Anxiety, work stress, and family responsibilities may pose a threat to your sleep quality. Sleep is a biological necessity for our physical and mental well-being. Although factors that impede your sleep may be beyond your direct control, implementing simple sleeping habits can facilitate better sleep quality and can, as a result, lessen your risk of major diseases such as cardiovascular disease.
In this blog, we will navigate the world of melatonin and cortisol, often known as the “yin and yang” hormones, in regulating our daily sleep-wake cycle: the circadian rhythm. By comprehending how dysregulated cortisol and melatonin can lead to pervasive disruption to your sleep patterns, you will be empowered to embrace easy yet impactful lifestyle changes. These tailored recommendations for each critical phase of the day— the waking period (critical period 1), the active period, and the wind-down period (critical period 2)—will elevate your sleep quality and lower the likelihood of developing persistent sleep problems in the long run.
Melatonin and Cortisol: The “Yin and Yang” Hormones and Why Are They Important to Us?
Optimal Cortisol and Melatonin Levels Throughout The Day - Illustrated by Zhiyao Zhang
Melatonin and cortisol can be thought of as “yin and yang” hormones that work hand-in-hand to regulate your daily sleep-wake cycle — circadian rhythm, a biological pattern recurring every 24 hours. Changes in them can lead to a broad range of far-reaching effects on your body. Therefore, understanding what they are and how to administer them through lifestyle changes will significantly help you to improve your sleep quality.
Cortisol, often called the “wake-up” hormone, is critical in the hypothalamic-pituitary-adrenal (HPA) axis — our main stress response system. It coordinates with our brain’s perception of circadian rhythms and perceived threats to adjust our energy levels appropriately. Cortisol helps us awaken and stay energized throughout the day by increasing levels in the morning, typically ten times higher than at night in healthy individuals. Lowered levels at night can help us to ease anxiety and maintain a night of quality sleep. Disruptions in such patterns can develop several health issues.1 For example, low morning cortisol levels might lead to burnout, depression, Gastrointestinal (GI) issues, and autoimmune diseases.2 On the contrary, high evening cortisol levels may contribute to poor sleep, weight gain, and high blood pressure.
Melatonin is a clock-setting hormone that governs our circadian rhythm and resets our sleep-wake cycles based on light exposure. Increasing levels of melatonin can signal our body to relax, sleep, and recover, while decreasing levels can lead to cortisol secretion and wakefulness. Despite its pivotal role in maintaining our sleep patterns, disruptions in our circadian rhythm, followed by various symptoms, are common among people. High levels of melatonin in the morning may induce tiredness, low body temperature, dizziness, and decreased muscle tone. On the other hand, low levels of evening melatonin can contribute to difficulty falling asleep, sleep deprivation, high blood pressure, and insulin resistance.3
Tips to Help with Sleep in Three Critical Periods in Your Day:
Imbalances in the circadian rhythms due to dysregulated cortisol and melatonin may affect your energy levels and cognitive ability, leading to concerns like daytime fatigue.
Thus, to restore the balance of melatonin and cortisol and ensure your body is operating on an optimal day-night cycle, we will provide you with targeted recommendations. The recommendations will be divided into critical phases of the day: the waking period (critical period 1), the active period, and the wind-down period (critical period 2).
Critical period 1: Waking
Let's first discuss tips you can implement during the waking period to maintain proper levels of cortisol and melatonin production, understanding that what we do in the morning significantly affects the rest of the day:
1. Get bright light in the first 30 minutes of waking: By consistently exposing yourself to bright light within the first 30 minutes of waking for at least a week, you will see changes in your high morning melatonin and cortisol levels.4 Suppose natural light is unavailable due to your schedule or the season. In that case, you can use affordable artificial lights such as ring lights (with cool white color) or artists' reading tablets upon waking to help reset the circadian rhythm by offering high lux intensity.
2. Maximize morning bright light: Studies show morning bright light is the most potent regulator for melatonin and cortisol circadian rhythms.5 Embrace natural light even on cloudy or rainy mornings, as it outshines artificial light. Meanwhile, don’t forget to protect your skin with sunscreen (and leave the sunglasses off)!
3. Elevate your core temperature: Cool showers or exercise, boosting your core temperature, can benefit you in the morning.6 If you think the blast of bone-seeping cold from cold showers may be hard to embrace, you can choose to do morning exercise–an optimal alternative for you!
4. Taking a morning outdoor walk: Embarking on an early morning walk perfectly merges the first three suggestions into one healthy habit.7 We are thrilled to share that we will organize Endless Health morning walks in Austin. Please join us for one and initiate your day with us on this healthy, positive stride!
5. Eat breakfast at the same time: Some people prefer to have a morning fast. However, creating a consistent breakfast routine, ideally, an hour after waking, can serve as the second-most powerful signal for your body to cease melatonin secretion and trigger cortisol release at a set time.8 This routine will lead your body to expect food intake, regulating your circadian rhythm and enhancing overall sleep quality.
6. Caffeine in the morning can boost cortisol: Scientific research indicates that for an optimal morning cortisol surge, individuals tolerant to caffeine can consume 100+mg of caffeine, estimated 90-120 minutes after waking, effectively boosting energy and minimizing afternoon slump.9
Peak performance time: Active
7. The active period is the time of the day when your body is at peak performance. Therefore, one key tip for you during this period is not to drink coffee after 12 pm! 10
Critical period 2: Wind down
Let's discuss tips you can implement to maintain proper levels of cortisol and melatonin production during the wind-down period:
8. Implement an evening TV fast: Consider brainstorming alternative activities to watching shows or movies with your friends and family during the 2-3 hours before sleep. For example, encourage exploring alternatives such as journaling, engaging in yoga or meditation, or indulging in creative pursuits like art. If using a screen is necessary at night, it is critical that you utilize the night-shift feature available on most cell phones, laptops, and TVs. This helps reduce exposure to blue light, which can interfere with sleep quality.
9. Try an evening food/drink fast: Research supports that one effective method to reduce evening cortisol levels is to restrict ourselves to drinking only water after 8:30 PM or even earlier, depending on one's usual sleep schedule. 11 Although implementing this change may be difficult, it is one of the most extensively studied and powerful approaches for establishing a healthy circadian rhythm during the crucial wind-down period before bedtime.
10. Adjust your indoor lighting: To optimize your nighttime environment, it is suggested to minimize the use of artificial light.12 Opt for lamps positioned closer to the floor, as lower levels of light are less likely to deceive the brain into perceiving it as sunlight. Think of a warm cozy feel of Scandinavian lighting as the optimal hue to go for, and not intense lighting as found in grocery stores such as Target, as it can disrupt your circadian rhythm13. You can use free light meter apps to tell which lights are too strong and adjust accordingly.
11. Space out your evenings out: Maintaining a consistent circadian rhythm is possible with a dedicated healthy lifestyle improvement plan, but consecutive nights can disrupt your rhythm significantly, and it can become challenging to correct. Alcohol and THC consumption, particularly in large amounts, pose additional obstacles to preserving a healthy circadian rhythm.
12. Sleep at the same time each night: The key recommendation based on the timing of your samples is to aim for a consistent bedtime routine. This involves being in bed with all lights off, in a quiet and cool environment (between 66-72°F), at roughly the same time every night (with a window of around 30 minutes). If that temp feels too cold, feel free to pile on blankets for added warmth. Plan to stay in bed for around 8 hours in a dark and quiet setting without stressing too much about sleeping exactly 8 hours. The most crucial aspect is maintaining a regular sleep schedule.
Sleep Duration and ApoB Levels
Apolipoprotein B is a primary protein component of low-density lipoproteins (LDL), which are often referred to as "bad cholesterol." Elevated levels of ApoB are associated with an increased risk of cardiovascular diseases. Studies reveal intriguing insights into the relationship between sleep duration and ApoB levels.
Short Sleep Duration and Elevated ApoB: Research has shown that short sleep duration, particularly less than 7 hours per night, is associated with significantly increased odds of elevated ApoB levels. For instance, among females, short sleep duration was linked with a 1.75-fold increase in the odds of having elevated ApoB levels compared to those with 7–8 hours of sleep.14
Long Sleep Duration and ApoB: Conversely, long sleep duration, defined as exceeding 9 hours per night, showed a tendency (though not statistically significant) towards decreased risk of elevated ApoB levels. The odds ratio for elevated ApoB in this group was 0.86, suggesting a potential protective effect of extended sleep duration on ApoB levels.14, 15
What’s Next?
At Endless Health, we know that heart health is the secret to a longer life and that adopting actionable steps, such as optimizing your sleep-wake cycles, empowers you to obtain a heart-healthy future. Therefore, to improve your lifestyle using the data for the essential hormones—cortisol and melatonin—that serve a critical role in wake and rest, we highly recommend scheduling a session with an Endless Health professional. Together, we will work out a customized, data-driven, and trackable lifestyle improvement plan to build new habits to protect your heart and achieve an ideal health outcome.
References
1. Pulopulos, M. M., Hidalgo, V., Puig-Perez, S., Montoliu, T. & Salvador, A. Relationship between Cortisol Changes during the Night and Subjective and Objective Sleep Quality in Healthy Older People. Int. J. Environ. Res. Public. Health 17, 1264 (2020).
2. Adam, E. K. et al. Diurnal Cortisol Slopes and Mental and Physical Health Outcomes:A Systematic Review and Meta-analysis. Psychoneuroendocrinology 83, 25–41 (2017).
3. Circadian rhythms: a regulator of gastrointestinal health and dysfunction - PMC. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6533073/.
4. Petrowski, K., Schmalbach, B., Niedling, M. & Stalder, T. The effects of post-awakening light exposure on the cortisol awakening response in healthy male individuals. Psychoneuroendocrinology 108, 28–34 (2019).
5. Blume, C., Garbazza, C. & Spitschan, M. Effects of light on human circadian rhythms, sleep and mood. Somnologie 23, 147–156 (2019).
6. Espeland, D., de Weerd, L. & Mercer, J. B. Health effects of voluntary exposure to cold water – a continuing subject of debate. Int. J. Circumpolar Health 81, 2111789.
7. Koselka, E. P. D. et al. Walking Green: Developing an Evidence Base for Nature Prescriptions. Int. J. Environ. Res. Public. Health 16, 4338 (2019).
8. Spence, C. Breakfast: The most important meal of the day? Int. J. Gastron. Food Sci. 8, 1–6 (2017).
9. Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels - PMC. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2257922/.
10. Drake, C., Roehrs, T., Shambroom, J. & Roth, T. Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. J. Clin. Sleep Med. JCSM Off. Publ. Am. Acad. Sleep Med. 9, 1195–1200 (2013).
11. Chawla, S., Beretoulis, S., Deere, A. & Radenkovic, D. The Window Matters: A Systematic Review of Time Restricted Eating Strategies in Relation to Cortisol and Melatonin Secretion. Nutrients 13, 2525 (2021).
12. Liu, Y., Yu, C., Wang, K., Kwan, M.-P. & Tse, L. A. Linking Artificial Light at Night with Human Health via a Multi-Component Framework: A Systematic Evidence Map. Environments 10, 39 (2023).
13. Optimized office lighting advances melatonin phase and peripheral heat loss prior bedtime | Scientific Reports. https://www.nature.com/articles/s41598-022-07522-8.
14. Ren, H., Liu, Z., Zhou, X. & Yuan, G. Association of sleep duration with apolipoproteins and the apolipoprotein B/A1 ratio: the China health and nutrition survey. Nutr. Metab. 15, 1 (2018)
15. Ren, H., Zhang, L., Liu, Z., Zhou, X. & Yuan, G. Sleep duration and apolipoprotein B in metabolically healthy and unhealthy overweight/obese phenotypes: a cross-sectional study in Chinese adults. BMJ Open 9, e023817 (2019)
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