An estimated 57 million people around the world are living with dementia, and that number is expected to increase to 153 million by 2050.
But a new report published by the Lancet Commission on dementia estimates that almost half of the cases of the neurological disease can likely be avoided or delayed. Twenty-seven of the world’s leading dementia experts co-authored the report.
These experts point to 12 existing risk factors and two new ones that could prevent or delay dementia.
The two new risk factors included are vision loss and having high low-density lipoprotein or LDL cholesterol.
The previous 12 risk factors include less education, hearing loss, depression, traumatic brain injury, physical inactivity, smoking, diabetes, hypertension, obesity, excessive alcohol consumption, social isolation, and air pollution.
Some of these risk factors play a greater contributing role in early life rather than late life. For example, having less education is a more prominent risk factor in early life. Risk factors like social isolation, air pollution, and untreated vision loss are greater risk factors in late life, while the other risk factors pose a greater risk in midlife.
“In short, these factors put a person at higher or lower risk of developing dementia,” Carol Brayne, professor of public health medicine at the University of Cambridge, and her doctoral student Seb Walsh told The Epoch Times over email.
“That means that you cannot say to an individual person, if you stop smoking, or if you get your blood pressure under control, then you definitely won’t get dementia. But if we do this for many people across society then we expect some reduction in dementia prevalence across age groups, even though not ‘preventing’ it entirely.”
14 Risk Factors
The risk factors were determined from data from 37,000 participants aged 45 and older who participated in the Norwegian HUNT study. The Commission looked at evidence from the data and other reviews to decide what factors were most likely associated with dementia.
Specifically, new evidence supports vision loss and high cholesterol as new modifiable risk factors for dementia, the report notes.
The initial 12 risk factors were linked with 40 percent of cases, but the new report notes that addressing all 14 factors could prevent or delay 45 percent of dementia cases.
The report did not assess the number of years dementia may be delayed if a person reduces their risk factors.
“Dementia increases exponentially with age. So we are generally talking about a population where, if you delay its onset by a few years, some will die of other things in the meantime and dementia will effectively be ‘prevented’ for that person. For others, they will still develop dementia but later in their life and closer to death,” said Brayne and Walsh.
In particular, the report found that high LDL cholesterol and hearing loss had the greatest weighting in their link to dementia. The two factors were attributed to around a third of preventable dementia cases.
Less education in early life was associated with 11 percent of all preventable cases, leading to a call for good quality education and “cognitively stimulating activities in midlife to protect cognition” by the Commission.
For those risk factors that occurred during midlife, depression and traumatic brain injury comprised 6 percent of preventable cases respectively, and physical inactivity, smoking, diabetes, hypertension, and obesity were all associated with 2 to 4 percent of preventable cases.
Among all risk factors, depression in midlife had the lowest prevalence but made up a significant proportion of preventable dementia cases.
“Depression is both risk and early symptom as well as often being present during dementia progression until moderate stages. So it’s a particularly challenging risk to examine and many studies look earlier in life to try and tease out the risk factor element specifically to make sure it is a risk not a prodrome,” Brayne and Walsh said.
For cases affecting older individuals, social isolation was associated with around 10 percent of preventable cases, while air pollution was associated with 5 percent.
The Commission noted that prevention should be “ambitious.” “Prevention involves both policy changes at national and international governmental levels and individually tailored interventions.”
The Commission recommended specific actions to reduce dementia risk across one’s life. They include:
- Having good quality education and engage in cognitively stimulating activities in mid-life
- Using hearing aids and reducing harmful noise exposure, for those with hearing loss
- Treating depression
- Using helmets and head protection in contact sports and when riding
- Exercising
- Reducing smoking
- Preventing or reducing hypertension
- Detecting and treating high LDL cholesterol from midlife
- Maintaining a healthy weight and treating obesity as early as possible; this can also help to prevent diabetes
- Reducing high alcohol consumption
- Prioritizing age-friendly and supportive community environments and housing
- Reducing social isolation by facilitating participation in activities and living with others
- Making screening and treatment for vision loss accessible
Will tackling all risk factors completely ameliorate dementia cases?
“Some people will still develop dementia,” Professor Gill Livington said in an interview with The Epoch Times. “We expect those that do to have a longer life span of which they are healthy and a shorter time with dementia at the end of their life.”
