Your Biology Wasn’t Built for Modern Life

Here's how to reduce the friction

The more I study the biology of aging, the more one thing becomes clear:

Our biology functions best under a specific set of conditions.

Modern life has brought enormous advantages.

But it has also quietly removed our access to many of those conditions.

And this friction, I believe, is having real consequences for how we age as a society.

Today, I want to walk you through the specifics of this biological mismatch — and how small adjustments to your environment can better support your biology over the long term.

The Mismatch

For most of human history, our biology developed under a remarkably consistent set of conditions.

Bright natural light throughout the day. Darkness at night. Regular physical activity. Whole foods. Natural environments. Deep periods of rest. Social connection.

These weren’t lifestyle choices. They were simply the conditions of life.

Our internal biological rhythms were shaped around these conditions over an extraordinarily long period of time.

Which means our biology still expects them — even if modern life no longer provides them, or replaces them with artificial ones.

That’s the mismatch.

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Why This Matters Today

Modern life has given us something most previous generations didn’t really have: choice.

We largely get to choose what we eat, how we move, when we sleep, and how we spend our time.

And I’m grateful for that freedom.

But it comes with a trade-off — we now have to be intentional about the very things our biology used to receive automatically.

Nobody had to think about getting morning light when they worked outside. Nobody had to build their own exercise routine when survival demanded it.

Today we do.

And this isn’t just theory — we’re now seeing the effects of this shift reflected in long-term health outcomes.

I’ll walk you through four key areas where this friction shows up most clearly — and how small, intentional adjustments can make a big difference over time.

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1) Light

The need to go outside has largely disappeared. Work and entertainment happen almost entirely indoors under artificial light. In the evenings, screens and overhead lighting keep us in a state of artificial daytime long after sunset.

Our biology runs on light as information. Morning light signals wakefulness, sets our cortisol rhythm, coordinates the timing of key biological processes around the body, and starts the roughly 16-hour melatonin timer for sleep. Evening darkness signals recovery and prepares the body for sleep. Living as close to that natural rhythm as possible is one of the most impactful things you can do for your health.

2) Food

Estimates suggest ultra-processed foods now make up around 50-60% of the average diet in the UK and US — typically high in refined sugars, low in fibre, and stripped of the micronutrients our biology depends on.

Our biology expects real, minimally processed food — quality proteins, fibre, healthy fats, and polyphenols from plant and animal sources — to support everything from cellular repair to cognitive function.

3) Movement

Modern life has made movement optional. This is where choice works against us most.

Fewer than 10% of adults resistance train consistently. Even fewer incorporate mobility work or higher intensity movement. Walking remains the one thing most people do — which is great — but on its own, it’s usually not enough to maintain strength and function long term.

Our biology expects a mix to preserve capacity: regular walking, lifting, occasional intensity, and mobility.

4) Genuine Rest

Genuine rest — unstructured, unstimulated time — has largely disappeared.

For most of human history, periods of doing nothing were unavoidable. No screens. No notifications. Just space to think, connect, and recover. The average person today is exposed to more information and stimulation in a single day than previous generations encountered in months. At the molecular level, chronic stress has real, measurable consequences. More unstructured time isn’t laziness. It’s a biological necessity.

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To Close

These are just a few examples — and this definitely isn't me saying you need to start living like a caveman.

It's just worth understanding that many of the environments we now spend our lives in are genuinely novel to our biology. And that some small, intentional adjustments can have a real impact at the molecular level.

Thanks for reading!

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Disclaimer: This post provides educational information based on scientific research and is not medical advice. It does not establish a doctor-patient relationship. Always consult a qualified healthcare professional before making lifestyle changes, addressing medical conditions, or starting new treatments.