A new study, published in Neurology, recruited neurologically healthy older adults without measurable cognitive impairments, but who had concerns about their memory. The scientists looked for links between memory loss and signs of Alzheimer’s disease (AD). They found that people who self-reported memory loss were more likely to have elevated levels of proteins associated with Alzheimer’s. If further research backs up these findings, it could help doctors catch the condition at an earlier stage, allowing treatment to start earlier. Around 675 older adults were recruited all above the age of 72. These participants took cognitive tests which showed that they had no impairments as such. Each recruit had a partner, which could be a child, spouse, or friend — 65% of these partners lived with the participant. Participants answered questions about their memory and thinking skills and how well they performed daily tasks. Their partners also answered the same questions about the participants.
Each of the participants underwent a brain scan to look for protein markers of Alzheimer’s disease known as amyloid plaques and tau tangles. Even though the precise mechanisms that lead to Alzheimer’s disease are not confirmed, amyloid plaques which are the protein buildup between neurons and tau tangles which are protein buildup within neurons come close to being associated with the disease.
Both of these limit cells’ ability to signal to each other. Eventually, this leads to cell death. Over time, as more cells die, it reduces cognitive ability, and the brain can shrink or atrophy. These proteins “interfere with the formation of memories at both the biochemical level and structural level through interference with the physical integrity of neural networks. The patterns of impaired memory functions observed relate to changes in the structure and function of the brain.
The brain scans showed that individuals with self-reported memory problems had higher levels of tau tangles. This association was even stronger in people who also had higher levels of amyloid. In other words, people who experience memory problems are more likely to have neurological signs of Alzheimer’s despite being cognitively healthy. The findings in this study suggest that asking older people who have elevated Alzheimer’s disease biomarkers about subjective cognitive decline may be valuable for early detection. This is particularly important since it is predicted that treatments given at the earliest diagnosable form of the disease will be the most effective in slowing down the disease.
While a steady cognitive decline is often part of normal ageing, Alzheimer’s and other dementias are not. Even though factors like genetics and age cannot be changed, some risk factors are modifiable. For instance, lack of physical activity, smoking, and continuous consumption of alcohol and junk food among many other factors are in one’s control. Doctors agree that it is beneficial to start as early as possible and maintain a healthy lifestyle, but it is never too late.
