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.

1. Stroke
2. Traumatic brain injury
3. Vision impairment
4. Sleep problems
5. HIV
6. Air pollution
7. Menopausal hormone therapy

These new risk factors joined the previously existing 12, which are listed below.

1. Cognitive activity
2. Social activity
3. Physical inactivity
4. Harmful alcohol use
5. Tobacco use
6. Unhealthy diet/nutrition
7. Obesity
8. Diabetes
9. Hypertension
10. Dyslipidemia (abnormal amount of lipids (fats) or lipoproteins in the blood)
11. Hearing loss
12. Depression

Dr. Daniel Amen, physician and founder of Amen Clinics in California, has his own formula for reducing Alzheimer’s risk factors, following an acronym called BRIGHT MINDS.

This stands for blood flow, retirement and aging, inflammation, genetics, head trauma, toxins, mental health, immunity and infections, neurohormones, diabesity (co-occurrence of obesity and type 2 diabetes) and sleep. The WHO’s updated guidelines offer similar advice.

Amen spoke with Fox News Digital about the new additions to the WHO’s list of risk factors.

Menopausal hormone therapy (MHT)

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.

Amen agreed that there is not enough evidence to support using MHT specifically to prevent dementia. He said hormonal changes during menopause may affect mood and memory, although the relationship between MHT and dementia risk remains uncertain.

“For women, as they go through menopause, lower progesterone makes them anxious, and [with] lower estrogen, they start to have memory problems,” he said. “Hormone replacement early on is helpful, and that’s what we see on the brain imaging work that we do.”

Experts note that while menopause-related hormonal changes can be associated with mood and cognitive symptoms, these effects can vary widely.

Stroke

A stroke occurs when blood flow to part of the brain is blocked or when a blood vessel in or near the brain bursts, according to the American Stroke Association.

Conditions that affect the heart and blood vessels can also affect brain health and are associated with a higher risk of dementia, according to Amen.

That can include conditions such as heart disease, heart rhythm problems, stroke and transient ischemic attacks. Erectile dysfunction can also be associated with underlying vascular disease, he said.

“And 40% of 40-year-olds have erectile dysfunction, 70% of 70-year-olds. So, if I’m an older person, I’m thinking if I get my brain right, my love life could be better, too,” Amen added.

Traumatic brain injury (TBI)

Amen surmised that the WHO is “late to the party” in emphasizing the importance of head trauma as a dementia risk factor. TBI can range from a mild concussion to a severe brain injury.

“One of the big lessons from the brain imaging work we do is that mild traumatic brain injury ruins people’s lives,” he said. “They end up seeing psychiatrists because they have temper problems or … depression or anxiety, and it’s really from a snowmobiling accident in [their] 30s.”

Amen added that failing to protect the brain — which he described as “very soft” and having the consistency of “soft butter” — is “not the smart thing to do.”

Vision impairment

A significant portion of the brain is dedicated to vision, according to Amen.

“So, if your vision becomes troubled, your brain’s troubled,” he said.

Amen said vision impairment may place additional demands on the brain. While the condition has been linked with cognitive decline, the WHO says there is insufficient evidence to recommend vision treatment specifically for dementia prevention.

Sleep disorders

Sleep appears to support the brain’s waste-clearance processes, Amen noted.

Sleep challenges affect tens of millions of Americans. In 2024, 30.5% of U.S. adults reported getting less than seven hours of shut-eye per day, according to the CDC.

For those with sleep problems such as sleep apnea, it can cause changes in the brain that resemble the hallmarks of Alzheimer’s disease, the expert said.

Research suggests that sleep may help the brain clear beta-amyloid, although the relationship between sleep and dementia remains complex and is still being studied.

HIV

Inflammation and infections can affect brain health. Untreated HIV (human immunodeficiency virus) can affect the central nervous system and is associated with HIV-related cognitive impairment.

Amen said he has scanned “hundreds of people” with HIV, stating that the virus is “clearly a risk factor.”

Untreated HIV is known to affect the central nervous system and is associated with HIV-related cognitive impairment. Effective antiretroviral therapy has greatly reduced the incidence of severe HIV-associated dementia.

Air pollution

Exposure to any toxins, from alcohol and marijuana to lead, mercury or air pollution, could be detrimental to brain health, according to Amen.

The WHO recommends reducing exposure to household and outdoor air pollution, particularly fine particulate matter. Research has linked long-term exposure to air pollution with a higher risk of cognitive decline and dementia, although the WHO characterizes the evidence as low to very low certainty.

Getting ahead of it

Dementia risk rises sharply with age. A recent U.S. analysis estimated that about one in five people had developed dementia by age 85, with risk increasing further at older ages.

While those with a genetic predisposition to the disease have a higher risk, Amen noted that certain lifestyle factors can increase the risk for anyone.

“We should be on a dementia prevention program our whole lives,” the doctor said. “It’s not something to start when you’re 65.”

Amen urged everyone to ask themselves the question: “Is what I’m doing good or bad for my brain?”

“Social activity is one of the prevention strategies. New learning is a prevention strategy,” he added. “So always working on being connected with other people and then just making better decisions.”

“If you love and care for your brain, you’re going to love your life a whole bunch more.”