TODAY'S AJENDA #74

In 1929, Danish scientist Henrik Dam fed chickens a fat-free diet and noticed something alarming: the birds were bleeding because their blood wouldn’t clot. This discovery earned Dam a Nobel Prize and introduced the world to Vitamin K, the vitamin we associate with blood clotting today. 

But that’s only half the story. Dam had uncovered vitamin K1 (phylloquinone), but vitamin K2 (menaquinones) would later emerge as a potential game-changer for bone and cardiovascular health. 

96 years after Dam’s discovery, researchers are now asking: Does K2 deliver? Let me take you through the science.

What Vitamin K2 Does

The short answer: Vitamin K2 tells calcium where to go. 

The long answer? Vitamin K2 activates two key proteins that manage calcium in the body: osteocalcin, which helps bind calcium to bones and teeth, and matrix Gla protein (MGP), which prevents calcium from depositing in blood vessels. K2 shuttles calcium into bones and teeth (where you want it) and keeps it out of arteries and soft tissues (where you don’t).

“What food has Vitamin K2?” K2 isn’t in your typical grocery store produce aisle. Instead, it hides in fermented foods and animal products: 

• Natto: This Japanese fermented soybean dish contains more than 100 times the amount found in other sources. 

• Hard Cheeses: Gouda, Brie, and other aged varieties. 

• Egg Yolks and Dairy: Eggs from pasture-raised chickens and dairy from grass-fed cows. 

• Organ Meats: Liver, heart, spleen, etc.

What Does The Science Say? 

That K2 may:  

• Reduce Fractures: A meta-analysis found that K2 increased bone density and reduced fractures by 60-81% in Japanese studies.

• Protect Arteries: The Rotterdam Study found that people with the highest K2 intake had 52% less arterial calcium buildup and 57% lower risk of dying from heart disease compared to those with the lowest intake.

There’s also research suggesting K2 could help strengthen bones. A 2022 analysis involving over 6,400 postmenopausal women found that K2 supplements improved bone mineralization and strength. 

But here’s the thing: A 2023 review found mixed results in recent trials. This brings us to one of vitamin K2's biggest cons: there isn’t enough data to prove cause and effect yet. 

There are a few more cons: 

• Supplement Quality: The supplement world is like the Wild West. K2 products aren’t regulated like medications, so quality may vary.

• Interactions: Vitamin K (including K2) can clash with anticoagulant medications like warfarin. 

• Cost: High-quality K2 supplements aren’t exactly wallet-friendly. 

Bottom Line 

So, would I hand you a bottle of vitamin K2 if I were your doctor? It depends. If you’re a woman over 50 who is concerned about their bone health, it deserves a spot on your radar. But if you’re on blood thinners? Likely not, as it may interfere with your medication. 

As always, the best course of action is a balanced diet and exercise. And give natto a try if you haven’t already. The slimy texture isn’t for everyone, but its health benefits definitely are. 

“I don’t sleep well….” 

I’ve heard this from countless women struggling with sleep as they age. They’ve tried everything from melatonin, chamomile tea, to strict screen-time curfews, yet that deep 8-hour sleep still feels (no pun intended) like a distant dream. 

The problem may lie inside your sleep routine. It could be the temperature, both of the air in your bedroom and of your body.  

The Temperature of the Room and Body 

Temperature can make or break your sleep efficiency. But what exactly is sleep efficiency? Simply put, sleep efficiency measures how much time in bed you spend actually asleep.  

For example, say you go to bed at 10 PM and get up at 6 AM (8 hours in bed). But you spend the first hour tossing and turning and get up at 3 AM to pee and can’t fall back asleep for another 30 minutes. 

Out of those 8 hours, you were asleep for 6.5. This puts your sleep efficiency score at 81%. 

Research shows that people’s sleep efficiency is best when their bedrooms are between 68-77 °F (that’s 20-25 °C for our non-American readers). But push that thermostat to 86 °F, and sleep efficiency drops by 5-10%. 

Why? Because room temperature either supports or sabotages your body’s natural cooling process. 

• Zoom In: Each night, your core temperature drops to conserve energy and help the brain clear out metabolic waste. If the room is too warm, that cooling becomes harder, and sleep suffers.

How Menopause Impacts Sleep

This body cooling process is already delicate. Unfortunately, menopause throws a wrench into the whole system. As estrogen levels drop, your internal thermostat goes from reliable to unpredictable. 

Estrogen helps regulate your hypothalamus (your body's temperature control center), so with less of it, your body becomes hypersensitive to temperature changes and struggles to maintain that steady cooling you need for quality sleep.

The result? Those dreaded 2 AM hot flashes, where you wake up drenched in sweat or feeling like a nuclear reaction is occurring in your core. (I never had the drenching part but I did have the nuclear reaction experience. Not fun.) 

How to Improve Your Sleep 

How to harness temperature to your sleep advantage:  

1. Shower Before Bed. Though this sounds counterintuitive, take a warm 10-minute shower (ideally 104-108.5°F) 1-2 hours before bed. A 2019 meta-analysis found it shortened sleep onset latency (the time it takes to fall asleep) and improved sleep efficiency. 

2. Keep Hands and Feet Warm. Warming your extremities creates heat exit pathways that help your core body temperature drop. Use a heating pad, layered bedding, or wear socks. A small 2018 study found that wearing bed socks increased total sleep time by 32 minutes. 

3. Set Room Between 68-77 °F. Think gentle, cool, not misery! If you sleep cold and resent me in the morning, we have missed the point. I sleep at 67 degrees and absolutely love it, and my husband has gotten used to it :-)  

These strategies work well and cost almost nothing. But if you're ready to take your sleep seriously, especially if you're dealing with menopause hot flashes, there's new technology that can make a world of difference. 

Enter: The Eight Sleep Pod 5.* It’s a smart mattress cover that goes on top of your existing mattress. This is next-level sleep tech. It automatically regulates your body temperature throughout the night, independently for each side of the bed. The result is up to one full hour of additional sleep each night! 

But what’s next-level about Pod 5 is that it was designed for women instead of defaulting to male physiology (as most products do). When you feel a hot flash coming on, you can activate Hot Flash Mode for instant cooling that lasts up to 30 minutes. The results: 

• 8 out of 10 women felt hot flash relief within 10 minutes of using Hot Flash Mode 

• 34% of users reported deeper levels of sleep 

• 44% reported falling asleep faster 

Cost comment: This next gen (or JEN) sleep technology is not cheap, but I do believe the investment in sleep and subsequent health outcomes is truly priceless. Every single thing in our lives is predicated on good sleep to occur, and as we age, sleep is the glue that holds our wellness together. In the spectrum of pricey behaviors or purchases that have an impact on our wellbeing, this is one I personally and professionally feel deserves to be high on the list.

If you're having sleep issues, this high tech sleep product could be for you. Try it risk-free for 30 days with code DRJEN for $350 off. 

A drug discovered in the soil of a remote Pacific island in 1964 could slow down the aging process. It sounds like something straight out of a pharmaceutical fever dream, but this isn’t science fiction. 

Meet: rapamycin. This compound, also known as sirolimus, has captured our imaginations as an anti-aging drug. But does it have potential as a longevity elixir? 

The Origins of Rapamycin 

Rapamycin was first an obscure immunosuppressant drug for organ transplants. It wasn’t until the 2000s that researchers discovered it could extend the lifespan of mice, worms, flies, and yeast. 

• Science Says: A 2016 study found that giving mice rapamycin extended their lifespan by 2 months. The final rodent survivor died more than two years after the experiment at 3 years and 8 months. That’s about 140 in human years! 

What Rapamycin Does in the Body 

This probably sounds like snake oil to you (it did for me at first, too), so let me explain rapamycin’s biological effects.

Basically, rapamycin tricks your body into caloric restriction mode. This is when you eat fewer calories, but your body becomes more efficient and resilient. 

• Zoom In: This is an evolutionary survival trick. When food is limited, your body assumes tough times are ahead, and your cells shift focus to repair and cleanup instead of building new tissue. 

“How does rapamycin do this?” It blocks a cellular pathway called mTOR (mammalian* target of rapamycin). Think of mTOR as a switch. When it’s turned off, the body goes into survival mode. Rapamycin flips that switch off.  

The Science of Rapamycin on Humans

Human trials with rapamycin aren’t testing for longevity. That would be almost logistically impossible. Instead, scientists are looking at whether rapamycin improves our body’s systems, like immunity and skin health, over time. 

The science has found: 

• Immune Boosting. A 2014 study found that low doses of rapamycin-like drugs boosted flu vaccine responses in elderly people by 20%. (NOTE: Dose matters. A high dose was found to weaken immunity.)

• Improved Skin: In 2019, researchers found that topical rapamycin cream applied to aging hands for 6-8 months reduced “zombie cells” and increased collagen production, leading to fewer wrinkles and more dermal volume. 

• Heart Health: A study of 10 people with severe heart disease found that everolimus, a rapamycin-like drug, improved heart function over 6 months. (NOTE: Larger studies are needed to better understand rapamycin’s effect on heart health.) 

The Cons of Rapamycin 

They include: 

• Physical Side Effects: Mucosal ulcers, rashes, delayed wound healing, elevated cholesterol and triglycerides, low blood cell count, and menstrual problems. 

• Drug and Food Interactions: Rapamycin is broken down by liver enzymes (CYP3A4) and cleared by transport proteins (P-glycoprotein). If these are blocked by antibiotics, antifungal drugs, or even grapefruit juice, rapamycin can build up in your system, raising the risk of nasty side effects. 

• Dampens Immunity: Rapamycin weakens your immune system’s ability to safely handle live vaccines (e.g., measles, mumps, rubella, etc).  

Should A Woman Over 50 Take Rapamycin? 

Here’s my sober view: If you’re curious, treat this as a clinical experiment (not a solo biohack). That means: 

1. Partnering with a credentialed physician who understands mTOR inhibitors. 

2. Nailing the health fundamentals. Sleep, protein, resistance training, blood pressure, lipids, and glucose control move the longevity needle most. 

3. Creating a proper protocol. Low intermittent doses, baseline labs plus regular monitoring for lipids and glucose, a review of drug interactions, smart vaccine timing, and no elective surgery during initiation. 

If you expect a miracle, you’ll be disappointed. If you expect a careful test of a plausible aging target, you’ll be aligned with the actual science. 

That said? It’s still early days for rapamycin. There are many clinical trials underway, including tests on muscle strength and endurance in older adults, ovarian aging, Alzheimer’s, and more. I’ll keep you updated on the latest science as soon as it’s fresh off the press. 

If you’d like to ask me your questions directly, go to my Instagram. 

Important Clarification: Rapamycin

*I've gotten a few questions from Ajenda readers about the terminology of mTOR in the article I wrote about Rapamycin. 

Our medical editing team and I wrote it using the newer terminology, m = mechanistic,  though I thought I actually should have used the more familiar m = mammalian terminology that most of the older literature uses. 

Though a few readers may have interpreted this as an error, it's really a great example of shifting terminology, prompted by new information. I researched the change in terminology and wanted to share it with you:

• mTOR originally stood for “mammalian target of rapamycin.” That was the name given when it was first described in the early 1990s, because rapamycin was the compound that inhibited it, and it was identified in mammals as the analog of a yeast protein (TOR). 

• Around 2009, the field began formally shifting terminology. The official update came from the HUGO Gene Nomenclature Committee and IUPHAR (the receptor nomenclature authority). They endorsed “mechanistic target of rapamycin” to reflect that mTOR is the central kinase in the TOR signaling pathway, regardless of species.

• Journals and review papers started adopting it, though many would put both terms for a while: mTOR (mechanistic, formerly mammalian, target of rapamycin). Today, the preferred and more accurate term is “mechanistic target of rapamycin.

• The reasoning is that the pathway is highly conserved across species, not just mammals. To avoid species-specific language, the nomenclature was updated.  

So, if you’re writing for a modern scientific or medical context (or Ajenda's Newsletter) the correct terminology is: mTOR = mechanistic target of rapamycin.  That said, you’ll still see mammalian in older literature or in casual conversation. But journals, conferences, and most researchers use mechanistic now.

Thanks to Dr. Avrum Bluming, author of  the great book, Estrogen Matters, for emailing me about this terminology. I would have been outdated by using the term I wanted to initially use (mammalian) but fortunately our incredible newsletter editor was even more current than I, and corrected it to the modern, more current term (mechanistic)!

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ABOUT DR. JEN

In her former roles as chief medical correspondent for ABC News and on-air cohost of “GMA3: What You Need to Know,” Dr. Jennifer Ashton—”Dr. Jen”—has shared the latest health news and information with millions of viewers nationwide. As an OB-GYN, nutritionist, and board-certified obesity medicine specialist, she is passionate about promoting optimal health for “the whole woman.” She has authored several books, including the national best-seller, The Self-Care Solution: A Year of Becoming Happier, Healthier & Fitter—One Month at a Time. And she has gone through menopause…

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