By Eric B. Larson and Laura Gitlin
Nearly half of all dementia cases could be delayed or prevented altogether by addressing 14 possible risk factors, including vision loss and high cholesterol.
That is the key finding of a new study that we and our colleagues published in the journal The Lancet.
Dementia, a rapidly increasing global challenge, affects an estimated 57 million worldwide, and this number is expected to increase to 153 million by 2050 worldwide. Although the prevalence of dementia is on the decline in high-income countries, it continues to increase in low- and middle-income countries.
This third updated report of the Lancet Commission on Dementia offers good news and a strong message: Policymakers, clinicians, individuals and families can be ambitious about prevention and reduce dementia risk; and for those living with dementia and their caregivers, support their quality of life using evidence-based approaches.
The new report confirms 12 previously identified potentially modifiable risk factors from two previous reports, published in 2017 and 2020. It also offers new evidence supporting two additional modifiable risk factors: vision loss and high levels of low-density lipoprotein (LDL) cholesterol, often called “bad” cholesterol.
Our study of published evidence found that collectively, addressing 14 modifiable risk factors could potentially reduce the prevalence of dementia by 45% worldwide. Even greater risk reductions could be possible in low- and middle-income countries and for people with low income in higher-income countries given the higher prevalence of dementia, health disparities and risk factors in these populations.
The report further indicates that reducing these 14 risks can increase the number of healthy years of life and reduce the length of time with poor health in people with dementia.
Additionally, the report cites clinical trials showing that nonpharmacological approaches, such as using activities tailored to interests and abilities, can reduce dementia-related symptoms and improve quality of life.
We are a general internist and an applied sociologist and intervention scientist, and our work focuses on memory and wellness in older adults. Together with 25 other internationally recognized dementia experts under the leadership of psychiatry professor Dr. Gill Livingston, we carefully reviewed the evidence to derive recommendations for prevention, intervention and care.
Why it matters
The rapid growth of aging populations worldwide is a triumph of better public and personal health throughout the entire life span. Yet, given the lack of a dementia cure, this report highlights the importance of prevention as well as supporting quality of life for those with a dementia diagnosis.
In the new report, our team proposed an ambitious program for preventing dementia that could be implemented at the individual, community and policy levels and across the life span from early life through mid and late life. The key points include:
- In early life, improving general education.
- In midlife, addressing hearing loss, high LDL cholesterol, depression, traumatic brain injury, physical inactivity, diabetes, smoking, hypertension, obesity and excessive alcohol.
- In later life, reducing social isolation, air pollution and vision loss.
AlexRaths/iStock via Getty Images Plus
Together, these add up to the Lancet Commission on Dementia’s estimate that 45% of dementia risk can be reduced. And an abundance of new research shows that when risk factors are addressed, such as exposure to air pollution, they are linked with improved cognition and likely reduction of dementia risk.
New evidence supports the notion that in high-income countries, reducing dementia risk can translate to more healthy years, years free of dementia and a shorter duration of ill health for people who develop dementia.
What still isn’t known
The 45% reduction in dementia risk across the world’s population is based on a calculation that assumes that risk factors are causal and can be eliminated. It shows how dementia prevention is critical and the impact it would have on individuals and families.
The commission emphasized the need for more research to identify additional risk factors, test risk factor changes in clinical trials, provide guidance for public health efforts, and identify and evaluate strategies for implementing and scaling evidence-based programs that support people with dementia and caregivers.
The updated report has worldwide public health and research impact and is being widely disseminated. It serves as a guideline to clinicians and policymakers and outlines new research directions.
Eric B. Larson is Affiliate Professor of Medicine at the University of Washington School of Medicine. Laura Gitlin is Dean Emerita and Distinguished Professor of Nursing and Health at Drexel University.
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DaleL says
The reduction of dementia by 45% is a bold claim. “The 45% reduction in dementia risk across the world’s population is based on a calculation that assumes that risk factors are causal….” There is the rub. The “risk factors” are associations with dementia. For example, hearing loss is associated with an increased risk of dementia according to this story. “…hearing loss is an important and modifiable feature of mid- and later-life aging that can hasten brain decline.” Or perhaps, brain decline can cause hearing loss.
Association is not causation.
I take stories like this with more than a bit of skepticism. Generally, moderation in all things is best.
Ray W. says
Hello DaleL. Thank you.
I argue that every last FlaglerLive reader should be skeptical of anything I post. Skepticism is the foundation of science, the foundation of learning.
For the record, again, I am not bothered if Ed P disagrees with me. I want him to disagree with me. I want someone, anyone, to take up the mantle of the reasoned conservative voice on these pages. There are only so many windmills against which anyone can tilt, and we all need more reasoned voices.
I choose to tilt against the malicious among us, the murderous among us, the deceivers among us, the “pestilential” partisan members of faction among us. Right now, that seems to be the many Republican FlaglerLive commenters who can’t accept that they are no longer conservative. Theirs has become a party of division and hate, or king-worship and obedience.
When will it be time to start beheading Democrats? a local so-called conservative asked. I alone can fix things, a national so-called conservative claimed. Conservatism is not an idea based on murder and violence. Conservatism is not an idea that kings or tyrants should rule.
Once again, as many times as it takes, the history of the conservative movement begins with the Glorious Revolution of 1687.
King James II asserted that as king, England’s Parliament had to bow to his wishes; he alone ruled England. Parliament, controlling the public purse, raised an army and stood up to the king, who fled the country.
Under the religious beliefs of that time (God was the ship’s captain, not the ship’s builder), Parliament reached out to Netherland’s royalty and selected William to become England’s king, but only if he agreed to respect Parliament’s powers. After all, God created kings to rule and protect the people. The people could not rule themselves; it was agreed. As king, William would have limited powers, and Parliament would hold other limited powers. That parliament firmly established the idea of “separation of powers.” It then adopted a 13-point Bill of Rights.
Yes, conservatism, as an idea, began with the foundations of honoring the rule of law, respect for individual rights, and a separation of limited powers between the executive branch (king) and the legislative branch (parliament). The legislature, under conservation thought, never cedes power to the executive.
As an aside, I apologize to all FlaglerLive readers. I previously argued that parliament selected the Hanoverian George to become king. That was, obviously, my oft-faulty memory. I looked it up. William, married to Mary, was the Dutch royal member who replaced James. When William died, Mary became Queen. When she died, a dispute over lineage arose. George was chosen to become king.
Oy, vey!
Toxic babies says
More likely plastic consumption. Micro plastics can move freely through your organs. It’s already in all of us and just accumulating. Poisoned the world for convenience. No solution but more regulation can reduce.