A large study of 87,577 adults followed for over 8 years found that people who received more bright light during the day had a lower risk of developing dementia over time. The researchers used wrist-worn devices to objectively measure both daytime and nighttime light exposure, not just self-reported “time outside.”

At BrainSavers, we know sleep is a cornerstone of brain+body fitness. It sharpens memory, stabilizes mood, boosts focus, and protects against cognitive decline as we age. Yet sleep deficiency is all too common — and preventable. Sleep deficiency occurs when you get too little sleep, sleep at irregular times, experience poor-quality sleep, or have an untreated sleep disorder. It is not just about feeling groggy; it impairs daily function and raises risks for serious health is

Irregular sleep was not good in any study Among all the studies reviewed, irregular sleep was either neutral or harmful; none showed that irregular sleep was good for health or performance In some long‑term studies, each extra hour of fluctuation in sleep timing was linked to notably higher risk of metabolic syndrome and heart events.