More than 57 million people worldwide living with dementia

• The World Health Organisation (WHO) has issued updated global guidelines aimed at reducing the risk of cognitive decline and dementia, saying that up to 45 per cent of cases may be preventable or delayed by addressing modifiable risk factors throughout life.

Key points on dementia:

• Dementia is a condition caused by brain diseases and affects memory, thinking and the ability to function. 

• More than 57 million people worldwide are living with dementia, with nearly 10 million new cases diagnosed each year. 

• Dementia gets worse over time. Although more common after age 65, it is not an inevitable part of ageing.

• Dementia can be caused by several diseases which over time damage the brain, typically leading to deterioration in cognitive function beyond what might be expected from the usual consequences of biological ageing. 

• The impairment in cognitive function is commonly accompanied, and occasionally preceded, by changes in mood, emotional control, behaviour or motivation.

• Dementia has physical, psychological, social and economic impacts, not only for people living with dementia, but also for their carers, families and society at large. 

• Alzheimer’s disease accounts for an estimated 60 to 70 per cent of all dementia cases.

• Other forms include vascular dementia, dementia with Lewy bodies (abnormal deposits of protein inside nerve cells), and a group of diseases that contribute to frontotemporal dementia (degeneration of the frontal lobe of the brain).

• Dementia may also develop after a stroke, in the context of certain infections such as HIV, as a result of harmful use of alcohol, after repeated injuries to the brain, or because of nutritional deficiencies.

• While there is no cure for dementia, up to 45 per cent of the risks can be attributed to modifiable risk factors such as tobacco, alcohol use, social isolation, physical inactivity, air pollution and noncommunicable diseases (NCDs), including high blood pressure and diabetes. 

Human and economic cost

• Beyond memory loss and cognitive impairment, dementia can undermine a person’s independence, dignity and safety while placing heavy emotional and financial burdens on families and caregivers.

• WHO estimates dementia costs the global economy around $1.3 trillion each year, with roughly half of that burden stemming from unpaid care provided by family members and friends.

• The agency said integrating dementia prevention into services for noncommunicable diseases, mental health and brain health could help reduce the global burden of the condition and enable more people to live longer, healthier and more independent lives.

Highlights of updated guidelines

• The new guidance updates WHO’s 2019 recommendations and reflects the latest evidence on preventing cognitive decline across the life course.

It recommends:

• Regular physical activity.

• Stopping tobacco use.

• Reducing alcohol consumption.

• Eating a healthy diet.

• It also highlights the importance of cognitive training, social engagement and managing conditions such as high blood pressure, diabetes and high cholesterol.

• For the first time, WHO also recommends reducing exposure to air pollution as part of dementia prevention strategies. 

• The use of hearing aids may also help lower dementia risk in some people.

• However, WHO advises against taking vitamin B or E supplements, omega-3 fatty acids or multivitamins solely to prevent dementia unless a deficiency has been diagnosed, citing insufficient evidence that the supplements provide benefits that outweigh potential harms.