TLDR;
This video discusses the importance of light for human health, focusing on the different types of light (UV, visible, and infrared) and their effects on the body. It covers practical ways to optimize light exposure, including getting sunlight in the morning, using SAD lamps, and being mindful of artificial light at night. The conversation also touches on the dangers of excessive sunscreen use and the benefits of incandescent bulbs over LED lights.
- Importance of sunlight for overall health, beyond just vitamin D.
- Practical ways to optimize light exposure for circadian rhythm and mood.
- Dangers of artificial light and the benefits of infrared light.
Intro [0:00]
The video introduces the concept of "scurvy of the 21st century," which refers to the lack of diverse wavelengths of light, particularly infrared, in modern indoor environments. It highlights that modern environments are often devoid of the same wavelengths of light that the sun provides, which are beneficial for cells. Incandescent bulbs are presented as superior to narrow-band LED red or infrared light therapy due to their diverse multi-wavelength light, similar to sunlight.
Why Light Is Medicine (and We’ve Been Ignoring It) [1:09]
The discussion begins with the sun as the ultimate source of light and its three types of light: ultraviolet (UV), visible, and infrared. UV light converts cholesterol derivatives in the skin into vitamin D, crucial for bone and immune health. Visible light, including colors like green and blue, affects pain perception, with light itself acting as a primary driver, zeitgeber, of the brain's clock, impacting all bodily systems. Infrared light, comprising over 50% of the sun's photons, penetrates the body deeply, upregulating energy production in mitochondria. Studies show infrared light exposure reduces recovery time in intensive care patients.
The Truth About Sunscreen Nobody Talks About [25:48]
The conversation shifts to sunscreen and its effects. Sunscreen primarily blocks ultraviolet light, which can also be achieved with clothing. Concerns are raised about the efficacy of sunscreens, with studies showing many products not meeting their labeled SPF. There's a psychological effect where sunscreen users may spend more time in the sun, increasing skin damage. The chemicals in sunscreens and their long-term effects on the body are questioned. Effective protection methods include covering up with clothing, wearing hats, and avoiding direct sunlight during peak hours.
The Morning Light Habit That Rewires Your Brain [32:53]
The discussion focuses on visible light and its interaction with photoreceptors in the eye, specifically intrinsically photosensitive retinal ganglion cells. These cells project to the suprachiasmatic nucleus (the brain's timekeeper) and the perihabenular nucleus (regulating mood). Exposure to bright light, especially in the morning, is crucial for maintaining circadian rhythm and mood. The intensity of indoor light is significantly lower than outdoor light, making it essential to go outside for adequate exposure.
How the Night Shift Wrecks Your Clock — and How to Fight Back [53:28]
The discussion addresses the challenges faced by night shift workers, whose work schedules disrupt their circadian rhythms. The best approach for night shift workers is to fully adapt to a nocturnal schedule, maintaining it even on days off. A study showed that night shift workers who restricted their eating to daytime hours experienced reduced metabolic disturbances.
The Hidden Damage of Artificial Light at Night [1:08:28]
The conversation emphasizes the importance of darkness at night for circadian health. It is recommended to minimize light exposure in the evening, especially overhead lights, and to use dim, red-shifted lights if necessary. The discussion also touches on the potential benefits of moonlight, which contains infrared light.
Why Your Mitochondria Crave Infrared Light [1:12:00]
The discussion transitions to infrared light, highlighting its importance for mitochondrial health. Infrared light penetrates the body deeply and interacts with mitochondria to enhance ATP production. The sun's photosphere and the Earth's atmosphere are uniquely suited to allow infrared light to reach the surface. Studies show that infrared light can reduce hospital stays for COVID patients and improve glucose metabolism.
What Incandescent Bulbs Get Right About Sunlight [1:38:22]
The conversation discusses incandescent bulbs as a source of broad-spectrum light, including infrared, which is beneficial for mitochondrial function. A study showed that adding a 60W incandescent bulb to an LED environment improved visual discrimination of color. However, incandescent bulbs are being phased out due to energy efficiency regulations.
How to Hit Your Ideal Daily Light Dose [1:48:28]
The discussion concludes with practical advice on optimizing light exposure. Getting outside for 15 minutes before 9:00 AM is recommended to obtain visible light for cortisol production and infrared light for mitochondrial health. The importance of awareness and diligence in maintaining a healthy light environment is emphasized.
