Baku, February 4 (AZERTAC). Energy saving light bulbs could result in higher breast cancer rates if used late at night, an academic has claimed, according to Daily Telegraph.

Abraham Haim, a professor of biology at Haifa University in Israel, said that the bluer light that compact flourescent lamps (CFLs) emitted closely mimiced daylight, disrupting the body`s production of the hormone melatonin more than older-style filament bulbs, which cast a yellower light.

Melatonin, thought to protect against some breast and prostate cancers, is produced and secreted by the brain`s pineal gland around the clock.

Highest secretion levels are at night but light depresses production, even if one`s eyes are shut.

A possible link between night time light exposure and breast cancer risk has been known for over a decade, since a study was published showing female shift workers were more likely to develop the disease.

Prof Haim explained that a recent study by himself and fellow colleagues had found a much stronger association than previous research between night-time bedroom light levels and breast cancer rates.

They thought one of the reasons for this stronger link could be that people had switched to using energy saving lightbulbs.

The bluer light also made people more alert and increased their body temperature and heart rate.

Prof Haim thought this was because the bluer light from eco-lightbulbs mimiced the stronger light of midday closer than filament bulbs did.

Speaking to The Daily Telegraph, he said he had subsequently removed eco-friendly lightbulbs from his house, as he thought they caused "light pollution".

He said: "Around the world the advice is to change the lights to `green` bulbs - but they are not really green. They pollute much more light."

Because people thought they were so cheap to run, they were turning on more lights at home, he explained.

He emphasised that the study did not prove that using eco-friendly light bulbs late at night or overnight resulted in higher breast cancer rates than using filament bulbs, and that it remained an unproven theory.