A new study has found that changes in the brain linked to Alzheimer’s disease are more common than we thought in very old people, especially those aged 85 and older.
The research also found that these changes are not as common in people under 75, and they seem to happen less often in those with more education.
These changes, called Alzheimer’s disease neuropathological changes (or ADNC), happen when proteins build up in the brain. These proteins can damage and kill brain cells, especially in a part of the brain called the hippocampus, which is important for memory. When this happens, it can lead to memory loss and other symptoms of dementia.
The study was done by researchers from King’s College London, Stavanger University Hospital, and the University of Gothenburg. They used a new type of blood test, which is simple and non-invasive, to look for these changes.
This is a big deal because, until now, doctors had to do more difficult procedures like lumbar punctures or expensive PET scans to look for signs of Alzheimer’s. Because those tests are harder to do, scientists didn’t know how common ADNC really was in the general population.
In this study, researchers worked with over 11,000 people in Norway who were part of a large health study called the HUNT Study. Everyone in the study was aged 57 or older. The researchers tested their blood and looked for signs of ADNC.
They found that the older people were, the more likely they were to have these brain changes. For example, fewer than 8 out of 100 people aged 65 to 69 showed signs of ADNC, but more than 6 out of 10 people over the age of 90 had abnormal results. This means that Alzheimer’s brain changes are much more common in the oldest people.
The researchers also found that about 11% of people over age 70 might be able to get special treatments called monoclonal antibody treatments. These new treatments can slow down memory loss and other signs of Alzheimer’s disease, but they only work if people have these brain changes. So being able to find these changes with a simple blood test is very helpful.
They also looked at how common ADNC was in people who already had memory problems. About 60% of those with dementia had ADNC, and about 33% of people with mild memory problems had it. This shows that while ADNC is important, it is not the only reason people get dementia. Other health problems may also play a role.
One surprise from the study was that men and women were about equally likely to have ADNC at every age. This goes against past beliefs that Alzheimer’s disease is more common in women.
Professor Dag Aarsland, the lead researcher, said that this blood test could help doctors find signs of Alzheimer’s much earlier and much more easily. It could also help doctors decide who should get the new treatments that are becoming available. However, this test is not yet available through the UK’s National Health Service.
The researchers now want to see how well these blood tests can predict who will go on to develop dementia. They are also working with general practitioners to find out how these tests can be used in everyday medical care.
This study shows that as the world’s population gets older, finding ways to detect and treat dementia early is more important than ever. A simple blood test could make a big difference in helping people live longer and healthier lives with better brain health.
The study is published in Nature.
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