With the Sunshine Protection Act awaiting review from the Senate, WFIU News spoke to health care professionals on the health risks posed by permanent daylight saving time: higher risk of cardiovascular events, metabolic disorders, motor vehicle accidents and fatalities among school-age children due to darkness in the morning before school starts.
The Act was passed by the House earlier this month. If signed into law it would require the country to observe daylight saving time year-round, except for states with exempt areas. Sunrise and sunset would be later in the day.
For example, the majority of Indiana is in the Eastern Time Zone; it would experience the sun rising past 9 a.m. The counties in northwest and southwest Indiana are in the central zone, which would experience the sun rising past 8 a.m.
Stephanie Stahl, medical director of Indiana University Health Indianapolis Sleep Laboratory, said the time that best aligns with the internal body clock is standard time, not daylight saving time.
One’s wake and sleep cycles are regulated by circadian rhythms, which control the secretion of hormones, Stahl said. The main factors that help regulate one’s circadian rhythm are light and darkness.
“We want bright sunlight exposure in the morning that helps turn off nighttime hormones and kick on daytime hormones, and then the opposite at nighttime. We want it to start to become dark and dimmer,” she said. “Ideally, two to three hours before our bedtime, so then our body can start to produce those factors that tell us that it's time to be ready to go to sleep.”
Daylight saving time decreases sun exposure in the morning and increases sun exposure at night. Stahl said more sunlight in the evening, prevents individuals from receiving cues their body needs to let them know it’s time to go to sleep. This leads to insufficient sleep, which causes people to be at a higher risk of obesity, diabetes, metabolic disorder, and cancer. Insufficient sleep is also associated with increased risk of cardiovascular events, such as heart attacks and strokes, high blood pressure and dementia.
“So, getting less than seven hours of sleep on a regular basis markedly increases risk of memory issues,” she said.
Sarah Honaker, associate professor of pediatrics at IU’s School of Medicine, said that one’s body doesn’t adjust to daylight savings time even after several months. That not only increases health risks but also increases deaths from suicide or overdose, increases motor vehicle accidents and increases fatalities among school-age children.
“So, we know that there are more fatalities among school-age children in the mornings from January to April, and this is likely because of going to school when it's dark out. So they are more likely to be hit and injured as pedestrians,” Honaker said. “It's also a possibility that their parents are more sleep deprived due to the misalignment between the natural rhythms and the social clock.”
Adolescents and young adults would be the most negatively impacted she said because they already have a normative circadian delay. They are already prone to going to sleep later and waking up later.
“This would be exacerbated with permanent daylight savings time because the light would be pushed later, which would further delay their circadian timing system,” she said. “And many adolescents have early school start times the next morning, and so adolescents are already heavily sleep deprived. So most adolescents in the U.S. are not getting enough sleep already, and permanent daylight savings time would almost certainly worsen this trend.”
Honaker said locations that are the furthest west in terms of their longitudinal position within a time zone, like Ind. within the Eastern Time Zone will experience more effects that are associated with insufficient sleep due to their position in the time zone.
“The health risks are real, they're well established and they're significant,” Honaker said. “And I think that has to outweigh our personal preference for a little bit more evening sunlight.”