Join me for the 2026 light challenge☀️

Today’s newsletter features a challenge I’m personally taking on after my super fascinating conversation with sunlight and circadian biology health enthusiast Jonathan Jarecki.

If you tuned into that episode, you know just how critical sunlight is for longevity and chronic disease prevention. If you didn’t, I highly recommend doing so—there were so many fascinating takeaways. Here are some highlights: 

• Long-term data suggest that avoiding sunlight may carry real risks.
  In a 20-year Swedish study of 29,518 women, sun-avoiders had about twice the rate of death from all causes compared to women who spent more time in the sun.
  

• Light exposure can speed up healing.
  In controlled research, daily exposure to a specific light therapy called photobiomodulation (PBMT) reduced ICU length of stay, boosted muscle strength and mobility, and enhanced overall physical function compared with sham treatment, suggesting that light‑based therapy may help the body heal and perform better beyond traditional care.
  

• Sunlight exposure can reduce blood glucose in just 10 minutes.
  In a small 7‑day intervention study of adults over age 40, researchers found that 10 minutes of daily morning sunlight significantly reduced blood sugar levels. 

Alright, so you get the idea. The fear-mongering around sunlight exposure might be more harmful than it is helpful. In fact, safe sun exposure could be a critical part of our healthspan and lifespan. 

So today, I invite you to join me for the 2026 Light Challenge, started by Jonathan Jarecki. 

Here’s how to do it:

2026 Light Challenge

There are two versions: one for those who are limited on time and one for anyone looking to take their light exposure to the next level. 

Beginner:

1. Get 10-30 minutes of unfiltered morning sunlight within the first hour of waking up.

2. Take your lunch break outdoors.

3. Get 10-30 minutes of unfiltered evening sunlight.

4. Dim the lights at night and/or wear blue light-blocking glasses.

Bonus tip: Night shift + color filters on iPhone: These are features that shift your screen's colors to reduce blue light at night.  Here’s a tutorial on how to do that.

Advanced Light Challenge

1. Watch the sunrise 3-5 times a week

2. Sun-bathe midday 3-5 times a week

   1. Start small, with gradual exposure. I’ve been taking a midday walk daily as part of my sun exposure.

3. Eliminate overhead lights at night and use dim incandescent light bulbs (if you can).

That’s it! A super simple hack that could have major benefits. 

I'll see you next week,

Dhru Purohit

P.S. As you know, I’m a huge fan of increasing fiber and plant foods to support the gut microbiome, so I couldn’t be more excited for my friend Dr. Will Bulsiewicz, who just wrote a book all about this and fighting inflammation. Check out Dr. Bulsiewicz’s book here.

The information in this newsletter is for educational purposes only and should not be construed as medical advice; please consult a qualified healthcare professional before making any health-related decisions.