Sunlight has kept our brains on a 24-hour schedule for hundreds of thousands of years. Here’s how.

When sunlight touches your skin or hits your eyes, your brain ups the production of serotonin, to make you feel alert. And when night falls, your brain switches to releasing melatonin, so you know it’s time to sleep. So when we don’t get enough sunlight, our biological cycles can start to break.

In this episode, we discuss:

• How Vitamin D is made, and what benefits it has for your brain health
• The evolutionary complexities of your circadian rhythm, and how it’s been thrown into chaos by modern life
• What happens to our mental health when winter shortens daylight hours
• How light therapies can help people living in cloudier climates to protect their cognitive health
• The association between not getting enough sunlight and developing neurodegenerative diseases like dementia

We’re joined by Population Health Science and Policy scientist and ‘lighting researcher’ Dr. Mariana Figueiro to discuss how light-emulating technologies can help simulate sunlight in darker spaces during gloomier times of year.

And Dr. Satchin Panda, leading expert in the field of circadian rhythm research and a founder of the Center for Circadian Biology at the University of California, to dive deep into the neurological intricacies of our 24-hour body clock.