simulates the average sea temperature. This combination was found to further enhance weight loss, suggesting a potential new approach to managing obesity in humans.

Professor Agil underscored the growing prevalence of obesity, overweight, and type 2 diabetes across both developed and developing nations. He attributed these conditions to poor adaptation of the human genome to current environmental factors that include sedentary lifestyles, consumption of hypercaloric diets, and exposure to persistent artificial light which disrupts natural circadian rhythms and reduces endogenous melatonin levels.

To counter these challenges, Professor Agil recommends several lifestyle adjustments based on individual circadian rhythms. During the day, he suggests exposure to natural light, engaging in physical activity, opting for low-calorie, unprocessed diets, and incorporating thermogenic spices in meals while avoiding snacks between meals and reducing the use of insulating clothing and heating in homes. At night, recommendations include sleeping in complete darkness, avoiding blue light-emitting devices before bedtime, and practising fasting to boost melatonin levels naturally. For older adults and those suffering from obesity, Professor Agil advises the administration of melatonin under medical supervision.

The overarching goal of these studies is to integrate strategies like melatonin administration and intermittent fasting into medical practices to address the complex challenges posed by ‘diabesity’—a confluence of diabetes and obesity—and its associated complications, such as hepatic steatosis, hypertension, and lipid disorders. The research builds on 13 years of prior studies which have consistently shown that pharmacological use of melatonin can serve as a viable strategy in treating central obesity and its related complications. Moreover, melatonin has been found to activate brown fat and enhance the conversion of subcutaneous fat to a more metabolically active form, thus promoting the formation of beige fat cells from mesenchymal stem cells in humans.

These findings not only reaffirm the potential of melatonin in treating visceral obesity but also highlight the necessity for further clinical trials to confirm its efficacy in human subjects. Encouraging results from existing human trials support the progression to more extensive studies focusing on melatonin’s role in maintaining mitochondrial homeostasis and potentially slowing or halting the progression of obesity and its complications through prolonged pharmacological use.

The research has received funding from the SAF2016-79794-R project of the Ministry of Science, Innovation and Universities and is also supported by the European Regional Development Fund (ERDF).