Written by Timothy Huzar — Fact checked by Hilary Guite, FFPH, MRCGP
The study, which features in the Journal of Neurology, Neurosurgery and Psychiatry, provides further information for scientists to boost their understanding of the complex causes of dementia.
According to the Centers for Disease Control and Prevention (CDC), dementia describes a number of disorders that cause a person to develop cognitive issues.
The most common type of dementia is Alzheimer’s disease — a neurodegenerative illness that typically affects older people. About 5.8 million people in the United States had Alzheimer’s disease in 2020.
By 2060, the CDC estimates that this number is likely to increase to 14 million people.
Alzheimer’s disease begins with mild symptoms, such as a worsening memory. Some people may assume that this symptom is a natural part of aging, as not all memory loss is due to dementia. However, if the disease progresses, it can become severe, leaving people unable to recognize close friends or family or to care for themselves.
There is no known cure for Alzheimer’s disease. Scientists believe that a combination of genetic, behavioral, and environmental factors is responsible for the condition. As such, clinicians focus on preventing people from developing the disease and helping them manage its symptoms.
The World Health Organization (WHO) has called for a greater commitment from governments around the world to tackle dementias such as Alzheimer’s disease.
Dr. Tedros Adhanom Ghebreyesus — Director-General of the WHO — says, “Dementia robs millions of people of their memories, independence, and dignity, but it also robs the rest of us of the people we know and love.”
“The world is failing people with dementia, and that hurts all of us. Four years ago, governments agreed a clear set of targets to improve dementia care. But targets alone are not enough. We need concerted action to ensure that all people with dementia are able to live with the support and dignity they deserve,” Dr. Ghebreyesus points out.
In the present study, the researchers wanted to get more information on the effects of potentially modifiable lifestyle factors on a person’s dementia risk — particularly for people with a genetic predisposition to dementia.
The researchers focused on a person’s level of frailty. Frailty describes a range of health issues and may be useful in helping clinicians determine whether a person has dementia or is likely to develop it.
The scientists drew on data from the UK Biobank, a large-scale genetic and health database in the United Kingdom.
They used data from 196,123 people, looking at each participant’s genetic risk of dementia, frailty, and healthy lifestyle behaviors. They then checked which individuals developed dementia over a 10-year period.
These people were a subset of the UK Biobank’s participants, who number more than 500,000. The researchers only included those over the age of 60 years at baseline who had no dementia and had complete data available on their risks of dementia and frailty.
During the study period, 1,762 participants developed dementia. The researchers found that these participants were more likely to have a greater level of frailty than people who did not develop dementia.
The most frail participants were 3.68 times as likely to develop dementia compared with the least frail participants, independent of genetic risk.
The researchers also found that frailty increased the risk of dementia even for people already genetically predisposed to develop the condition.
Lead author Dr. David Ward, from the Division of Geriatric Medicine at Dalhousie University, Nova Scotia, Canada, says that “
e’re seeing increasing evidence that taking meaningful action during life can significantly reduce dementia risk.”
“Our research is a major step forward in understanding how reducing frailty could help to dramatically improve a person’s chances of avoiding dementia, regardless of their genetic predisposition to the condition,” he adds.
“This is exciting because we believe that some of the underlying causes of frailty are in themselves preventable. In our study, this looked to be possible partly through engaging in healthy lifestyle behaviors.”
Co-author Dr. Janice Ranson, from the University of Exeter Medical School, U.K., says that “[t]hese findings have extremely positive implications, showing it’s not the case that dementia is inevitable, even if you’re at a high genetic risk.”
According to her, “
e can take meaningful action to reduce our risk; tackling frailty could be an effective strategy to maintaining brain health, as well as helping people stay mobile and independent for longer in later life.”
Speaking with Medical News Today, Dr. Laura Phipps — of Alzheimer’s Research UK — also said that the study provided further evidence that a person can reduce their risk of dementia through lifestyle changes.
“This large-scale study adds to a robust body of evidence drawing a connection between physical health and brain health,” she told us. “Dementia risk is influenced by a complex mix of age, genetics, and lifestyle factors, and this research adds to previous studies suggesting that healthy behaviors may also be able to lessen the impact of certain risk genes.”
“The specific behaviors examined in this study — eating a healthy diet, staying physically active, not smoking, and not drinking to excess — are all known to be important for brain health, but the exact mechanisms underpinning this link are not yet fully understood. These results suggest that these heart-healthy behaviors may help to lower dementia risk by protecting against frailty as we age.”
– Dr. Laura Phipps
“It’s never too early or too late to take steps to think about brain health, and this study provides another reason to add healthy habits to your New Year’s resolutions. Visit www.thinkbrainhealth.org.uk for Alzheimer’s Research UK’s tips on how to keep your brain healthy and reduce the risk of dementia,” advised Dr. Phipps.