The Power of an Enriched Environment

In my leptin series a few weeks ago, I hashed out how dietary choices direct leptin levels – as well as leptin sensitivity and leptin resistance. But there’s more to leptin processing than just the food we eat (or don’t eat). As it so happens, the environment in which we live – and the good or bad “stress” we experience in it – can have an overriding impact on leptin production. Researchers at Ohio State University injected a group of mice with cancer cells and followed their progress after dividing them into two groups. One lived in a larger and “enriched” community environment with various toys, hiding areas and exercise wheels. The other group lived in groups a quarter of the size in standard lab cages. What the scientists found might leave you scrutinizing your living quarters – or at least your social calendar.

The mice that lived in the enriched environment showed “reduced tumor growth and increased remission.” In fact, the tumors in the “enriched” mice were half the size of the standard cage group after only three weeks in the stimulating environment. After six weeks, the tumors of the “enriched” mice were one fifth the size. Furthermore, the researchers could see no tumors at all in a fifth of the enriched environment group at the end of those six weeks.

The enriched environment, the researchers discovered, “upregulated” the BDNF gene (hypothalamic brain-derived neurotrophic factor), which helps regulate appetite and energy. Mice raised in standard cages didn’t show as much BDNF activity as their enriched environment counterparts. The researchers then found that the “enriched” mice also showed “downregulation of leptin production”. The enriched environment, they determined through further testing, activated the BDNF/leptin axis, which then resulted in tumor regression for the enriched mice. When the researchers studied a third group of mice that couldn’t naturally produce leptin and then administered leptin to the group, their tumors grew substantially larger than a control group given saline.

But wait, there’s more. It’s a lesson crucial for living the healthiest Primal life possible. The physical activity of the mice in the enriched environment wasn’t what made the difference. In fact, when the control mice were allowed to run in a wheel, their corticosterone levels (stress hormone) dropped below the consistently higher levels seen in the enriched environment mice. The researchers attribute the discrepancy to “good stress” – the healthy challenge – of enhanced social interaction and intellectual stimulation in the enriched environment as opposed to the pure physical exercise allowed to the controls.

That’s right: it appears that the good stress of positive social and intellectual challenge can inhibit leptin production and associated cancer growth. You can tick off all the more “concrete” tasks of a healthy lifestyle (e.g. diet, exercise), but in the end you need to have a life too – with some constructive, character-building stress.

So often, we get overwhelmed by the responsibilities of our lives. We attack the day with task-orientation and then lament feeling bogged down by the succession of endless chores. Although few of us can completely clear our slates for the week, eventually, the to-do list can morph in an ongoing attitude. We feel overrun by “bad stress.” Yet, maybe it’s more a question of balance. We put off meaningful investment in ourselves as well as our relationships and family time. We tell ourselves we can live off reserves for now – the memories of previous experiences, the benefits of old adventures – while we meet other, more pressing obligations. I dare say that our psychological selves run down just as our physical selves do. Reserves don’t last indefinitely. The spirit, as well as the body, needs continual sustenance.

It’s worth asking, how enriched is your environment right now? Do you do a job or volunteer work that’s fulfilling and/or pleasantly challenging? Are you engaged in hobbies that call on your creativity? Do you take in events or activities that move you in some way – whether it’s a ruckus-rousing football game or a suspenseful book? Do you go the extra mile in your relationships and family to make some fun and adventure? When was the last time you felt like you’d really learned something? Grown from something? Cultivating genuine happiness isn’t a selfish endeavor. Investing in your personal development – even in the midst of a busy, responsibility-filled life – isn’t an egotistical indulgence. If we can feed the mind (remember law #10!) and spirit, we bring more – more energy, more inspiration, more motivation – to the daily tasks of life. Greeting them in a renewed, even changed frame of mind, we might see them differently. Good stress helps us balance out and even diffuse the bad stress of life. We’re happier – and healthier – as a result.

On that note, Grokkers, go forth, and relish your weekend! Grab it with both hands and run like mad. Make a memorable experience –and maybe even a great story – out of it. Does this have you thinking – stirring – planning? Share the love in our comment section before you bust out, and thanks for reading today.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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41 thoughts on “The Power of an Enriched Environment”

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  1. Awesome post! Just yesterday I was talking with the Bo and saying we need to get a primal social group started down here in SoCal. Maybe monthly BBQs/hikes/etc? I definitely need more social interaction in my life. I get too focused on my work/school that I forget how happy I am with good friends.

    1. Hello, Athena,

      I have plans to help organize this sort of thing. Think “Primal Tribes” getting together to perform MDA workouts. I won’t say much more except to say stay tuned for PBF (Primal Blueprint Fitness) and local Primal clubs!

      Grok on!

      1. Mark, this is too awesome. “Primal Tribes”…. I LOVE it! I would absolutely LOVE being the organizer for the one in West michigan. I have been wanting too but I am not sure where to start. I don’t know many primal folks here in West Michigan. A few, but not many. I know that number is growing however.

      2. Awesome! I would be willing to help in any way here in Santa Cruz CA!

        1. Ely, Primal Toad, Ulfr,

          The Primal Tribe concept is in an early development stage, but when it’s out maybe you and others can be early Tribe Leaders. Stay tuned!

        1. If you’re looking for a way to start tribes without fighting through all of the hassles of online social management, maybe consider

          When I lived in Baltimore I was part of a group called Charm City Social Club that started out with 30 people and I’m pretty sure they’re closing in on (or have surpassed) 4 digit membership in less than 2 years. All they do is go out for drinks, karaoke, wine festivals, international food, drive-in movies, kick-ball leagues and just a random slew of activities. They’re tied in quite nicely with the Maryland Outdoor Club, so there are always plenty of hiking, tubing, river cleanup type activities to cross-partake in.

          I loved that time in my life and the enthusiasm of the people I was able to connect with during those enriching activities. I’d love to see something like that with a primal focus. Amazing idea, tribes! 😀

        2. Awesome. I’m in San Diego, too, and just getting into the Primal thing. This sounds like a great idea.

  2. hilarious to read this just now. Not only do we have this weekend packed full with fun & engaging activities, but we just booked our first-ever trip to Scotland. If that’s not good stress, then there’s no such thing. 😀

    1. Scotland is friggin Awesome! don’t miss the highlands & if possible, some highland games (what could be more primal than tossin the caber?)
      Also, you can see the Castle Arrggghhhh (from Monty Python & the Search for the Holy Grail)
      eating smoked salmon in view of Loch Ness… got room for one more?

      1. oh yes! The Highlands are first on our list, but I didn’t know about the Castle Arrgghhh! 😀

        1. I was in Scotland two years ago! Castle Arrrggghh! It called Doune Castle, which means Castle Castle. Awesome, huh?

    2. Scotland is the best place to be 🙂 I’m not far from Inverness you can connect with me through my blog if you are going to be anywhere nearby!

  3. Jon Gabriel talks about the differences between positive and negative stress in his book. It was very enlightening (as was this post). But although I do believe there are positive “stressors” that can be beneficial, it’s important to keep in mind that’s no excuse to bombard your to-do list with these activities. Downtime is still a key to good health. No need to dart around frantically trying to encounter positive stressors. Take a break now and then, too.

  4. I agree with getting bogged down. We live in a 90 year old house (anyone seen Money Pit?) that constantly resists any repairs or upgrades. It’s really easy to get in the habit/rut of having your nose to the grindstone to get things accomplished and forgetting to have some fun and get out once in a while.
    I just have to remind myself that the house has stood for 90 years it’s not going to fall down…then again, if it did it might save me a LOT more time.

    1. Sarah—You just made me laugh, long and loud! My hubby and I did a complete remodeling thing on a 90 yo house over 3 years and often call it remodeling the “granny-shack pit”. We will never do it again! We are now out of the house and can’t believe how much we missed out on all of our activities because we had work hanging over our heads! I can sympathize with the feelings of hoping it will just “go away” somehow…….

  5. Since my father’s cancer diagnosis, my SO and I have been engaging in weekly adventures and it has been wonderful on so many levels – not just stress relief. I keep an ongoing list of ideas for these adventures.

    I also belong to a drum circle that meets twice a month.

    I play tai chi with an awe-inspiring master.

    Read lots of positive health, fitness and self-improvement stuff, and, lately, have been reading children’s literature for stress relief.

    I’ve recently been making collages regarding different topics, and it’s fun!

    I want to make time to learn to play my ukulele.

  6. As a graduate student of engineering, I’m constantly up against a learning curve (new software, new equipment, new methods, etc.). Though in the moment of learning (especially if there’s a deadline), I can feel a bit anxious. I always feel fantastic upon learning something new – and then I get the challenge of teaching it to someone else! Also a bit of stress, but GOOD stress. Granted, I still like the occasional day where I know EXACTLY what I’m doing all day (very little stress), but most of the time I can handle the challenges, and love them! They invigorate me!

    1. I can agree with this, but I’m a physics guy. 😀 I know that feeling all too well.

  7. Just yesterday I scheduled my first ever piano lesson for Saturday. I figured it was time to shorten my “Things I’d Like to Learn” list.

  8. Love it. Great article, and a reminder that I definitely need to work on this aspect of my life.

  9. Great post! I don’t consider having much of a social life now. My 2 good friends recently moved to WA. I have 1 left & doesn’t go out much but loves to talk on the phone lol.

    Just trying to find a job is stressful enough. I’ve been out for just 3 yrs & feel so left behind.

    A Primal Blueprint Fitness & Primal Local Clubs in our area would be great & to think of the many things we have in common & sharing different ideas, recipes, having a good time together & motivating each other. I’m staying tuned alright since you brought it up lol. I love the idea! 😀

  10. Mark, a little quibble. Rats and mice are very different species. They are not interchangeable.

  11. Although I do not envy the lives of mice getting injected with cancer, it’s nice to have more proof that positive stress and an engaging environment both contribute to good health for our fellow mammalians. I found it most interesting that the tumors disappeared entirely in 1/5 of the enriched population after 6 weeks, and I wonder how this compared to the non-enriched sample; favorably, I presume.

  12. Great post to head into the weekend with!

    I will freely admit that I can be guilty of pushing myself too hard and not stopping to smell the roses enough.

    Good to hear more reasons why I should start getting to bed earlier and getting out of the house more on the weekends!

  13. Yes very productive post.Incidentally I live in the UK and am coming to California on Monday for 3 weeks;San Francisco,Yosemite,Santa Monica and Oxnard onto Los Angeles.So I will look out for Grok t-shirts as I sprint along the beach …

  14. I am definitely guilty of letting the bad stressors take over. Here lately, I’ve been trying to turn some of that bad stress into good stress by including my kids in chores around the house and making them a sort of game.

    Also, I have taken to playing “antelope” with the kids as well. (I’m sure it’s more challenging with adults, but you do what you can).

    Still, even in transforming some of my bad stress to good stress, I still find myself feeling wiped out and frazzled. I can definitely say that I’m ready for school to start back for the kiddos. Then, I’ll be able to go back to doing bellydance on my free Wednesday afternoon, and I’ll be able to have Fridays to myself again.

    Sanity, here I come!

  15. Mark,

    Myself being a buckeye, I must point out, the school’s name is “The” Ohio State University.

    Keep up the awesome work!

  16. What is the definition of “Axis” in the world of molecular signaling and what is meant by the “BDNF/leptin axis”?

  17. I would definately join a Primal Tribe Club. I just can’t find anyone (besides my meat supplier from the farmers market) that eats primal. I scout and keep a lookout of people who might be primal every Saturday at the Market, no luck so far.

    I’ve spent hours before watching people shop for produce and they all go home with tons of different breads or a giant bag of beans.

  18. Let’s see — I have a full time job, another old house in need of serious renovation, an 8 month old labrador puppy who needs constant attention and consistent training, and I’m planning a wedding. Booked our honeymoon for the Caribbean — never been there — and my first snorkeling trip!
    I make time for hiking and gaming and, well, I like to sleep.
    Great post! Looking forward to primal fitness stuff!

  19. Well if any you are in, around, pass through, or want to visit NW Arkansas, drop me a line. There are trails here that beg to be hiked, ran, and moutain biked on.
    (that includes you Mark)
    I am a very new Grokker, less than two weeks, but man the difference is amazing in just that short time period!

  20. Anyone in San Francisco? Would be great to play persistance hunting games with someone in the park! 🙂

  21. Great post! We recently went on a “workation” to Costa Rica … a 6-week trip that included some remote work (so that we could afford to stay there longer). There was no shortage of adventure … also a fair amount of stress. I hadn’t thought about the experience from a health perspective, but the trip had a strong psychological impact — higher novelty in every area. Good to know that “changing it up” might have health benefits as well.

  22. Great post again. It is too easy in this society to just get stuck running in the little hamster wheel. Not what we were born for!

    As for local tribes, it would be great even just to have local topics in the forum. I got excited yesterday when I found that my food coop is now selling bulk, OG, extra-virgin coconut oil. Yowza! I wanted to share my glee in a post, but couldn’t figure out where — probably not as exciting to people elsewhere in the world.

  23. Loved this post!! So good.

    I’d love to be involved with starting a Primal Tribe here in Saskatchewan! (It’s in Canada for those of you who don’t know.)

    I already know a coupl, and it’d be great to have sprint sessions with a tribe, sprinting by myself is not quite as fun.