After one short night, older and younger brains shifted in opposite directions
Researchers at Simon Fraser University scanned adults aged 20 to 30 and adults aged 65 to 75 after a normal night and after a night limited to three hours of sleep. Brain-region coordination rose in the younger group and fell in the older group, a short-term experimental finding about brain-network patterns that does not show better memory or everyday performance after lost sleep. Source: Knowridge — https://knowridge.com/2026/10/sleep-loss-affects-older-and-younger-brains-in-opposite-ways/
Heavy use of low-calorie sweeteners tracked with quicker thinking decline before age 60
In a long-running observational study of 12,772 Brazilian adults, published in Neurology, people under 60 who consumed more low- or no-calorie sweeteners showed faster declines in overall thinking and word-finding scores over about eight years. Six of seven sweeteners examined showed this link individually, while tagatose did not, but the observational design cannot prove the sweeteners caused the change. Source: Knowridge — https://knowridge.com/2026/11/six-common-sugar-substitutes-linked-to-faster-memory-and-thinking-decline/
Extra thyroid hormone in later life tied to higher chance of a thinking-disorder diagnosis
Johns Hopkins researchers reviewed records for 65,931 adults aged 65 and older seen in primary care between 2014 and 2023, in a study published in JAMA Internal Medicine. Excess thyroid hormone, whether from thyroid disease or from replacement treatment, was linked to a 39% higher relative risk of a later mild cognitive impairment or dementia diagnosis, with an estimated 11% affected by age 75 versus 6.4% without such exposure; as a records study, it cannot prove causation. Source: Knowridge — https://knowridge.com/2026/11/excess-thyroid-hormone-linked-to-higher-dementia-risk-in-older-adults/