HEALTH NEWS

Study Title:

Melatonin and Obesity

Study Abstract

The study objective was to investigate the effects of melatonin on obesity and obesity-associated systolic hypertension and dyslipidemia in young male Zucker diabetic fatty (ZDF) rats, an experimental model of the metabolic syndrome. ZDF rats (n=30) and lean littermates (ZL) (n=30) were used. At 6wk of age, both lean and fatty animals were subdivided into three groups (n=10): naive (N), vehicle-treated (V), and melatonin-treated (M) (10mg/kg/day) for 6wk. Vehicle and melatonin were added to the drinking water. Melatonin reduced mean weight gain (51±2/100g BW) versus N-ZDF group (58±3, P<0.05) without food intake differences. M-ZDF rats showed an apparent reduction in systolic hypertension that proved not to be statistically significant, and a significant improvement in dyslipidemia, with a reduction in hypertriglyceridemia from 580±40 to 420.6±40.9mg/dL (P<0.01). Melatonin raised high-density-lipoprotein (HDL) cholesterol in ZDF (from 81.6±4.9 to 103.1±4.5mg/dL, P<0.01) and ZL rats (from 62.8±4.8 to 73.5±4.8mg/dL, P<0.05) and significantly reduced low-density-lipoprotein (LDL) cholesterol in ZDF rats from 5.20±0.4 to 4.14±0.3 mg/dL (P<0.05) but had no effect on total cholesterol levels. To our knowledge, this is the first evidence of a positive effect of melatonin on overweight and lipid pattern of obese Zucker diabetic rats, supporting the proposition that melatonin administration may ameliorate overweight and lipid metabolism in humans. Because these benefits occurred in youth, before advanced metabolic and vascular complications, melatonin might help to prevent cardiovascular disease associated with obesity and dyslipidemia.

From press release:

University of Granada researchers have shown that melatonin -- a natural hormone produced by the body -- helps in controlling weight gain, even without reducing the intake of food. Melatonin also improves blood lipid profile, as it reduces triglicerids, and also increases HDL cholesterol and reduces LDL cholesterol.

Melatonin is found in small quantities in some fruits and vegetables as mustard, Goji berries, almonds, sunflower seeds, cardamom, fennel, coriander and cherries. Thus, the intake of this kind of food might help in controlling weight gain and preventing heart diseases associated to obesity and dyslipidemia.

Trials with rats

University of Granada researchers have analyzed in young Zucker diabetic obese rats the effects of melatonin on obesity, dyslipidemia and high blood pressure associated with obesity. Melatonin was found to be beneficial for young rats that had not still developed any metabolic or heart disease. Researchers think that melatonin might help prevent heart disease associated with obesity and dyslipidemia.

Finally, authors state that if this finding is confirmed in humans, administration of melatonin and intake of food containing melatonin might be a useful tool to fight obesity and the risks associated with it.

Study Information

Agil A, Navarro-Alarcón M, Ruiz R, Abuhamadah S, El-Mir MY, Vázquez GF.
Beneficial effects of melatonin on obesity and lipid profile in young Zucker diabetic fatty rats.
J Pineal Res.
2011 March
Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, Granada, Spain.