2026-02-24
Testosterone Decline in Men: Natural Trajectory, Functional Impact, and Evidence-Based Support
Testosterone declines approximately 1-2% per year from age 30. The clinical significance of this decline depends on absolute levels and symptoms, not chronological age alone. Testosterone replacement therapy has RCT evidence for improving muscle mass, bone density, and sexual function in men with confirmed hypogonadism. Lifestyle factors significantly modify the trajectory.
2026-02-24
Circadian Rhythm Disruption in Aging: Mechanisms, Health Consequences, and Restoration
Circadian clocks govern virtually every physiological process — metabolism, immune function, DNA repair, and hormone secretion follow 24-hour rhythms entrained by light. With aging, the circadian system weakens: clock gene amplitude declines, light sensitivity decreases, and circadian outputs desynchronize. Strengthening circadian inputs through light exposure, meal timing, and physical activity has evidence-based effects on sleep, metabolic health, and biological aging.
2026-02-24
Sleep Architecture in Aging: Why Deep Sleep Declines and How to Partially Restore It
Slow-wave sleep (deep sleep) declines approximately 2% per decade from early adulthood, dropping from roughly 20% of total sleep in young adults to under 5% in adults over 70. This decline is not simply reduced sleep duration — it represents a fundamental change in sleep architecture with consequences for metabolic health, memory consolidation, and cellular repair.
2026-02-24
Alcohol, Aging, and Long-Term Health: What the Evidence Shows
Alcohol consumption interacts with aging biology in complex ways. This article covers the liver, brain, cardiovascular, and cancer evidence, plus what nutritional strategies can mitigate harm.
2026-02-24
Blue Zone Dietary Patterns: What the Longest-Lived Populations Actually Eat
Blue Zone populations (Sardinia, Okinawa, Nicoya, Ikaria, Loma Linda) share dietary patterns centered on whole plant foods, moderate caloric density, and minimal ultra-processed food. Epidemiological data consistently associates these patterns with lower all-cause mortality, though confounding by lifestyle, social, and genetic factors limits causal inference.