03/07/2026
Heart attacks rise by 24% after the spring DST clock change.
Losing an extra hour of sleep may not be the worst thing that could happen when you “spring forward” at the start of daylight-saving time. According to a study of hospital admissions across the state of Michigan, there was a 24% increase in heart attacks on the Monday following the switch to daylight saving time. In a study from Finland, researchers found that the overall rate of ischemic stroke was 8% percent higher during the first two days after a daylight-saving time transition. Other research has found that, in general, more serious heart attacks occur on Mondays than on any other day of the week, making the day after the time change even more worrisome.
Hypertension Specialist with the American Heart Association Dr Maria Delgado-Lelievre believes this uptick is the result of disruption to the body's internal clock, or its circadian rhythm.
I talk a lot about the importance of light signals for achieving optimal health and encourage everyone to get outside and capture these signals with their naked eyes every single day, but, if there is one day you really prioritize this it should be tomorrow (Sunday). Losing 1 hour of sleep causes our circadian rhythm to temporarily fall out of sync.
Why is this detrimental?
Our bodies don't run by the clock. They run on the sun. Our circadian clock, located in the brain controls the production of hormones, our metabolism, immune function, sleep, mood and much more. This clock is synchronized by sun light entering our eyes, especially morning sunlight.
Throwing this rhythm out of sync has a cascade effect on all the cells of our body and their function.
Correcting this imbalance as quickly as possible is the best way to combat the negative effects of DST.
Things you can do to help your rhythm return:
☀️Lower your exposure to artificial light after dark the night before.
☀️ Stay hydrated and get a good night's sleep (8 hours is optimal)
☀️Step outside tomorrow morning as close to sunrise as possible. Just 5-10 mins helps recalibrate your CR. It doesn't matter if it's cloudy - the full spectrum of light is still visible to your eyes.
☀️Get back outside at UVA rise - this is usually around 1 hour after sunrise, again 5-10 mins will help recalibrate. UVA rise activates a cascade of metabolic reactions, most notably clearing last night's melatonin and activating cortisol, which tells the body it's time to switch from repair mode to performance mode.
☀️Go back outside for 5-10 min around sunset. This signals the body it's time to enter rest and repair and signals the pineal gland to standby for the production of melatonin a few hours after sunset.
Artificial light and blue light like that emitted from our phones carries the same light signals as the midday sun, so excessive exposure to this keeps your CR in a perpetual state of midday - which is peak performance, preventing our cells from adequately performing their morning and nighttime functions and throwing our bodies into a state of imbalance or dis-ease.
Study citations -https://openheart.bmj.com/content/openhrt/1/1/e000019.full.pdf
https://heart.bmj.com/content/109/Suppl_3/A78
