Sleep, Circadian Rhythm, and Heart Health: Your Cheapest “Longevity Drug”

A lot of my patients live on great coffee, good intentions, and not quite enough sleep.

Their labs are “fine.” Their wearables say they sleep “okay.” But they feel wired, tired, foggy, and a little heavier every year.

Recently, the American Heart Association published its first scientific statement on circadian health and cardiometabolic disease risk in Circulation. It pulls together evidence that the timing and regularity of sleep, light, food, and movement meaningfully shift risk for obesity, diabetes, high blood pressure, and cardiovascular disease.

At the same time, a recent Nature article feature on sleep highlights how this thing that takes up roughly a third of our lives is still revealing its impact on brain, immune, and metabolic health.

The message from both:

Sleep isn’t just “rest.” It’s a daily timing signal that your heart, metabolism, and brain depend on.

Your body clock quietly drives your heart and metabolism

The AHA statement defines circadian health as the optimal function and alignment of your internal 24-hour clock with the light–dark cycle and daily behaviors. When that system is out of sync—because of irregular sleep, late meals, light at night, or shift work—risk goes up for:

     • Obesity and weight gain
    • Type 2 diabetes
    • High blood pressure
    • Cardiovascular disease

This isn’t only a problem for night-shift workers.

Irregular bed and wake times. “Social jet lag” — very different weekday vs weekend schedules — is linked with worse cardiometabolic profiles, even when total sleep time looks okay.

Light at night. Night-time light exposure (streetlights, screens, bedside lamps) disrupts circadian signaling and is being tied to higher rates of hypertension and cardiovascular disease.

Four moves that do most of the work

1️⃣ Lock your wake time

If you only change one thing, make it your wake time. Pick a wake time you can keep most days of the week and protect it ruthlessly.

Your circadian system cares most about when you wake and get light, not when you promise you’ll go to bed. Shrinking weekday–weekend swings cuts “social jet lag” and is associated with healthier weight, blood pressure, and glucose.

Perfect regularity is impossible. Narrowing the swing to about an hour is realistic and surprisingly powerful.

2️⃣ Use light like a drug

Morning: strong dose. Get outside or near bright natural light within 1–2 hours of waking, even for 10–20 minutes. It helps lock in daytime alertness and sets up melatonin to rise on time at night. 

Evening: gentle taper. In the 1–2 hours before bed, think cozy restaurant lighting—warmer, dimmer, fewer harsh overheads.

Night: minimal exposure. Make your bedroom as dark as practical. The AHA statement specifically calls out circadian disruption from light at night as a contributor to cardiometabolic risk.

None of this is flashy, but it’s more physiologically meaningful than most “sleep hacks.”

3️⃣ Shift calories and stimulants earlier

The AHA statement emphasizes that when we eat and drink is part of circadian health. Late-night calories and stimulants distort glucose handling and sleep quality.

Large meals. Finish bigger meals 2–3 hours before bed so you’re not trying to sleep on a full, actively digesting stomach.

Caffeine. Cut off caffeine 8-10 hours before bedtime; some people need even longer. If sleep is fragile, this is often one of the highest-yield tweaks.

Alcohol. It can help you fall asleep faster but reliably fragments sleep and reduces deep sleep — a bad trade if you care about recovery and long-term health.

We can get fancier later with time-restricted eating or CGM-guided experiments. These basics already move the needle for most people.

4️⃣ Get moving; fine-tune timing later

Exercise is also a circadian signal, but the first question is simply:

“Are you moving enough each week?”

The evidence base still supports the classic target: around 150 minutes or more of moderate aerobic activity plus at least 2 days of strength work weekly.

Only once that’s in place, then timing tweaks make sense:

    Many people sleep better if very intense workouts happen earlier in the day but a neighborhood walk after dinner beats nothing at all.

Sleep as a serious health risk factor, not just “feeling rested”

The Nature article underscores that sleep is doing intensive “behind-the-scenes” work: waste clearance in the brain, memory consolidation, immune modulation, and likely influencing dementia risk over decades.

Chronic short or fragmented sleep has been linked to:

     • Worse attention, memory, and mood
    • Higher rates of depression and anxiety
    • Increased risk of cardiometabolic disease and earlier mortality

So when we optimize sleep, we’re not chasing a vanity metric on a wearable. We’re stacking the deck for heart, metabolic, and brain health at the same time.

When it’s more serious

Some sleep issues are not going to be fixed by better lamps and earlier dinners.

Things I listen for:

     • Loud snoring, gasping, or witnessed pauses in breathing
    • Waking unrefreshed despite long time in bed
    • Severe, persistent insomnia
    • Restless or “creepy-crawly” legs at night
    • Night-time palpitations or chest discomfort

These can signal conditions like obstructive sleep apnea, chronic insomnia, or restless legs syndrome that deserve proper evaluation, often including formal sleep testing and targeted treatment.