Researchers have reported that warning signs of Alzheimer's disease may appear in middle age, specifically at age 45, decades before the usual symptoms that typically do not appear until the seventies or later.
Researchers believe that combining a simple blood test with listening to a person's complaints about their memory could be a powerful tool for early disease detection, potentially offering an opportunity to prevent or slow the progression of the disease before it is too late.
Alzheimer's disease is known as a disorder that affects the brain and gradually destroys its cells, and it has a very long stage that precedes the obvious symptoms and may begin 20 or 30 years before the actual diagnosis.
In the past, Alzheimer's could only be diagnosed after death or through invasive and unpleasant tests such as lumbar punctures, but researchers are now working on developing simpler blood tests.
One of these promising indicators is a protein called pTau181, which is very high in people with Alzheimer's, but researchers were unsure when this protein begins to accumulate.
A team from the University of Otago in New Zealand used data from the famous Dunedin Study, which has been tracking and investigating the health, behavior, and development of humans from birth to old age for more than 50 years.
The participants were 45 years old at the time of the study. Researchers examined the participants' blood and found that elevated levels of the pTau181 protein were associated with complaints reported by the participants themselves, such as a decline in memory or thinking skills. This was occurring at the young age of 45, at least three decades before the age at which Alzheimer's disease is typically diagnosed.
This discovery is important because new drug treatments for Alzheimer's work best when given early. These treatments do not cure the disease completely, but they slow its progression; however, they cannot restore lost cognitive functions in advanced stages. Therefore, detecting early signs offers an opportunity for treatment before permanent brain damage occurs.
Prevention is also possible through simple lifestyle changes such as physical activity, social engagement, blood pressure control, and treatment of hearing problems. The earlier these measures are implemented, the more effective they are.
Forgetfulness with age is common and usually not a cause for concern, but for some, it can be the beginning of Alzheimer's. Subtle memory changes that a person notices often occur years before diagnosis and may be the first time they realize something is wrong. Testing for the pTau181 protein, when combined with these subjective complaints, can help differentiate between normal forgetfulness and early signs of Alzheimer's.
But questions remain open. Researchers found no link between the pTau181 protein and the results of brain MRI scans, nor with the performance of participants in memory and thinking tests at age 45.
There are two possible explanations: First, the protein rises very early in life when a person notices memory decline, but the changes don't yet show up in brain scans. Second, elevated levels of this protein in middle age may not be related to Alzheimer's at all and may simply be beneficial for older adults.
