About 30 million people worldwide are living with Alzheimer’s disease, and there are nearly 10 million new cases every year. The disease is the main cause of disability and dependency among older people.
In 1901, the German psychiatrist Alois Alzheimer, identified the first case of what came to be known as Alzheimer’s Disease. His patient Augustine Deter was 50 years old. She had memory loss, delusions and a number of disturbing behaviours. When asked to write her name in one examination, she found she had forgotten. “I’ve lost myself,” Augustine said.
After one century, about 30 million people around the world are living with Alzheimer’s disease, and there are nearly 10 million new cases every year. The disease is the main cause of disability and dependency among older people. Alzheimer’s has not only physical, psychological, social, and economic impact on people who has it, but also on their carers, families and society at large.
According to the National Health Service (NHS), the definition of Alzheimer’s disease is: “It’s a progressive condition, which means the symptoms develop gradually over many years and eventually become more severe. It affects multiple brain functions.” People might want to ask: “What happens inside the brain to develop this disease?” Let’s start from the synapse, the connection point of two neurons.
The synapses are where neurotransmitters are produced, signals are transmitted and communication happens. It’s the place to form our thinking, senses and memory. It is also where Alzheimer’s happens. Apart from neurotransmitters, the synapses also release a chemical called amyloid beta. It’s normally cleared away by microglia, the janitor cells of our brains. While the causes of Alzheimer’s are still unclear, many scientists believe that the disease is due to the accumulation of amyloid beta in the synapse. When too much amyloid beta is released and not enough is cleared away, it begins to pile up, forming sticky aggregates called amyloid plaques. It is the time when people start to develop minor memory problems and it might not be detectable.
As amyloid beta accumulates, people start to develop short-term memory loss, they might not remember their names or what they had for breakfast. Later on, they may lose some of their motor skills, as well as language abilities. They may forget how to write or stumble while talking in their native language. However, it takes at least 15 to 20 years for amyloid beta to accumulate to its tipping point. When it comes, the microglia janitor cells get hyper-activated, releasing chemicals that cause inflammation and cellular damage. A vital neural protein “tau” starts to twist itself into “tangles”, which choke off the neurons from the inside. It’s the time when the Alzheimer’s symptoms get more obvious, people start to lose their long-term memory. They might not be able to recognize their spouses and could eventually lose their own identity. By the mid-stage of Alzheimer’s, massive inflammation and tangles in synapses are present, which lead to the death of brain cells. At this stage, people get disoriented and are at risk of getting lost. Eventually, people with Alzheimer’s disease die from multiple infections.
After understanding the development of Alzheimer’s disease, people may want to know the cause of this disease. Where does this disease come from, what makes it so deadly? There are many reasons behind the development of Alzheimer’s disease, one of them is DNA. Some people inherit a rare genetic mutation named APOE 4, which increases the amount of amyloid plaque. Lifestyle also matters. Researches have shown that a lifestyle of drinking, smoking, an unhealthy diet, poor sleep and stress are more likely to increase the level of amyloid plaque and tangled tau in the brain. Aging also contributes to Alzheimer’s. As people get older, there are fewer neuron cells functioning, the connections between neurons become less frequent, this could potentially accelerate the development of the disease.
It seems to be a bleak picture where so many factors can lead to Alzheimer’s, but is there any way to cure it? Unfortunately, the answer is no. According to the Alzheimer’s Association, there is currently no cure for the disease or a way to stop its progression. However, there are drug options that help to treat symptoms, as well as some non-drug approaches to prevent the disease from happening. Medications like AChE inhibitors and mematine are confirmed to be useful in protecting the connections between different neuron cells, to maintain a balanced level of different substances. Cognitive stimulation is also used to treat Alzheimer’s disease. Activities like reading a book, learning languages and solving science problems can help stimulate new connections between different neuron cells, this could potentially compromise synapses being lost due to the disease. What else?
In 1986, a researcher named David Snowdon chose nearly 700 nuns for his study on brain deterioration. All the nuns were aged over 75 and had a wide range of health conditions. They also agreed to a brain donation after death for future research. Throughout the 20 years of study, the nuns were given cognitive assessments and physical assessments. As a result, Snowdon concluded that the nuns who demonstrated a high level of linguistic ability, had higher cognitive test scores later in their lives. He also pointed out that the nuns who engaged regularly in mentally stimulating activities, have more neural connections to cope with potential Alzheimer’s in their lives.
This research leaves us with a few thoughts. Although our brain may start to show signs of deterioration very early in life, even 50-60 years before symptoms develop, there are ways to slow down the process. Reading books, learning a new language, keeping a balanced diet, talking to people and exercising more. Alzheimer’s might not be preventable, but by engaging in mentally and physically stimulating activities, we have more backup neuron connections to fight against it. The more new neuron connections we build, the less likely that Alzheimer’s will come to find us.
Words: Rui Cai | Illsturations: Rui Cai & Mingxin Yang