Extending daylight could boost health, help planet

By Kate Kelland, Health and Science Correspondent Kate Kelland, Health And

Science Correspondent Fri Oct 29, 7:41 am ET

LONDON (Reuters) Putting the clocks back in winter is bad for health, wastes

energy and increases pollution, scientists say, and putting an end to the

practice in northern areas could bring major health and environmental benefits.

Countries across Europe, the United States, Canada and parts of the Middle East

mark the start of winter by ending Daylight Saving Time (DST) and putting their

clocks back by an hour -- often in late October or early November -- a move

that means it is lighter by the time most people get up to start their day.

But this also robs afternoons of an hour of daylight, and some experts argue

that in more northern regions, the energy needed to brighten this darkness, and

the limits it puts on outdoor activities are harming our health and the

environment.

Leaving clocks alone as winter approaches would allow an extra hour of daylight

in the afternoon and could boost levels of vitamin D as well as encourage

people to exercise more.

In some countries, such as Britain and Russia, politicians are being asked to

consider parliamentary bills suggesting it's time for a change.

"It must be rare to find a means of vastly improving the health and well-being

of nearly everyone in the population -- and at no cost," said Mayer Hillman of

the Policy Studies Institute in Britain, where a bill on DST is coming up for

consideration in parliament soon. "And here we have it."

Almost half of the world's population has lower than optimal levels of vitamin

D, often called the sunshine vitamin. Vitamin D deficiency is a well-known risk

factor for rickets and evidence suggests it may increase susceptibility to

autoimmune diseases.

BRIGHT IDEA?

Hillman conducted a study focused on Scotland, the northern-most part of

Britain, which found that switching to Central European Time -- to Greenwich

Mean Time plus one hour (GMT+1) in the winter and GMT+2 in the summer -- would

give most adults 300 extra hours of daylight a year.

A "lighter later" campaign in Britain has gained support from many of the

country's major sporting bodies.

Writing in the British Medical Journal on Friday, Hillman said research shows

people feel happier, more energetic and have lower sickness rates in the

longer, brighter days of summer, whereas moods and health decline during duller

days of winter.

Dr. Robert Graham of Lenox Hill Hospital in New York said leaving clocks alone

in winter should be considered to encourage people to get out more and get more

exercise.

High rates of chronic illnesses such as diabetes, heart disease and obesity are

caused in part by lack of exercise -- adults are advised to do 30 minutes

moderate or vigorous activity a day, and children at least an hour.

"As a society we are always looking for accessible, low cost, little-to-no harm

interventions," he said by telephone. "By not putting the clocks back and

increasing the number of accessible daylight hours, we may have found the

perfect one."

A study published earlier this year found that advancing clocks by an hour in

the winter would lead to energy savings of at least 0.3 percent of daily demand

in Britain.

Elizabeth Garnsey, one of the study's authors and an expert in innovative

studies at Cambridge University, said this was equivalent to saving 450,000

metric tons of CO2 during winter alone.

(Editing by Paul Casciato)