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As clocks fall back today, how does this time change impact health?

Although many people are eagerly anticipating an extra hour of slumber, it’s important to recognize the potential severe health repercussions associated with the upcoming time change. 

The end of this daylight savings time cycle will occur in the U.S. at 2 am on Sunday, November 5, as the clocks retreat by one hour, causing the 60-minute span from 1 am to 2 am to repeat itself.

For nocturnal revelers, this may seem like a boon, but it’s crucial to be aware of the associated health risks. What are the implications of this time alteration on your well-being, and are there steps you can take to mitigate these dangers? 

Strokes and time change

Professor Russell Foster, a leading circadian rhythm expert from the University of Oxford, elucidates the significance of our body clocks. These internal timers orchestrate everything from our mental clarity and digestive readiness to our muscle peak performance, all based on the 24-hour light and dark cycle.

Sunlight prompts our brain to generate signals that keep us awake and active during the day, while at night, our system, comparable to a clock’s intricate workings, stimulates melatonin production to encourage sleep. This circadian rhythm also plays a pivotal role in regulating our metabolism, body temperature, and hormone levels.

Heightened blood pressure 

However, the annual time change and clock adjustment disrupts these crucial processes, leading to sleep pattern disturbances. Professor Foster warns that a blend of sleep deprivation and circadian rhythm disruption could precipitate a stroke, with heightened blood pressure being a potential catalyst. 

This elevated blood pressure can lead to blood clot formation, obstructing blood flow to the brain, and resulting in cell death. This process manifests in classic stroke symptoms like slurred speech and one-sided body weakness.

“We have this clock, and it is fine-tuning every aspect of our physiology and behavior to the 24-hour light and dark cycle. We see increased blood pressure ranking up. For example, between 6 am and 12 noon, there is a 50 percent greater chance of having a stroke anyway. If you are being forced to get out of bed even earlier you are putting more stress on the system, which means you are less adapted to cope,” Foster explained.

Additional strain

He further added that while most individuals with a robust metabolism can handle this transition, those at heightened risk may find the daylight savings time shift placing additional strains on their biology, increasing their susceptibility to illnesses. 

A 2016 study corroborates this, revealing an eight percent surge in stroke hospital admissions within the two days following a clock change, with individuals over 65 being at an increased risk.

Heart attacks and time change

Dr. John O’Neill, a circadian rhythms specialist from the Medical Research Council Laboratory of Molecular Biology in Cambridge, has drawn parallels between clock changes and the stress associated with heart attacks. While emphasizing that these changes have a minor overall impact on health, akin to jet lag, he highlighted the chronic disruption potential in shift work, equating its health risks to cigarette smoking.

“If you fly to the states, you have a few days of jet lag where you are more vulnerable to more adverse health events, but not that much more at risk. That is what we see when you shift the clocks by an hour, it is just like getting an hour’s jet lag. It is really such a modest challenge to your circadian system that the vast majority of people deal with it absolutely fine. But because it is happening at the level of the population, you can see a slight increase in the frequency of heart attacks,” he explained.

A study led by the University of Colorado and another one from the University of Michigan lend weight to this assertion, revealing a 24 percent variation in heart attack occurrences in connection to daylight savings time changes.

Depression and mental health

The disruption to sleep patterns resulting from the clock change also has the potential to adversely impact mental health.

Studies published in The Lancet Psychiatry and the Journal of Sleep Research link disrupted circadian rhythms to conditions like depression and psychiatric disorders, and highlight the negative mood implications of sleep deprivation.

Alzheimer’s Disease

Professor Foster touches upon the exacerbation of Alzheimer’s symptoms with clock changes in his book Life Time, noting a worsening of ‘sundowning’ symptoms, characterized by confusion and anxiety, during these transitions. The Alzheimer’s Society attributes these symptoms to various factors, including disrupted body clocks.

Seasonal affective disorder (SAD)

The onset of darker evenings with the clock change can also contribute to ‘winter depression’ or Seasonal Affective Disorder (SAD). Reports from the Cleveland Clinic estimate that five percent of individuals may experience clinical SAD, while 10-20 percent of US adults may face some form of winter blues. This condition tends to be more prevalent in women, younger individuals, and those already grappling with mood-related illnesses.

Car accidents and time change

Researchers from Zurich have identified a correlation between the extra hour of sleep gained from the autumn clock change and an uptick in car crashes, attributed to drivers adjusting to darker evenings. Analysis of claims data from 2018 to 2020 revealed a notable increase in accidents occurring between 4 pm and 7 pm in November, post-clock change.

In summary, while the prospect of an additional hour of sleep may be appealing to many, it is imperative to acknowledge and understand the potential health risks associated with the upcoming clock change. Being aware and taking preventive measures can contribute to mitigating these risks, ensuring a smoother transition to the new time.

More about daylight savings time

Daylight Saving Time (DST) originated as a concept proposed by Benjamin Franklin in 1784, but it wasn’t widely implemented until World War I. Countries adopted DST to conserve energy by making better use of daylight during the warmer months.

The idea was simple: shift the clocks forward in spring to move an hour of daylight from the morning to the evening, thus reducing the need for artificial lighting and saving fuel for the war effort.

How daylight saving time works

Each year, DST begins on the second Sunday in March when people set their clocks forward by one hour. This shift pushes sunset to a later time, effectively extending the evening daylight hours.

As the seasons change and autumn approaches, clocks “fall back” on the first Sunday in November, returning to standard time. This not only grants an extra hour of sleep but also aligns waking hours more closely with the available daylight during the shorter days of the late autumn and winter months.

Benefits of the time change

Advocates of DST argue that it offers several benefits. It encourages outdoor activity in the evening, which can improve physical health and wellbeing. There is also a potential reduction in energy consumption, as longer daylight reduces the need for artificial lighting and can also decrease heating demands. Additionally, some studies suggest that DST may reduce traffic accidents, as more travel occurs during daylight.

The time change debate

Despite its benefits, Daylight Saving Time is not without controversy. Critics argue that the energy savings are minimal and that the time shift can cause disruptions to sleep patterns, leading to decreased productivity and health issues. Furthermore, there is evidence that the risk of heart attacks and workplace accidents spikes immediately after the spring transition. This has prompted some regions to consider abolishing DST altogether.

The future of Daylight Saving Time

As our understanding of circadian rhythms and the impact of DST on health and safety evolves, so too does the debate on its efficacy and relevance. Some jurisdictions have already done away with the practice. Others are actively considering permanent standard time or permanent daylight saving time.

In summary, Daylight Saving Time remains a practice rooted in historical efforts to conserve energy. While it brings longer evening daylight, which many enjoy, it also faces growing scrutiny due to its potential health impacts and questionable benefits.

The future of DST may well depend on the outcomes of ongoing research and the will of the public, as they weigh the pros and cons of this century-old tradition.

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