07.08.2024 - "We can prevent or delay nearly half of dementia cases by addressing 14 risk factors from childhood and throughout life. This includes two new risk factors: high cholesterol and vision loss," says Geir Selbæk, research director at the National Center for Aging and Health.
This is the latest report from the Lancet Commission on the prevention, treatment, and care of dementia. Selbæk is one of 27 members of this highly respected commission. He contributed to the report, which was presented at the Alzheimer’s Association International Conference (AAIC 2024) in Philadelphia, USA, this week.
"The potential to prevent and better manage dementia is significant, even for people with a high genetic risk for the disease," he says.
"And this is true even though people worldwide are living longer and the number of people with dementia is expected to increase drastically."
High cholesterol and vision loss are added to the 12 risk factors identified by the Lancet Commission in 2020: low education level, hearing loss, high blood pressure, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol consumption, severe brain injury, high air pollution, and social isolation.
The new report estimates that the four most important risk factors for dementia are hearing loss, high cholesterol, low education early in life, and social isolation later in life.
The commission urges governments and individuals to be ambitious in managing dementia risk throughout life.
"The earlier we can address and reduce risk factors, the better. The report outlines a new approach to policy and lifestyle changes to help prevent, delay, and better manage dementia," says Selbæk.
He believes more action is needed to reduce dementia risk worldwide. Due to the rapidly aging population, the number of people living with dementia is expected to nearly triple by 2050, rising from 57 million in 2019 to 153 million.
"In Norway, according to the Dementia Map, we will see more than a doubling of dementia cases around 2050," says Selbæk.
In some high-income countries, including the USA and the UK, the proportion of older people with dementia has actually fallen, especially among those living in socioeconomically advantaged areas.
"This decline in the proportion of people developing dementia is likely due to building cognitive and physical resilience throughout life. There is less damage due to improvements in healthcare services and lifestyle changes. This highlights the importance of implementing preventive approaches as early as possible," says Selbæk.
"We see some of the same trends in Norway. However, most national dementia plans, including Norway's, do not have clear recommendations on what we can do to reduce the risk of dementia," he says.
Never too late to reduce dementia risk "Our new report reveals that much more can and should be done to reduce the risk of dementia. It is never too early or too late to take action, with opportunities to make a difference at all stages of life," says the leader of the Lancet Commission, Professor Gill Livingston from the UK.
"We now have stronger evidence to say that longer exposure to risk increases the chance of dementia, and that the risk has a stronger impact on people who are already vulnerable. It is therefore crucial to increase preventive efforts towards those who need it most, including people in socioeconomically disadvantaged groups and in low- and middle-income countries. Governments must reduce dementia risk by making a healthy lifestyle as achievable as possible for everyone."
To reduce dementia risk, the commission presents 13 recommendations to governments and individuals:
1. Ensure high-quality education is available to all and encourage cognitively stimulating activities in midlife.
2. Make hearing aids available for people with hearing loss and reduce harmful noise exposure.
3. Treat depression effectively.
4. Encourage the use of helmets and head protection in contact sports and cycling.
5. Promote physical activity as people who participate in sports and exercise are less likely to develop dementia.
6. Reduce smoking through education, price regulation, and banning smoking in public places, and make cessation advice available.
7. Prevent or reduce high blood pressure from the age of 40.
8. Detect and treat high cholesterol in midlife.
9. Maintain a healthy weight and treat obesity as early as possible, which also helps prevent diabetes.
10. Reduce high alcohol consumption through price regulation and increased awareness of the risks of overuse.
11. Prioritize age-friendly communities, and reduce social isolation by facilitating participation in activities and co-living.
12. Make screening and treatment for vision loss available to everyone.
13. Reduce exposure to air pollution.
"These measures are especially important given new research showing that reducing dementia risk not only increases the number of years with good health but also reduces the time people with dementia spend in poor health," says Selbæk.
Professor Livingston elaborates:
"A healthy lifestyle, which includes regular exercise, non-smoking, cognitive activity in midlife (even outside formal education), and avoiding excessive alcohol use, can not only reduce dementia risk but also delay the onset of dementia. So, if people develop dementia, they are likely to live fewer years with the disease. This could mean a great deal for the quality of life of individuals as well as significant cost savings for society," she says.
Focus on alcohol consumption
Consumption of alcohol at the rate of more than 21 units per week in mid-life (age 45–64 years) is estimated to increase the risk of dementia by around 7%. Following the 2018 imposition of a minimum price of alcohol of £0.5 per unit in Scotland, alcohol consumption reduced by 1.2 units per week per adult, with a particular reduction in those in the most deprived areas. The policy appears to have led to no cost to the alcohol industry and no statistically significant change in moderate drinking (only heavy drinking), and retailers appear to have complied with the policy. There were no estimates of enforcement or monitoring costs of this policy, so they were not included in the model.
In England, the proportion of adults aged 45–64 years who drink more than 21 units of alcohol per week is 19%. Introducing a minimum price per unit of alcohol in England would be expected to result in 4767 quality-adjusted life years (QALYs) gained and a cost-saving of £280 million. The effect of a price rise for the minimum price of alcohol intervention depends on the price elasticity of demand or how sensitive the quantity demanded is to the price, with higher numbers indicating greater sensitivity to price. For example, if a price rise of 10% causes demand to fall by 5%, the price elasticity would be –0.50. A review of the evidence by NHS Scotland indicates an elasticity of –0.50 or –0.35 in people who drink heavily. A 10% increase in the price of alcohol with an elasticity of –0.35 would result in estimated cost-savings in England of £172 million with 2934 QALYs gained.
According to a new report, a country like England could achieve cost savings of around 4 billion pounds if it follows these recommendations.
"There is no reason to believe that Norway differs significantly from the UK," says Selbæk.
Reference
Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission
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