Why Jet Lag Hits Harder As You Age (And the Circadian Science Behind It)

The circadian system isn't a fixed mechanism that operates identically across a lifetime. It's a dynamic biological clock that ages with you.

Laboratory studies have demonstrated that the sleep of older adults is considerably more sensitive to circadian timing than the sleep of younger adults, making older adults more vulnerable to circadian rhythm sleep-wake disorders – jet lag included. In essence, the margin for error narrows with each passing decade. A younger circadian system can absorb a six-hour time shift with relative elasticity. An older one has less of a buffer – and feels every hour of the discrepancy more acutely.

This isn't a fringe finding. Jet lag is formally classified as one of several circadian rhythm sleep-wake disorders, characterized by an inability to fall asleep, remain asleep or wake at the desired time when the internal clock and the external environment fall out of sync. With age, the system governing that synchrony simply becomes less resilient.

Morning & Night harnesses the power of your circadian rhythm, helping your body to align to new time zones with relative ease.

Does poor sleep impact your ability to concentrate, perform tasks and function the next day? You’re not alone. The consequences of circadian disruption extend well past feeling tired. A 2024 study published in Scientific Reports examined circadian alignment in older adults and found measurable associations between circadian rhythm stability and cognitive performance – including memory, processing speed and executive function. The researchers noted that jet lag and other causes of severe circadian disruption have been linked to cognitive impairments and reduced memory function across multiple studies.

Other recent research has connected weaker, more irregular circadian rhythms in older adults to increased frailty risk over time, tracked across a 16-year cohort study. None of this means an occasional long-haul flight will accelerate cognitive decline – but it does mean that the "I'll just push through it" approach many of us relied on at 30 carries a different cost calculus at 55 or 65. Supporting circadian resilience isn't merely about comfort. It's about protecting the systems that keep you sharp, steady and well – no matter where you are in the world.

Founded by biologist Dr Sara Palmer-Hussey after giving birth to her first child, Morning & Night was designed to address disruption in circadian rhythm during the natural ageing process. Rather than offering a single, undifferentiated dose of nutrients regardless of time of day, our formula works in two precisely timed phases that mirror your body's own daily rhythm – an approach known as chrononutrition.

The Morning formula supports the defensive, energy-producing phase of your day. Antioxidants including Vitamin C, Vitamin E and selenium help offset the oxidative stress that compounds with travel and disrupted sleep, while CoQ10 and acetyl-L-carnitine support mitochondrial energy production – especially relevant when jet lag leaves your cellular energy systems running on a deficit.

The Night formula is formulated to support the reparative, regenerative phase your body relies on most heavily during sleep – precisely the phase that becomes harder to access efficiently with age and harder still when circadian rhythms are thrown off by travel. Amino acids and magnesium support the cellular repair processes that aging slows and jet lag interrupts, helping your body make the most of whatever sleep it does manage to get during readjustment.

Used consistently (not just around travel, but as a daily practice), Morning & Night helps reinforce circadian stability over time, supporting the kind of rhythm resilience that research suggests matters increasingly as we age.

Some jet lag is inevitable, but you can still enjoy your holiday with a few modest adjustments:

Start adjusting before you fly. Shifting sleep and meal timing by even an hour or two in the days before departure gives an ageing circadian system a head start.

Prioritise light exposure strategically. Morning light at your destination helps recalibrate the clock; evening light delays it. This matters more as circadian flexibility narrows with age.

Don't mistake clock adjustment for full recovery. As the research shows, your internal rhythm may resynchronise while sleep quality still lags – build in genuine recovery time rather than assuming you'll bounce back the moment the jet lag ‘should’ be over.

Support cellular repair year-round. Because circadian resilience is cumulative, consistent support – through sleep hygiene, light management, and circadian-timed nutrition with Morning & Night – matters more than anything done reactively after landing.