‘Scientifically it’s not a good idea,’ says researcher whose work informed B.C.’s daylight decision

Scientists who study sleep are warning that BC’s decision to adopt permanent daylight could have a negative impact on overall health, especially the health of children.

“Scientists around the world are warning about the negative health and safety impacts of permanent daylight saving time and advocating for permanent standard time instead,” said Myriam Judah, an assistant professor and sleep researcher at Simon Fraser University.

The change means BC will transition to daylight time this weekend and will never change clocks again.

Among the critics is Jamie Zeitzer, a professor in the department of psychiatry and behavioral sciences at Stanford University, whose Research This was cited by the BC government in its news release announcing the change.

Zeitzer says it was “a little strange” to see his work used in this way.

“It’s not a good idea scientifically, and in terms of health, I don’t think it’s a good idea to make this kind of change,” he said.

what does science say

Standard time means the Sun is at its peak around noon, with daylight divided more evenly between morning and afternoon. Daylight saving time moves the clocks forward one hour, meaning less light in the morning and more light in the afternoon.

Judah said the change could disrupt our circadian clock, which controls the sleep-wake cycle.

“This circadian clock synchronizes with the sunlight’s light-dark cycle through specialized photoreceptors in the eye. And exposure to morning light is really important here,” he said.

Morning light helps determine the timing of melatonin release at the end of the day. Without it, Judah said, people may feel more alert at night and more tired during the day. He said teenagers are particularly affected because their sleep patterns change from earlier to later.

He said, sleep is also important for the brain development of children.

Communities located on the western edge of the time zone, such as Vancouver and Victoria, are particularly affected by dark winter mornings under permanent daylight. In the middle of winter, sunrise will be after 9 am due to the change in both cities.

“This means most children will go to school in the dark. Most office workers will work in the dark and won’t even get a chance to get the morning light,” Judah said.

They estimate that most British Columbians will lose an average of less than half an hour of sleep each night after the change.

The length of daylight can also contribute to “social jet lag”, when daily schedules misalign with the body’s preferred light exposure. In the short term, this may mean that people feel lethargic or lethargic. Over time, that mismatch — coupled with less sleep — can turn into other health problems.

Zeitzer said modeling by his team in the US has linked out-of-sync circadian cycles to a range of poor health outcomes.

“Basically, staying in permanent standard time — from a circadian perspective — is going to be much healthier than switching to permanent daylight time, especially when it comes to stroke and obesity,” he said.

None of the scientists interviewed by CBC said they were aware of peer-reviewed health research supporting a switch to permanent daylight saving time.

However, Zeitzer said his team’s research also suggests that eliminating the twice-a-year clock changes is better than maintaining them. He said the spring time change – but not the fall – is linked to higher rates of heart attacks and car accidents as people adjust to less sleep after moving their clocks forward an hour.

Public support, limited options

The additional evening light from permanent daylight hours will have benefits in the form of more time for outdoor activity and safe commutes, the BC Ministry of the Attorney General said in an emailed statement.

“Focusing on limited winter daylight at the end of the day better aligns with the time when most people are active, which can help reduce conflicts and improve overall well-being.”

The government cited over 90 percent support for permanent daylight saving time during a public consultation in 2019.

But British Columbians were given only two options: keep changing the clocks or switch to permanent daylight saving time. Other options – such as permanent standard time – were not considered.

“It’s not really a valid option,” Zeitzer said. “It’s like saying… am I doing a great job as a teacher or a great job as a teacher?”

The government stated that standard time was not offered as an option because none of BC’s neighboring jurisdictions were considering moving to a permanent standard.

“We wanted to ensure that any decision we made would be done in a way that would remain consistent with these jurisdictions. Thus, we did not consider moving to standard time to be a viable option.”

The ministry did not respond to questions about which scientific sources were consulted to inform the decision to choose daylight hours.

Zeitzer said there may be economic reasons why some people favor daylight saving, including longer, lighter evenings.

“People will go golfing, shopping and eating out, otherwise they wouldn’t do that if it was already dark. And frankly, if the argument is that it will make the rich get richer, I don’t think it will have a health impact,” he said.

But if there’s evidence that people who work in these places have jobs they wouldn’t otherwise have and their incomes go up, then there may be a health argument, he said.

“But they’re not really well prepared.”