Huberman Lab

#### Summary Lead

Dr. Glenn Jeffrey explains how indoor lighting, especially LED exposure, affects mitochondrial health and why balancing short and long wavelength light is crucial for overall well-being.

Introducing Dr. Glenn Jeffrey and His Research

Dr. Glenn Jeffrey, a neuroscience professor at University College London, shares groundbreaking insights into how specific wavelengths of light influence mitochondrial function. His work reveals that red, near-infrared, and infrared light can improve skin, eyesight, metabolism, and even brain health by supporting cellular energy production.

The Spectrum of Light and Its Biological Impact

Light extends beyond what the human eye can see, ranging from ultraviolet (short wavelengths) to infrared (long wavelengths). Short wavelengths, like UV, can damage skin and eyes, causing sunburn and cataracts. In contrast, long wavelengths penetrate deeply, interacting with water in mitochondria to boost energy production and protect cells from damage.

Long Wavelength Light Enhances Mitochondrial Function

Jeffrey’s research shows that long wavelength light increases mitochondrial efficiency by affecting the water surrounding these organelles. This stimulation improves ATP production and encourages the synthesis of proteins involved in energy generation. The effect is systemic, influencing tissues far beyond the area directly exposed to light.

Deep Penetration of Long Wavelength Light

Long wavelength light can pass through skin, clothing, and even bone, reaching internal organs and the brain. This surprising ability allows it to support mitochondrial health throughout the body, making it a powerful tool for improving overall cellular function and longevity.

Red Light’s Role in Blood Sugar Regulation and Vision

Experiments demonstrate that shining red light on a small skin area can reduce blood glucose spikes after meals. Additionally, red light exposure improves color vision and slows retinal aging, especially in older adults. These benefits highlight the potential of targeted light therapy for metabolic and visual health.

The Hidden Dangers of LED Lighting

Modern LED lights emit a high proportion of short wavelength blue and violet light without balancing long wavelengths. This imbalance harms mitochondria, leading to metabolic issues, weight gain, and impaired behavior in animal studies. Jeffrey warns that excessive LED exposure may pose a public health risk comparable to asbestos.

Incandescent and Halogen Lights Offer a Healthier Alternative

Unlike LEDs, incandescent and halogen bulbs emit a smooth, full spectrum of light similar to natural sunlight, including beneficial long wavelengths. Using these bulbs indoors, especially in winter or windowless environments, can help restore mitochondrial function and improve well-being.

Practical Advice for Indoor Lighting and Health

To counteract the negative effects of LED lighting, Jeffrey recommends increasing exposure to natural sunlight and supplementing indoor environments with incandescent or halogen lamps. Adding plants near windows can also reflect infrared light, enhancing indoor light quality. For those on a budget, even beeswax candles provide some long wavelength light.

Light Therapy for Mitochondrial Diseases and Aging

Clinical trials suggest that red light therapy can significantly improve symptoms in children with mitochondrial diseases and slow vision loss in retinal disorders. Early intervention is key, as advanced disease stages respond less to light therapy. This research opens new avenues for non-invasive treatments targeting cellular energy.

The Urgency of Rethinking Public Lighting

Jeffrey emphasizes the need for public health awareness about lighting’s impact on biology. Architects and healthcare providers are beginning to consider lighting quality in building design, recognizing that better light environments could reduce illness, improve recovery times, and enhance quality of life.