October 23, 2025
Welcome to Ben Greenfield's Weekly Roundup!
In this weekly post, I share with you my most interesting discoveries of the week, including the latest news on the fronts of fitness, nutrition, health, wellness, biohacking, and anti-aging research. I also recap my upcoming events and special announcements so you can keep up with opportunities to learn, giveaways, discounts, and more!
New Discoveries
Why I *Don’t* Use Sunscreen In Specific Cases—And What a New Study Shows About SPF Sabotaging Vitamin D ☀️
Most people don’t realize it, but sunscreen can significantly reduce your body’s ability to produce vitamin D—the “sunshine hormone” that supports immunity, bone health, and overall balance.
A recent meta-analysis of 22 studies involving nearly 10,000 participants found that regular sunscreen use lowers serum vitamin D levels by about 2 ng/mL on average. For someone who is borderline deficient in vitamin D (around 30–35 ng/mL), losing 2 ng/mL from sunscreen use could push them into full deficiency, especially if they also have limited sun exposure or darker skin.
Biologically speaking, it makes sense: sunscreen blocks UV-B rays, the same wavelength needed to convert cholesterol into vitamin D3.
That doesn’t mean you should ditch sunscreen completely.
I still use sunscreen on the thinner, more fragile skin of my face if I plan to be out in the midday sun for more than about half an hour, and I use sunscreen on my whole body if I’m in the sun long enough to burn. (My go-to for sunscreen is Young Goose's Bio-Shield—you can use code BEN10 to save 10% off .)
But smart sun exposure is key—the goal is to get regular, moderate sunlight before applying SPF, so your skin can produce enough vitamin D naturally (for more information, check out my podcast with Young Goose's founder Amitay Eshel here).
Want to dig deeper into why vitamin D and sunlight are so essential for your health? You can check out these resources:
- Sunlight Makes You Skinny & Blue Light Makes You Fat: 11 Ways To Biohack Light To Optimize Your Body & Brain.
- Why Water, Sunlight, Grounding & Relationships Are The Keys To Your Health & How To Feed, Clean & Protect Your Body Forever: An Interview With Ben Greenfield’s Father, Gary Greenfield.
- Q&A 456: Holistic Cancer Management, Supplements To Combine With Sunlight, Constipation Hacking, Super Slow Training & More!
- Ben Greenfield’s Critical 6 “H’s” of Health Optimization for Upgrading Your Body & Brain—Part 1.
- Can a Cultured Mushroom Extract *REALLY* Shrink Tumors, Clear HPV & Supercharge Immunity?, with Meagan Lindquist.
Decoding a Supercentenarian’s Microbiome: Clues to the Biology of Exceptional Longevity (117 Years Old!) 🧬
Maria Branyas Morera, who lived to 117 (and was the oldest verified person in the world), may provide the clearest picture yet of what it takes to outlive almost everyone.
In a groundbreaking Nature study, scientists analyzed her genes, metabolism, immune system, and gut microbiome, discovering a fascinating interplay of nature and nurture behind her extreme longevity.
- She carried rare genetic variants that protected her heart and brain from age-related decline, maintained youthful lipid metabolism with no signs of diabetes or high cholesterol, and had remarkably low inflammation (a hallmark of long-lived individuals).
- Her gut health resembled that of someone decades younger, with abundant Bifidobacteria nourished by her Mediterranean-style diet rich in olive oil, fish, and three daily servings of plain yogurt.
- Even her biological clock ticked more slowly. Despite short telomeres and cellular aging markers, her epigenetic age was younger than her chronological one—a sign that her body was “aging well” under the hood.
Based on these findings, here's what you can learn from Maria…
There’s no single hack for living past 100, but the blueprint is clear: anti-inflammatory nutrition, microbiome diversity, efficient metabolism, and stress-resistant genes work together to slow aging from every angle.
Curious to learn more about how to live longer (and better)? You can start here:
- 12 Basic, Natural & Easy Habits To Enhance Longevity.
- Is Aging Optional? How To Use Genomics-Based Precision Longevity To Enhance Lifespan (& 9 Anti-Aging Compounds).
- Bloodwork, Biomarkers, Biohacking Las Vegas, Optimizing Performance and Longevity & More With UFC Fighter Miesha Tate.
- Could This Controversial, Newly Discovered “Dolphin Drug” Be A *Missing Key* To Longevity? The C15:0 Story, With Dr. Stephanie Venn-Watson.
Most Protein Bars Are Junk Food in Disguise… So I Created *This* Delicious Fix ⚡🧠🍫
I’ve been working on something behind the scenes that is about to change the way you fuel your body and brain, and totally transform the protein and energy bar industry.
As you probably already know, most protein bars (and energy bars in general) are full of junk—they spike your blood sugar, wreck your gut, leave you hungry an hour later, and they taste like cardboard.
Sure, you get protein, but a lot of crap along with it, and not really much appetite satiation or noticeable cognitive upticks at all. 👎
So, based on what I know about the intriguing science of fueling with ketones, I decided to build something totally different…
👉 Meet Boundless Bar—the world’s FIRST ketone-powered protein bar.
Unlike sugar, which burns fast and leads to energy crashes, Boundless Bar is built around goBHB®, the gold standard in exogenous ketones, helping you:
- Fuel your workouts with ketone-backed energy that sustains physical and mental performance for hours on end.
- Stay sharp at work with enhanced mental clarity, memory recall, and focus.
- Support recovery and repair with collagen for muscles, joints, skin, and connective tissue.
- Curb cravings with satisfying protein and ketone-driven appetite control.
- Optimize your aging with ingredients that promote cellular resilience and whole-body vitality.
Every Boundless Bar includes:
🍖 18g of hydrolyzed collagen protein to support muscle recovery, joint health, hair, and skin.
🔥 260–270 calories (depending on the flavor) with healthy fats from cashew butter and cocoa butter to keep you fueled.
⚡ goBHB® ketones for rapid, stable energy without stimulants, sugar crashes, or jitters.
🚫 Zero seed oils, gluten, dairy, or soy for guilt-free, gut-friendly nutrition.
🍯 Honey and monk fruit for a naturally balanced, indulgent flavor.
And forget the chalky taste of typical protein bars or the nasty aftertaste of most ketone products—with Boundless, you can choose from two delicious flavors (more to come, including Blueberry Pie and Chocolate Chip!):
- 🍯 Cinnamon Roll Bar (just 270 cal): Blends real cinnamon spice with creamy cashew butter and a touch of honey and monk fruit, delivering the taste of a cinnamon roll with the fuel of a performance product.
- 🍰 Vanilla Cheesecake Bar (just 260 cal): Combines smooth vanilla with a rich, creamy texture, giving you the indulgence of cheesecake in your pocket—without the sugar crash.
Both flavors make it easy to stay on track while enjoying every bite, providing you with clean fuel and a smarter, all-day ally to p
ower your brain, body, and future.
Normally, to achieve ketosis, you have to suck down a bitter drink, fast for days, or engage in strict carb restriction. But now you can quite literally eat your way into ketosis with a delicious low-calorie, high-protein bar that satisfies your appetite and powers your day for hours on end.
Are you ready to experience the power of ketones and step into a Boundless you?
You can click here to purchase your Boundless Bars and save 10% off your subscription.
These JUST went live and will disappear fast like hotcakes, so get yours soon!
Tired of Being the “Healthy One” Everywhere You Go? *Here's* How to Find Your People & Your Places 🥗📍
I co-founded LIFE Network with my best friend Caleb Applegate to bring together a community of health seekers, biohackers, and purpose-driven humans—people passionate about living fully optimized in body, mind, and spirit.
Now we’ve launched two new features that make it easier than ever to connect, explore, and grow:
👥 Groups: Join focused conversations on longevity, peptides, fitness, nutrition, and more. Groups make it simple to connect with others who share your passions and support your personal journey.
📍 Places: Discover and share healthy restaurants, gyms, and wellness hubs near you—or wherever you travel. It’s your guide to real-world spots that align with your lifestyle.
These updates are all about deeper connection, stronger community, and living life to the fullest.
👉 You can start discovering your people and favorite places by joining LIFE Network for free.
*Here’s* How to Receive Coaching, Workouts & Biohacking Support—with TRIUMPH Coaching
I get it—navigating your health and fitness in today’s world can feel like chasing a moving target. One week, it’s about your macros, the next, it’s wearables and peptide stacks.
When was the last time you had an actual team helping you sort through the noise, guiding you step by step based on your unique biomarkers, goals, and lifestyle?
With TRIUMPH Coaching, you gain access to elite-level support without the guesswork.
We have different coaching plans to meet you wherever you are. Work 1-on-1 with one of my expert coaches, or as part of a group. Whatever you choose, you’ll be rooted in real-time adjustments and results. If your goals involve optimizing VO2 max, chasing longevity, or just trying to build muscle and mobility right from your living room, we’ve got you covered.
Want to explore your TRIUMPH coaching options?
Fill out our coaching form, and one of our expert coaches will reach out to discuss how to help you achieve extraordinary fitness and peak performance.
This Week in Health & Performance: What the Latest Research Says
🥩 Protein Source Matters, But Context Is Everything: A new study found that leaner pork actually led to better muscle protein synthesis than fattier cuts (study here), while previous research showed the opposite with eggs: whole eggs (with yolks) stimulated greater muscle building than egg whites alone (study here). Protein quality, fat content, and matrix clearly matter more than macros alone.
🏀 Creatine Boosts Cognitive-Physical Performance in Athletes: In young basketball players, creatine supplementation (0.3g/kg/day, split into 4 doses) improved performance and lowered perceived exertion during high-cognitive-load drills—proof that creatine’s benefits go beyond muscle and extend to brain endurance (read the study).
🧬 Spermidine’s Anti-Aging Power Is Dose-Dependent: This new trial found that spermidine only improves aging biomarkers like mitochondrial function and cell renewal at higher doses (3mg+), suggesting more is better for meaningful longevity effects (full study here).
🌫️ Air Pollution Linked to Dementia Risk: A meta-analysis of 32 studies in over 26 million adults found that long-term exposure to air pollution modestly increases dementia risk (study here). To reduce indoor exposure—the air you breathe 90% of the time—check out my episodes with Mike Feldstein of Jaspr Air Purifiers here and here.
Key Takeaway: From protein quality and creatine cognition boosts to spermidine dosing and clean air strategies, this week’s science highlights how small, smart interventions can profoundly impact longevity and performance.
🔗 Want to dive deeper? Click the links above to explore the research, and click here to follow me on X for all the latest health and performance news hot off the press! 🚀
Product Of The Week
::: Build a Bulletproof Gut & Beat Bloating Naturally (Save 20%) 🌿 :::
If you deal with bloating, cravings, or that “heavy” feeling after meals, the Just Thrive Gut Essentials Bundle is your new secret weapon for total digestive balance.
This bundle pairs two clinically proven gut superstars: Just Thrive Probiotic and Digestive Bitters.
The probiotic boasts 1,000x better survivability than leading brands and arrives 100% alive in your gut, where it makes antioxidants and supports digestion, immunity, mood, sleep, and skin from the inside out.
Meanwhile, Digestive Bitters revive 12 time-tested herbs that naturally jumpstart digestion, reduce bloating, improve nutrient absorption, and even boost GLP-1 production to help tame cravings—all without the bitter taste.
The bitters kickstart digestion, the probiotic strengthens your microbiome, and together, they help you beat bloat, improve regularity, and restore true gut balance.
You can try the Just Thrive Gut Essentials Bundle and save 20% automatically when you use this link.
Podcasts I Recorded This Week:
The Latest Content I Was Featured On This Week:
My Article Feed:
My full article feed and all archives of my articles are here.
Upcoming Events:
Stay tuned for future updates—and you can always keep up with my LIVE appearances by checking out bengreenfieldlife.com/calendar!
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Cheers,
Ben