Modern life has brought with it a constant glow of artificial light, from LED bulbs, smartphones, laptops, TVs, and other devices. While convenient, research shows that excessive exposure to light at night can disrupt sleep, affect the circadian rhythm, and increase the risk of heart disease. Experts warn that our bodies are naturally designed to rest in darkness, and prolonged exposure to artificial light can confuse this internal system.
THE SCIENCE BEHIND NIGHTTIME LIGHT EXPOSURE
The human body operates on a circadian rhythm, a natural internal clock that regulates sleep, heart rate, blood pressure, hormone levels, and other vital functions.
According to research conducted at the Flinders Health Medical Research Institute in Australia, prolonged exposure to bright artificial light at night can disrupt this rhythm. This disruption has been linked to irregular heartbeats, higher chances of coronary artery disease, heart attacks, and even stroke.
Interestingly, the harmful effects are not just due to less sleep.
The study found that even when accounting for lifestyle factors such as diet, exercise, smoking, or body weight, artificial light itself remained a significant risk factor for cardiovascular problems.
Women appear to be more vulnerable to heart disease caused by nighttime light, while younger adults are more prone to irregular heart rhythms.
According to Professor Dr. Nawaz Lashari, Chairman of the Cardiology Department at Civil Hospital Karachi, local patients with heart issues often report excessive use of mobile devices or bright lights at night. Disruption of the natural circadian rhythm can affect the eyes, brain, and heart, leading to fatigue, headaches, dark circles under the eyes, and, over time, an increased risk of heart disease.
WHY WHITE OR BLUE LIGHT IS PARTICULARLY HARMFUL
Not all light affects the body equally. White or blue-rich light, such as that from many LED bulbs, screens, or cool-white lights, is especially disruptive.
According to a review in the Journal of Pineal Research, exposure to blue or white light in the evening suppresses the production of melatonin, the hormone that signals the body it’s time to sleep.
Research published in Environmental Health and Preventive Medicine explains that special light-sensitive cells in the eyes detect blue light and send signals to the brain, effectively tricking the body into thinking it is daytime.
This suppression of melatonin delays sleep onset, reduces sleep quality, and can even last for hours after the exposure ends, according to PubMed.
THE BENEFITS OF WARM LIGHT AT NIGHT
Using warm toned lighting in the evening, such as orange, yellow, or red bulbs, offers multiple health benefits, according to research.
Warm light minimizes suppression of melatonin, allowing the body to prepare naturally for sleep, according to PubMed (2019).
It also reduces eye strain compared to bright white or blue-rich light, making it easier to relax after a long day, according to the Journal of Pineal Research (2018).
Additionally, warm light supports the circadian rhythm, helping regulate sleep wake cycles and indirectly protecting cardiovascular health by promoting restorative sleep, according to Environmental Health and Preventive Medicine (2014).
PRACTICAL TIPS TO PROTECT YOUR SLEEP AND HEART
Experts suggest several simple but effective strategies to minimize the harmful effects of nighttime light,
1. Use Dim, Warm Lighting at Night
Switch to orange, yellow, or red-toned bulbs in the evening. Warm light is less likely to suppress melatonin, according to PMC (2019).
2. Limit Screen Time Before Bed
Avoid smartphones, laptops, TVs, or tablets at least one hour before sleeping. Blue light from screens signals the brain it’s daytime, making it harder to fall asleep, according to PubMed (2010).
3. Use Blue Light Filters or Night Mode
If device use is unavoidable, enable night mode or blue light filters to reduce the short wavelength light that interferes with melatonin production.
4. Keep Your Bedroom Dark
Use blackout curtains or an eye mask to block external light from street lamps or devices. Darkness naturally signals your brain that it’s time to sleep.
5. Maintain a Consistent Sleep Schedule
Go to bed and wake up at the same time daily, even on weekends. A regular routine reinforces your circadian rhythm.
6. Dim Household Lights in the Evening
Reduce overall lighting 1–2 hours before bedtime to help your body transition naturally to night mode.
7. Avoid Bright Light During Nighttime Wake-ups
If you wake during the night, use only a dim night light to prevent your body from thinking it’s morning.
Following these simple adjustments can support melatonin production, improve sleep quality, and reduce long term risks of heart disease and metabolic problems.
CONCLUSION
While artificial lighting has become an essential part of modern life, understanding its effects on the body is crucial.
According to research and expert observations, limiting nighttime exposure to bright or blue rich light can protect your sleep and cardiovascular health. By adopting dim, warm lighting, minimizing screen use before bed, and maintaining consistent sleep habits, you can support your natural circadian rhythm and reduce the hidden risks of modern living.
FAQs
Q1: Does using my phone at night really affect my heart?
Yes. Research shows that excessive exposure to bright or blue rich light at night can disrupt the circadian rhythm, affect melatonin production, and over time increase the risk of heart disease.
Q2: Are all lights harmful at night?
No. Warm toned lights (orange, yellow, or red) are less disruptive to melatonin and sleep. Blue rich or white lights, such as LEDs and screens, have the greatest impact.
Q3: How long before bed should I stop using screens?
Experts recommend avoiding screens at least 1 hour before sleep and keeping bedroom lighting dim.
Q4: Can dimming lights really improve sleep quality?
Yes. Dim, warm lighting signals your body that its nighttime, helping melatonin levels rise naturally and supporting a healthy sleep cycle.
DISCLAIMER
This content is for educational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider for personalized recommendations regarding sleep, heart health, or medical conditions.
CALL TO ACTION
Protect your heart and sleep tonight! Switch to dim, warm lighting, limit screen time before bed, and maintain a consistent sleep schedule. Share these tips with family and friends to help them sleep better and stay heart-healthy too.
Read more: https://pharmahealths.com/calcium-supplements-dont-fix-osteoporosis/
REFERENCES
1. Flinders Health Medical Research Institute, Australia. Study on Nighttime Artificial Light and Cardiovascular Health.
2. Professor Dr. Nawaz Lashari, Civil Hospital Karachi, Cardiology Department insights.
3. Environmental Health and Preventive Medicine. Impact of evening light exposure on circadian rhythm.
4. PubMed Central. Blue light suppresses melatonin production and delays sleep onset.
5. Journal of Pineal Research. Effects of light wavelength on melatonin and circadian rhythms.
6. Healthline. Tips for reducing blue light exposure at night.
