Caffeine

Caffeine is a central nervous system stimulant that primarily acts by antagonizing adenosine receptors, which promotes wakefulness and alertness. Its healthspan relevance stems from large observational studies linking regular consumption (primarily from coffee and tea) with reduced risk for all-cause mortality, cardiovascular disease, neurodegenerative diseases, and certain cancers.

Verdict

A well-evidenced, low-cost habit for alertness and potentially lower mortality risk.

Protocol

• Consume 100-400mg daily, primarily in the morning to avoid sleep disruption.
• Cycle off caffeine periodically (e.g., one week per month) to reset tolerance.

Flags

• Can significantly disrupt sleep architecture; avoid consumption within 8-10 hours of bedtime.
• Individuals with 'slow metabolizer' CYP1A2 gene variants may have increased cardiovascular risk.
• High doses can induce anxiety, palpitations, and gastrointestinal distress.
• Can interact with certain medications, including some antibiotics and antidepressants.
• Abrupt cessation can lead to withdrawal symptoms like headaches and irritability.