Article body
The World Health Organization (WHO) has released a major update to its guidelines on reducing the risk of cognitive decline and dementia. The second edition of the original 2019 report was updated to "reflect the latest evidence and advances in dementia risk reduction." The following seven additional health conditions and exposures were added to the list.
Menopausal hormone therapy (MHT) is one of the new risk factors. The WHO does not recommend menopausal hormone therapy specifically to prevent dementia in postmenopausal women 65 and older. For younger women, it says there is not enough evidence to determine whether MHT affects dementia risk. Stroke and traumatic brain injury (TBI) are also highlighted as significant risk factors. TBI can range from a mild concussion to a severe brain injury, and conditions that affect the heart and blood vessels can also affect brain health.
Vision impairment and sleep disorders have been linked to cognitive decline as well. The WHO notes that while vision impairment may place additional demands on the brain, there is insufficient evidence to recommend vision treatment specifically for dementia prevention. Sleep challenges affect tens of millions of Americans, and research suggests that sleep may help the brain clear beta-amyloid, although the relationship between sleep and dementia remains complex. HIV and air pollution are also recognized as risk factors, with untreated HIV affecting the central nervous system and air pollution linked to a higher risk of cognitive decline. These updates emphasize the importance of lifestyle changes for dementia prevention.