Why is daylight savings time bad for our health?

Daylight saving time is harmful to health because it disrupts our internal body clocks, leading to desynchrony between our internal time and external time. This desynchrony can cause us to feel groggy and perform sub-optimally for a few days as our body tries to catch up. Satchin Panda explained that even a 1-hour change in alignment can result in feeling off for one or two days, and it takes about a day for our internal clock to catch up to a 1-hour time change. The negative effects are compounded when this time change disrupts feeding times, sleep patterns, and various other anticipatory activities of our body's internal clocks 1.

Andrew Huberman has also discussed how the timing of light exposure related to daylight saving time can lead to disruptions in mental health and mood. Exposure to bright light at the wrong times of the circadian cycle, specifically between 11:00 p.m. and 4:00 a.m., can cause serious disruption in the dopamine system, leading to lowered mood and difficulty in learning, among other negative effects 2. Daylight saving time exacerbates these issues by altering the timing of light exposure we receive, further disrupting our circadian rhythms.

Moreover, consistent light cues are crucial for maintaining our circadian rhythms. Daylight saving time creates inconsistent lighting conditions, which is not ideal for our biological clocks. Ensuring consistent light exposure, particularly in the morning and late afternoon, and avoiding bright light at night is beneficial for our mental and physical health, providing a vector toward wellness 3. Therefore, the abrupt shift caused by daylight saving time can lead to a range of problems due to misalignment of our internal clocks with external cues.