By Virginia Gurley, MD, MPH
MB (Marc Braman, MD, MPH):
Our topic this session is “Sleep, Light and Staying Young.” Thank you for sharing your expertise and the latest science with us Dr. Gurley.
VG (Virginia Gurley, MD, MPH):
Thank you for inviting me to be with you today, Dr. Braman.
MB:
In earlier sessions we’ve talked about how not getting enough light during the day and too much light at night disrupts sleep. And we’ve talked about how not enough sleep may cause or worsen many different diseases. How is it that light and sleep have such powerful effects on our health?
VG:
Well, we’ve also talked about how light is the most powerful controller of the many clocks in our bodies that keep everything working smoothly and in a coordinated way – and that’s called the circadian clock system – and it turns out that keeping these clocks working together smoothly is key to keeping our cells and body young.
MB:
So quality sleep and light at the right time is being shown to help us stay healthy and younger longer at the cellular level?
VG:
Yes, more and more research is finding that when the circadian system is out of sync, cells are not able to do very basic and important work that keeps cells and the body young.
MB:
Like what kind of cellular work are we talking about?
VG:
One kind of work that depends on the circadian system is cell repair. When the circadian system is not working well, genes, also called DNA, are not repaired as well. In addition, the proteins that are made from genes are not produced at the levels needed for optimal health, and cells are not as able to handle toxins.
MB:
DNA repair – very important, cellular functional protein production – very important, toxin processing – very important. That would be plenty, but is there anything else happening at the cellular level?
VG:
Yes, to stay young, our cells need to replace themselves, and doing that depends on cell replication and on a healthy population of immature cells called stem cells. When the circadian system is not working well, the number of times a cell can divide into two new cells, that is, replicate, and the number of stem cells that can become active as new cells, are both reduced.
MB:
Ok, obviously, making new cells is critical to long life and health. The circadian system seems to affect our cells in so many ways.
VG:
Indeed, and there is yet another kind of work controlled by the circadian system that keeps cells healthy and young, and that is how well cells use nutrients and produce energy. There is growing research evidence that when the circadian system is not working well, cells do not take in nutrients as effectively, and even when the nutrients are present, mitochondria, which are the powerhouses in our cells, are not as able to turn nutrients into energy. And as we all as know, feeling young depends on having enough energy to live your life.
MB:
Wow! Sleep: the anti-aging wonder and all-purpose health potion that actually works. We can use sleep and light as medicine to stay healthy and young as long as possible.
Thank you, Dr. Gurley.
VG:
Thank you, Dr. Braman.
Timing to perfection: the biology of central and peripheral circadian clocks. Albrecht U. Neuron. 2012 Apr 26;74(2):246-60. doi: 10.1016/j.neuron.2012.04.006. Review.
Impact of the circadian clock on the aging process. Fonseca Costa SS, Ripperger JA. Front Neurol. 2015 Mar 6;6:43. doi: 10.3389/fneur.2015.00043. Review.
