How Old Are You Really? Part 3. Rewinding the Clock (Sort Of)
How to slow, stop, and maybe even reverse biological aging.
You’ve seen the headlines, millionaires getting plasma infusions from teenagers, tracking 100 biomarkers a day, eating only between 6:45 AM and 1:11 PM, all with the goal of turning back the clock. Biohacking is everywhere, but what does that even mean?
At its flashiest, biohacking includes things like:
Plasma transfusions
Glucose-monitoring implants
IV vitamin infusions
Full-body MRI scans every three months
Spending millions to “optimize” organs (whatever that means)
At its simplest, it’s:
Tracking your steps with a smartwatch
Drinking coffee with collagen
Cold plunging into an alpine lake
There’s a tension here. Some biohacking practices are grounded in real science. Others are just wellness marketing dressed up in lab coats. The risk is that the noise drowns out the signal, and the real signal is this:
You don’t need to become a walking science experiment to slow biological aging or spend millions of dollars on unnecessary tests. You just need to get the fundamentals right.
Biological Age Is Plastic
As we covered in Part 1, biological age isn’t fixed. It can speed up or slow down depending on your environment, lifestyle, and how you manage stress. We now have tools that can measure and track it (see Part 2), and even show how certain behaviors affect it over time.
In this post, I will walk you through five actionable areas to slow aging. I’ll just say that brevity has never been my thing. As I started writing this, I realized that each area really deserves its own attention, so this post is meant to give you the 30,000-foot view and in future posts, I’ll dive deeper into each area.
1. Exercise: The Anti-Aging Drug
If I had to choose one intervention to slow biological aging, it’d be exercise. It acts on nearly every hallmark of aging (see Part 1 for a refresher on the hallmarks of aging). It improves mitochondrial function and glucose regulation, and reduces inflammation and DNA damage, among many other benefits.
But here is what everyone gets wrong.
You don’t need to train like an Olympian. The goal isn’t to be elite, rather it is to stay independent, mobile, and sharp into your 70s, 80s, and beyond.
Just moving more has profound benefits. For example, replacing 30 minutes of sitting with light (walking for pleasure, household chores) or moderate physical activity (brisk walking) reduces the risk of overall and cause-specific mortality substantially (see this article).
What helps:
Walk for 30-45 minutes most days of the week
Resistance training 2–3x per week
Adding a few power movements for mobility (stair climbs, light jumps) and balance work to prevent falls (think yoga or even standing on one foot)
There’s a lot more to say about exercise and muscle health to promote healthy aging; I’ll go deeper in an upcoming post.
2. Sleep: Your Daily Dose of Restoration
Everyone knows when they’ve had a poor night of sleep. You feel tired, foggy, and maybe a little spicier than usual. Why? Sleep is when your body does critical maintenance. It regulates hormones, clears waste from the brain, repairs tissue, strengthens the immune system, and helps regulate emotions. Waking up in the night (fragmented sleep), disrupts all of those processes. Sleep isn’t optional. It’s foundational and biologically necessary.
As a mom of two young kids, I get how hard it is to protect your sleep. Still, even small changes can make a difference.
What helps:
Going to bed and waking up at the same time
Getting morning daylight (outside - not through windows or sunglasses) and avoiding artificial light at night
Keeping the bedroom dark, cool, and screen-free
Capping caffeine after lunch and minimizing alcohol before bed
Poor sleep isn’t just an inconvenience; it’s a biological stressor. In future posts, I’ll dive into the fascinating story of why we sleep, how sleep and circadian rhythms change as we get older, and what you can do about it.
3. Diet: Fueling Longevity Without Starvation
Let’s be honest, diet research is messy. We're dealing with food recall errors (can you remember what you ate last Tuesday?), celebrity fad diets, and animal diets that don’t translate well to human life. No wonder people are confused.
One of the most well studied anti-aging interventions is caloric restriction (i.e., eating less calories). It has been shown to slow aging and extend lifespan in animal studies spanning many different species. In human trials like CALERIE, caloric restriction modestly slowed biological age using one epigenetic clock (DNAm DunedinPace), but not others (PhenoAge and GrimAge, see this article). The difference in the results could be because the DunedinPace clock measures how fast you’re aging, while the other epigenetic clocks measure how old you are.
Less evidence exists for specific diets, like plant-based diets (e.g., the mediterranean diet) and ultra-low carbohydrate diets (the ketogenic diet), see this review paper.
My personal opinion - eat in a way that supports metabolism, preserves muscle, and reduces inflammation.
What helps:
Eat real food. Leafy greens, colorful veggies, fish, lean meat, legumes, eggs, nuts, dairy, and fruit are your friends
Prioritize eating enough protein (1 gram of protein per pound of body weight a day is a solid starting point)
Limit ultra-processed foods. If it has 40 ingredients and you can’t pronounce half of them, it's probably not helping your aging trajectory
4. The Social Environment: What Happens To You Happens In You
Would you believe that feeling isolated from others carries the same health risks as smoking? It’s true. We don’t usually think of loneliness, trauma, racial discrimination, or poverty as aging accelerants, but they are all forms of chronic stress. Chronic stress messes with immune regulation, speeds up epigenetic aging, and shortens telomeres. The body remembers.
What helps:
Regular (even brief) check-ins with people you love and trust
Building local, in-person community over time
Having micro-practices that help you regulate (deep breaths, nature walks, journaling)
Getting help, if you need it
In the aging space, we talk a lot about biomarkers, but meaning, purpose, and human connection might be the most underrated metrics of all.
5. Alcohol and Smoking: Accelerators of the Biological Clock
It’s no surprise that smoking and excessive alcohol use are bad for your health, but their impact on biological aging is deeper than most people realize. Both are associated with accelerated aging at the cellular level, including increased DNA damage, shortened telomeres, mitochondrial dysfunction, and chronic inflammation. These changes don’t just increase disease risk, they literally speed up your biological clock.
Smoking in particular is linked to changes in nearly all the hallmarks of aging. Woah. It triggers oxidative stress, impairs DNA repair mechanisms, accelerates immune aging, and is strongly associated with earlier onset of frailty, cognitive decline, and mortality. Alcohol, especially in high and habitual doses, alters gene expression through epigenetic changes, promotes cellular senescence, and worsens inflammatory signaling. Even moderate alcohol consumption has been associated with elevated biological age in some DNA methylation studies, especially when combined with other risk factors like poor sleep or diet.
The silver lining? The benefits of quitting start quickly. Studies show that biological age can slow, and in some cases, even reverse after cessation.
The Bottom Line
Slowing biological aging isn’t about hacks. It’s about consistently showing up for your body in the ways that matter.
Move more. Sleep better. Eat real food. Stay connected. Manage stress. None of it is flashy, but all of it is important.
We’ll dive deeper into each area in future posts, and others not covered here, so make sure you’re subscribed. If there’s a topic you want me to prioritize, hit reply or leave a comment.
More soon,
—Jen
Disclaimer: This newsletter is for informational and educational purposes only. It is not medical advice and should not be used to diagnose, treat, or cure any condition. Always consult with a healthcare provider before making changes to your health routine.
For your reading pleasure:
Martinovich, 2024, Climbing the longevity pyramid: overview of evidence-driven healthcare prevention strategies for human longevity, Frontiers in Aging
Garatachea et al., 2015, Exercise Attenuates the Major Hallmarks of Aging, Rejuvenation Research
Dr. Vivek Murthy, 19th & 21st Surgeon General of the United States, Vice Admiral, United States Public Health Service, 2025, My Imparting Prescription for America.