The World Health Organization (WHO) has updated its guidelines on reducing the risk of cognitive decline and dementia, adding seven new health conditions and exposures to its list. The revisions, which form the second edition of the organization's original 2019 report, aim to incorporate the most recent scientific evidence and advancements in dementia risk reduction.
Among the newly identified risk factors are stroke, traumatic brain injury (TBI), vision impairment, sleep problems, HIV, air pollution, and menopausal hormone therapy. These additions join the 12 previously recognized risk factors, which include cognitive activity, social activity, physical inactivity, harmful alcohol use, tobacco use, unhealthy diet, obesity, diabetes, hypertension, dyslipidemia, hearing loss, and depression.
Dr. Daniel Amen, a physician and founder of Amen Clinics, noted that many of these factors align with his own BRIGHT MINDS formula for reducing Alzheimer's risk, which emphasizes blood flow, inflammation, genetics, head trauma, toxins, mental health, immunity, neurohormones, diabesity, and sleep. While the WHO does not specifically recommend menopausal hormone therapy (MHT) for dementia prevention, it acknowledges that hormonal changes during menopause can affect mood and memory. Amen suggested that early hormone replacement may be beneficial, although the direct link between MHT and dementia risk remains uncertain.
Stroke, defined as a disruption of blood flow to the brain or a ruptured blood vessel, is highlighted as a significant risk factor. Conditions affecting cardiovascular health, such as heart disease and irregular heart rhythms, can also impact brain health and increase dementia risk. Amen pointed out a correlation between erectile dysfunction and underlying vascular disease, suggesting that addressing brain health could also benefit sexual health.
Traumatic brain injury, ranging from mild concussions to severe injuries, is also emphasized. Amen stated that even mild TBIs can lead to long-term issues like mood disturbances and depression, underscoring the importance of protecting the brain.
Vision impairment is recognized as a factor, with a significant portion of the brain dedicated to processing visual information. While linked to cognitive decline, the WHO indicates insufficient evidence to support vision treatment specifically for dementia prevention. Sleep disorders, affecting millions of Americans, are also included. Research suggests that sleep may play a role in the brain's waste-clearing processes, and conditions like sleep apnea can lead to brain changes similar to those seen in Alzheimer's disease.
Inflammation and infections, such as untreated HIV, can impact the central nervous system and are associated with cognitive impairment. However, effective antiretroviral therapy has significantly reduced the incidence of severe HIV-associated dementia.
Exposure to toxins, including air pollution, is also a concern. The WHO recommends reducing exposure to household and outdoor air pollution, as studies have linked long-term exposure to an increased risk of cognitive decline, though the certainty of this evidence is characterized as low to very low.
Dementia risk increases significantly with age, with estimates suggesting a considerable portion of individuals develop it by age 85. While genetics play a role, lifestyle factors are crucial for everyone. Amen advocates for a lifelong approach to dementia prevention, emphasizing the importance of social engagement, continuous learning, and making brain-healthy choices.