London, Oct 5 (IANS): Chronic consumption of melatonine, a hormone found in animals, plants, and microbes, helps combat obesity and type-two diabetes, says a study.

"Melatonine is abundant in vegetables, spices, herbs, tea, coffee, fruit, seeds and nuts. This is one of the main reasons why these foods are healthy," said lead researcher Ahmad Agil, a professor at University of Granada in Spain.

The study involved several experiments conducted on Zucker obese rats.

In the case of obesity, mitochondria (our cells' power stations) do not work properly (homeostatic imbalance) and their programmed destruction is accelerated.

Chronic administration of melatonine in young obese rats with diabetes mellitus type-two, similar to its human equivalent, improves mitochondrial dysfunction (i.e. mitochondrial homeostatic functions) in a very efficient way, the findings showed.

Since it improves the consumption of oxygen, melatonine diminishes the levels of free-radicals stress and prevents the destruction of the mitochondrial membrane.

The researchers also pointed out that besides chronic consumption of melatonine, people should sleep in the dark to keep obesity and diabetes at bay.

Melatonine "is a natural substance present in plants, animals and humans; it works as a hormonal signal released during the night to establish circadian rhythms," Agil noted.

Excessive exposure to artificial lightning reduce endogenous melatonine levels, the researchers said.

"It is important to try to sleep in absolute darkness, to avoid interference in the generation of melatonine," Agil said.

The study appeared online in the Journal of Pineal Research.