Colour may ‘set’ your body’s internal clock

Colour may ‘set’ your body’s internal clock
AS WELL AS providing the perfect backdrop for a romantic meal or holiday snap, the stunning colours of sunset may be a signal for our bodies to reset our internal ‘clocks’. It’s been known for a long time that light plays a key role in governing the circadian rhythm - the 24-hour cycle that affects everything from sleep patterns to appetite. Now, a team at the University of Manchester has discovered that changes in the colour of light can ‘set’ the internal clocks of mice, a finding they think will also prove true in humans.

“This is the first time that we’ve been able to test the theory that colour affects the body clock in any mammal. It’s always been very hard to separate the change in colour from the change in brightness,
but using new experimental tools we were successful,” said lead researcher Tim Brown. “What’s exciting about our research is that the same findings can be applied to humans. So in theory, colour
could be used to manipulate our clock, which could be useful for shift workers or travellers wanting to minimise jet lag.”

Besides the changes in light intensity that occur as the Sun rises and sets, twilight is bluer than regular daylight. The team created an artificial sky that mimicked the daily changes in colour and brightness and exposed the mice to their model. By recording activity in an area of the mice’s brains called the suprachiasmatic nucleus, or SCN, the researchers found that many of the neurones were more sensitive to changes in colour between blue and yellow, than to changes in brightness alone.