Daylight saving can have negative health effects, including heart attacks and loss of sleep, according to a co-authored study in The Conversation. The problematic effects result from the annual ritual of moving from standard to daylight saving time each March, and the country remains on daylight saving time for eight months. The American Medical Association has urged the adoption of permanent standard time, and 31% of US states have introduced legislation to this effect. The study claimed that natural light is best approximated by standard time, as exposure to extended evening light during daylight saving time has an impact on the release of the hormone melatonin, which causes sleep deprivation.
Mexico and the US state of Arizona have already introduced permanent standard time, citing benefits to health, productivity and energy savings. Research indicates that geographical location can make a difference: western-edge inhabitants who enjoy light later in the morning and evening have higher rates of chronic illnesses, while an absence in western-edge light may cause sleep deprivation. The World Wars facilitated year-round daylight saving time attempts, while an energy crisis in the 1970s boosted adoption. The study concludes that while crime rates can drop with more light at the end of the day, the health risks outweigh the benefits.