Many people fear dementia, especially if they have seen a loved one struggle with memory loss and confusion.
When a parent or sibling develops Alzheimer’s disease or another type of dementia, it is common to wonder, “Will this happen to me too?”
New research from the University of California, San Francisco offers both a warning and a message of hope.
The study shows that while genes do play an important role in determining who may develop dementia, many other risk factors are linked to heart and lifestyle health, and these can be changed.
Dementia is a general term for a group of conditions that affect memory, thinking, learning, and the ability to carry out daily activities.
Alzheimer’s disease is the most common form. As people live longer, more individuals are at risk, and the number of people affected by dementia continues to grow worldwide.
Scientists estimate that genes explain about half of the risk for developing dementia. This may sound frightening, because we cannot change the genes we are born with. However, the other half of the risk is related to factors that are strongly linked to lifestyle and general health.
The research team, led by Shea Andrews at UC San Francisco, looked at information from around 3,500 older adults who took part in two major research programs: the National Alzheimer’s Coordinating Center and the Alzheimer’s Disease Neuroimaging Initiative.
The average age of participants was 75 years old, and none of them had dementia at the beginning of the study. About one in four participants had mild cognitive impairment, which is an early stage of memory and thinking problems that may later develop into dementia.
Over the next six years, around one in seven participants died, and among those who survived, about one in four progressed to full dementia.
The researchers examined several different types of risk. First, they looked at whether a participant had a close family member, such as a parent or sibling, who had dementia. They also checked for the presence of a gene variant called APOE4, which is known to strongly increase the risk of Alzheimer’s disease.
In addition, they calculated something called a polygenic risk score. This score combines the effects of many small genetic changes that together can increase the chance of developing dementia. Finally, they measured each person’s cardiovascular risk. This included factors such as high cholesterol, especially LDL cholesterol, high blood pressure, obesity, and diabetes.
What they discovered was very clear. The more risk factors a person had, the more likely they were to develop dementia. Having only one of these factors increased the risk by about 27 percent. Having two factors raised the risk by about 83 percent.
With three factors, the risk doubled. When all four factors were present, the risk increased five times. This shows that dementia does not usually come from one cause alone. Instead, it is the combined effect of genes and heart health that shapes the future risk.
The encouraging part of this study is that although we cannot change our family history or our genes, we can change many of the other risk factors. High blood pressure, high cholesterol, obesity, and lack of physical activity all increase the strain on the brain and the blood vessels that feed it.
Over many years, this damage builds up and affects memory and thinking. By improving diet, exercising more, stopping smoking, managing stress, and treating conditions like hypertension and diabetes, it may be possible to lower overall brain damage and delay or even prevent the symptoms of dementia.
The researchers also pointed out that in the past, there have been limited treatments for Alzheimer’s disease, which made early risk identification feel less useful. Now, new treatments are being developed that may slow the progression of the disease, especially in its earliest stages.
Dementia risk and early brain changes can now sometimes be detected with blood tests or advanced brain scans called PET scans. This means that in the near future, doctors could combine genetic information with heart and lifestyle data to create a more personal and effective prevention plan for each patient.
In reviewing and analysing this study, the most important message is that a person is not helpless in the face of dementia risk. Even if someone has a strong genetic background for Alzheimer’s disease, their lifestyle choices and heart health still matter greatly. By focusing on what can be controlled, people can take an active role in protecting their brain.
This research supports a future where dementia prevention is more personalised and more hopeful. Instead of waiting for symptoms to appear, individuals and their doctors can work together to reduce risks, protect brain health, and possibly change the course of the disease before it begins.
If you care about dementia, please read studies about dietary strategies to ward off dementia, and how omega-3 fatty acids fuel your mind.
For more health information, please see recent studies about Choline deficiency linked to Alzheimer’s disease, and what to eat (and avoid) for dementia prevention.
The study is published in Alzheimer’s & Dementia.
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