Age-Related Illness – Part 2.7 of a 7 Part Series

Age-Related Illness – Part 2.7 of a 7 Part Series

Welcome back to our ‘Physiological Need for Light’ series! Today, we look about a connection between light and the age-related illnesses, Alzheimer’s.


  • Individuals with Alzheimer’s and Related Dementia [ADRD] often sleep during the day and are awake at night

  • Night time wandering causes burdens on caretakers

  • ADRD individuals experience lower light levels, exhibit lower activity levels and had greater disruption of their natural circadian rhythms compared to healthy older adults


  • LRC performed the first field study to examine the synchrony between the circadian light pattern and the activity response pattern to assess circadian disruption

  • Circadian rhythms are governed by the human body’s master clock in the Suprachiasmatic nuclei [SCN]

  • The retina synchronizes the SCN to the 24 hour solar day

  • Physicians will soon be able to predict the optimum timing of light therapy to re-sync the circadian phase with the solar day

  • Treatment could include going outdoors for 15 minutes and sitting in front of a light box fitted with blue LEDs for a prescribed amount of time

  • Exposure to blue LEDs for 30 minutes during the morning hours (between 8:00 and 11:00am) improves nighttime sleep, daytime wakefulness, and motor restlessness in ADRD patients


Join us next time in the Physiological Need for Light series as we discuss a device used to record light and activity levels!