| Researched and written by ZOFIA HOCHTAUBEL
We can all agree that at some point we have heard something about Alzheimer's disease. It is the most common form of irreversible senile dementia. In 2020, around 50 million people worldwide suffered from it, and this number is projected to reach 152 million by 2050. This disease affects about 7% of the population over 60 years old and 40% of those over 80 years old. As we age, what changes in our brain cause Alzheimer’s disease?
The truth is that the molecular cause of this disease is not entirely known and is the subject of constant discussion. However, the majority of scientists agree that Alzheimer's disease is caused by a flaw in the protein's breakdown.
The product of this breakdown is β-amyloid, which is deposited in the extracellular space and in the walls of the blood vessels of the brain, forming amyloid senile plaques. It is assumed that amyloid protein is toxic and leads to damage to nerve cells.
The first to be damaged are the temporal lobes, more specifically the hippocampus, which is responsible for creating new memories. That is why the first symptom to be indicated is signs of forgetfulness. Additionally, people with this form of dementia use simpler language to deliver their message, for example, instead of being precise and using the word "document" they would say "paper" or "this thing".
Unfortunately, the disease doesn't stop at the temporal lobes. Over time, it spreads to the parietal lobe, where spatial information is processed. This results in a disturbance in awareness of the external environment. The people who are affected by this illness tend to forget places that are very familiar to them, ultimately getting lost.
Degeneration of neurons also occurs in the frontal and prefrontal cortexes. Symptoms of damage to this area include impaired logical thinking, decision-making, planning, and problem-solving. Alzheimer's disease also affects the neural pathways that store motion memories, making it difficult to remember how to do everyday tasks like eating and dressing.
Our limbic and amygdala systems, which are responsible for controlling our emotions and mood, are gradually taken over by the illness. Our minds become disorganized and as a result, we experience uncontrolled feelings of rage, remorse, and desire. A person who was always calm developed a pattern of frequent rage attacks. It's heartbreaking to witness our loved ones transform into someone entirely different.
Apart from the molecular causes of this disease, another controversy surrounds the risk factors. Researchers' opinions are biased, but many believe that increasing age, genetic factors, head injuries, vascular diseases, diabetes, infections, and environmental factors (such as heavy metals) increase the possibility of Alzheimer's.
But is there anything we can do to improve brain health or reduce Alzheimer's disease?
Yes, in fact, several studies have shown that physical activity activates brain vascularization and neurogenesis, which improve cognitive function in older people. Additionally, the Mediterranean diet and intellectual activity proved successful in reducing memory loss and increasing the brain's capacity.
The progression of the disease from the first symptoms to the advanced stage usually takes eight to ten years. Nevertheless, early diagnosis is crucial since it can provide prompt treatment. The bad news though, is that there is no cure for Alzheimer's disease as of yet, however, there are several treatments that can help with it!
Research on finding a cure is still ongoing and slowly moving forward. Hopefully, in the near future, we will find the answer to the question on how to win against Alzheimer's.
Sources:
“Recent Advancements in Pathogenesis, Diagnostics and Treatment of Alzheimer’s Disease” by Sahil Khan, Kalyani H. Barve, and Maushmi S. Kumar.
“Comprehensive Review on Alzheimer’s Disease: Causes and Treatment” by Zeinab Breijyeh and Rafik Karaman.
“Basic Clinical Neuroscience” by Ph.D. Paul A Young, Paul H. Young, Ph.D. Daniel L. Tolbert.
“Your Superstar Brain” by Kaja Nordengen.
“Remember: The Science of Memory and the Art of Forgetting” by Lisa Genova.
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