Insomnia

Insomnia and why it matters for longevity

Insomnia is the most common sleep disorder worldwide, affecting 10-30% of adults at any given time, with another 10-15% meeting criteria for chronic insomnia disorder. It's defined by persistent difficulty falling asleep, staying asleep, or waking too early, combined with daytime consequences like fatigue, poor concentration, and irritability. Chronic insomnia means these problems occur at least three nights per week for three months or longer.

The longevity implications are serious. A 2025 meta-analysis in GeroScience found that imbalanced sleep increases mortality risk by 14-34% ^[1]. People with insomnia have a 53% higher risk of cardiovascular death and a 48% higher risk of heart attack compared to good sleepers ^[2]. Sleep insufficiency was associated with reduced life expectancy at the state level across the US, ranking as a stronger predictor than diet or exercise ^[3]. This isn't just about feeling tired. Insomnia accelerates biological aging through oxidative stress, chronic inflammation, and HPA axis dysregulation.

What causes insomnia

Insomnia rarely has a single cause. It usually results from a combination of factors that feed off each other. Psychological hyperarousal is the most common driver: anxiety, rumination, and worry about sleep itself create a self-reinforcing loop where the bed becomes associated with wakefulness rather than rest. Depression, chronic pain, gastroesophageal reflux, sleep apnea, and restless leg syndrome frequently co-occur with insomnia.

Circadian rhythm disruption from irregular sleep schedules, shift work, or excessive evening light exposure desynchronizes the body's internal clock. Medications including stimulants, certain antidepressants, corticosteroids, and beta-blockers can impair sleep. Caffeine has a half-life of 5-6 hours, meaning a coffee at 2 PM still has half its caffeine circulating at bedtime. Alcohol, despite feeling sedative, fragments sleep architecture and suppresses REM sleep in the second half of the night. Hormonal changes during menopause are a common but underrecognized trigger, with up to 60% of menopausal women reporting sleep disturbances.

CBT-I: the gold standard treatment

Cognitive behavioral therapy for insomnia (CBT-I) is the recommended first-line treatment by every major sleep medicine guideline. A 2025 meta-analysis of 32 studies with 5,231 participants found very large effect sizes for insomnia severity reduction, with 45% achieving remission after treatment and 51% at follow-up ^[4]. CBT-I works through several components: sleep restriction (matching time in bed to actual sleep time), stimulus control (using the bed only for sleep), cognitive restructuring (breaking the anxiety-insomnia cycle), and relaxation training. Fully automated digital CBT-I programs now show significant effects across 29 clinical trials, making this treatment accessible without a therapist ^[5].

Exercise as a sleep intervention

Regular physical activity is one of the most effective non-pharmacological treatments for insomnia. A 2024 systematic review of 19 studies confirmed significant improvements in both objective and subjective sleep parameters ^[6]. Moderate aerobic exercise, yoga, tai chi, and walking or jogging are particularly effective. The optimal dose appears to be 30 minutes, three times per week, for at least eight weeks. Timing matters: avoid high-intensity training within an hour of bedtime, as it can delay sleep onset.

Supplements and sleep

Magnesium bisglycinate is the most evidence-backed supplement for insomnia. A randomized placebo-controlled trial showed a statistically significant reduction in insomnia severity scores, with most improvement occurring within the first 14 days ^[7]. Melatonin (0.5-3 mg) can help with circadian rhythm issues like jet lag or shift work, but it's not a general-purpose sleep aid. Valerian, passionflower, and L-theanine have some supporting evidence, though effect sizes are generally smaller than CBT-I or exercise. Prescription sleep medications carry dependency risks and don't address root causes, which is why guidelines recommend them only for short-term use.