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Whether you love or hate it, the one-hour time shift of daylight saving time is a fact of life twice a year almost everywhere in the United States. These biannual time changes increase the available daylight during the evening in the spring when we “spring forward.” When we “fall back” in the fall, we gain morning daylight. It seems sensible in some ways. But have you ever considered the impact of daylight saving time on your health, particularly if you have hypothyroidism?
In this article, we’ll look at the health implications of daylight saving time, the effects of these one-hour time changes on people with hypothyroidism, and how to minimize the effects.
First, let’s recap. Daylight saving time is the practice of advancing the clocks by one hour during the spring to extend evening daylight. This system is typically implemented in countries with a significant change in daylight hours between winter and summer. Moving the clocks forward allows people to enjoy longer evenings with more daylight, allowing for outdoor activities. The clocks are usually set forward in the spring and set back in the fall, returning to standard time. Not all countries or regions observe daylight saving time, as its benefits and drawbacks continue to be debated.
The most common critique of daylight savings time is that it has adverse health effects due to the impact on the body’s circadian clock. In fact, doctors and researchers from the Sleep Research Society are advocating for the elimination of daylight saving time entirely. According to Dr. Beth Malow, author of the position statement and director of the Vanderbilt University Medical Center Sleep Division, “From a health standpoint, the bulk of evidence supports abolishing our current spring transition to daylight saving time and adopting permanent standard time. Daylight saving time is associated with increased risks of sleep loss, circadian misalignment, and adverse health consequences.
The circadian clock is your body’s internal clock, regulating the timing of various physiological and behavioral processes. It is essentially a biological clock that helps to synchronize functions with your external environment, particularly the 24-hour day-night cycle. The circadian clock is present in nearly all living beings and consists of thousands of neurons. It’s located in the brain and primarily determined by light exposure. Circadian rhythm describes the physical, mental, and behavioral changes that follow the 24-hour circadian clock, including:
- Alertness or sleepiness
- Sleep/wake cycles
- Body temperature
- Hormone activity and production
- Physical energy
- Eating and drinking behavior
- Immune system activity
Circadian rhythms are affected by several factors, including light and dark, hormones, body temperature, metabolism, work hours, physical activity, stress and anxiety, and additional habits or lifestyle choices.
Specifically, research has shown that the time changes during daylight saving time or when you travel can disrupt your circadian clock.
One of the most common effects of a one-hour time change is sleep disruption because the body must quickly adjust from waking up in sunlight to waking in darkness and vice versa.
The impact is quite significant. According to the Sleep Foundation, the average person receives 40 minutes less sleep on the Monday after “Springing Forward” compared to other nights of the year. And according to the American Academy of Sleep Medicine, it’s estimated that people in the U.S. lose about 19 minutes of sleep per day due to daylight saving time, which can increase the risk of obesity, diabetes, and heart disease.
After time changes, you may experience:
- Shortened sleep duration (usually by an hour or more)
- Poorer quality sleep
In addition to sleep disruption, the time change can also affect our mood and mental health. The sudden shift in daylight hours can disrupt our body’s natural production of melatonin, the hormone that regulates sleep and wakefulness. This disruption can lead to lethargy, lack of motivation, irritability, grumpiness, and even depression. Seasonal Affective Disorder (SAD), a mood disorder related to the changing seasons, can become more pronounced in those of you who are already susceptible to these mood changes.
The time change can also impact physical health. In addition to feeling more tired than usual, you may experience more body and muscle aches. Studies have also shown an increased risk of heart attacks and strokes in the days following the springtime change, possibly due to the disruption in sleep patterns and the associated stress on the body.
The time change can also disrupt your eating patterns and digestion, contributing to metabolic imbalances.
However, it’s not all negative. The one-hour time change in the spring can have some positive effects on our health. Longer daylight hours can lead to increased exposure to natural light, which has been shown to improve mood, increase vitamin D production, and enhance productivity. The extra hour of daylight can also encourage individuals to engage in outdoor activities and exercise, which has numerous benefits for physical and mental well-being.
Hypothyroidism is a condition where your thyroid gland does not produce enough thyroid hormone, leading to a slow metabolism and various symptoms. The thyroid gland is sensitive to changes in daylight, as it helps regulate our sleep-wake cycle and circadian rhythm. Therefore, any disruption to this cycle, such as the time changes involved in daylight saving time or travel, can significantly impact thyroid function and the symptoms experienced by individuals with hypothyroidism.
Your body produces thyroid-stimulating hormone (TSH) in a daily rhythm. This means TSH levels aren’t the same level throughout the day. TSH levels correspond to your body’s need for energy, and all metabolic processes, and TSH production is lower during a night’s sleep. An artificial disturbance in the daily circadian rhythm—like daylight saving time—can disrupt the cycle of thyroid hormone production. As a result, it may take longer for someone with hypothyroidism to adjust to the time change than for people with normal thyroid function.
While many people find themselves slightly groggy or disoriented for a day or two after a time change, those with hypothyroidism can experience far more severe symptoms, especially fatigue. Even with proper treatment, those with hypothyroidism often struggle with low energy levels and can find it difficult to wake up in the morning. Studies have also found that people with hypothyroidism may already experience sleep problems, such as more prolonged sleep onset and shorter sleep duration during the night. Therefore, the one-hour time change of daylight saving time may disrupt the body’s internal clock, leading to more sleep problems, additional fatigue, feelings of sluggishness, low mood, and other symptoms for people with an underactive thyroid.
When it’s time for a time change, what can you do to help minimize the impact on your health and energy levels? Here are some tips.
- Adjust your bedtime gradually: A few days before the time change, go to bed 10–20 minutes earlier or later than your usual bedtime each day. Slowly try to adjust your other daily activities—such as meal times and exercise—throughout the week prior.
- Sleep extra beforehand: Try to get at least 7 hours of sleep – and more if possible – in the days before the time change. This can help your body maintain optimal daily functioning—avoiding problems with memory and focus.
- Avoid light exposure at bedtime: Exposure to light suppresses the natural secretion of melatonin and disrupts restful sleep, so avoid electronic devices, screens, and artificial light before bedtime.
- Take advantage of natural light: Exposure to natural light can help regulate your sleep-wake cycle and reset your circadian rhythm. Try to spend time outside during daylight hours, especially in the morning. If this is impossible due to work or other commitments, consider investing in a light therapy lamp that mimics natural sunlight.
- Maintain a healthy diet: Eating a balanced diet with enough fiber, fruit, and vegetables may help with sleep quality. Avoiding eating a few hours before bedtime, limiting heavy foods, and reducing caffeinated beverages can help prevent sleep disturbances.
- Be physically active: Physical activity of varying intensity and duration is associated with better overall sleep quality. If possible, try being physically active outdoors.
- Consider relaxation techniques: Relaxation techniques such as deep breathing, meditation, or yoga can help reduce stress and promote relaxation, making it easier to fall asleep and adjust to the time change.
- Avoid naps: Resisting the urge to nap can help you feel more tired at bedtime and promote better sleep.
- Be patient with yourself: It’s important to remember that adjusting to daylight saving time can take time, especially for those with hypothyroidism. Be patient with yourself and allow your body the time it needs to adapt.
Melatonin is an additional way to help adjust to daylight saving time. Melatonin is a hormone naturally produced by the body’s pineal gland, located in the brain. It plays a crucial role in regulating the circadian clock, your sleep-wake cycles, and promoting a healthy sleep pattern.
Melatonin levels typically increase in the evening when it gets dark, signaling to the body that it is time to sleep. This hormone helps to regulate the body’s internal clock and is often used as a supplement to treat sleep disorders such as insomnia or jet lag. It is available in synthetic form as an over-the-counter medication and is generally considered safe when taken as directed.
Here are some recommendations on how to use melatonin during the time changes.
During the fall daylight saving time change, using melatonin can be beneficial in adjusting to the new sleep schedule. To use melatonin during this time change, it is recommended to take it about 4 to 5 hours before your desired bedtime. This will help signal your body to prepare for sleep at the appropriate time, even if the external daylight hours have shifted.
During the spring daylight saving time change, using melatonin for several days before the time change can help adjust your sleep schedule and ease the transition. Taking melatonin supplements 4 to 5 hours before your new, post-time change bedtime for several days can help reset your internal clock and signal your body that it’s time to sleep earlier.
Take the first step toward better health and consider becoming a Paloma member. Paloma Health is a medical practice specifically designed to help people with hypothyroidism. Our expert doctors can diagnose your condition during convenient virtual visits, create a personalized treatment plan, and prescribe your medication. Our thyroid-savvy nutritionists and health coaches can also guide you through the necessary lifestyle changes for optimal health. Paloma’s comprehensive approach to hypothyroidism care will address the root causes of your symptoms and provide you with the tools and support you need to manage your condition effectively.
Vedrana Högqvist Tabor, Ph.D., contributed to this article.