Kelly McSweeney

Feb 5th 2021

Dementia and Our Brains


An estimated 50 million people worldwide are living with a form of dementia, a disease that deteriorates one of humanity’s most precious resources: memory. Just as our bodies change as we get older, some changes in the brain are a normal part of aging. It’s natural to lose some neurons as you get older, but if you have dementia, this loss of brainpower happens at much a faster rate and causes widespread damage throughout different areas of the brain.

While early stages include mild symptoms such as forgetfulness, as the disease progresses, it snuffs out the brain’s ability to think, speak and function. There is no cure yet. Researchers are working to find a deeper understanding of what’s happening on the cellular level so that we can delay and possibly even prevent the brain from shutting down.

Normal Aging Versus Brain Diseases

Contrary to previous misconceptions, scientists now understand that dementia is not a normal part of aging. People who have dementia experience a loss of cognitive functioning, including thinking, remembering and reasoning. As the disease progresses, it interferes with the person’s daily activities and, eventually, causes them to need constant assistance in order to live. The World Health Organization (WHO) says that dementia is a major cause of disability and dependency worldwide.

Our brains are filled with billions of neurons, the specialized cells that process information and transmit signals between different parts of the brain to the rest of our body. These cells are responsible for our thoughts, feelings and movements. If something goes wrong, these neurons stop working. New advancements in imaging techniques have allowed researchers to physically see what happens to the brains of people with dementia.

Alzheimer’s disease, the most common form of dementia, physically shrinks the brain. U.S. News reports that a third of the brain disappears from atrophy, neuron loss and white matter loss.

Dementia doesn’t just cause memory loss. In the advanced stages of the disease, it also affects language skills, visual perception, problem solving, self-management and the ability to focus, according to the National Institute on Aging (NIA).

The current scientific understanding is that Alzheimer’s disease is caused by two proteins that become toxic in the brain. These proteins, called amyloid plaques and tau tangles, collect in the brain and eventually cause atrophy.

While Alzheimer’s is the most common cause of dementia (associated with 60% to 80% of cases, according to the NIA), there are also other types and causes. Brain damage can also be caused by the vascular system failing to deliver enough blood and nutrients to the brain. Plus, some cognitive problems occur because of chronic inflammation or not having enough glucose to power its normal activity.

Stages of Brain Diseases

1. Early Stage: Forgetfulness

In the early stage, symptoms can be subtle or even undetectable. According to U.S. News, in the earliest (preclinical) phase, there are some changes in the brain, but symptoms can be so mild that the patient and doctor may not notice anything wrong.

The first part of the brain that Alzheimer’s damages is the hippocampus, which is the region associated with learning and memory formation. At this stage, old memories remain, but newer ones don’t stick. This causes problems such as forgetting where you put things and repeating questions.

Although we don’t have the ability to resuscitate dead neurons, sometimes, the underlying condition is treatable, so early diagnosis can benefit from available treatments.

2. Middle Stage: Communication Difficulties

In early stages, different types of dementia and their symptoms look alike, but as the disease progresses, more areas of the brain are affected. For example, damage spreads to the cortex, the thin outer layer of the brain associated with language, reasoning and social behavior. This causes more symptoms beyond forgetfulness, such as worsening language, visuo-spatial skills and executive function.

3. Late Stage: Need for Assisted Self-Care

In severe stages of the disease, even more neurons die and many areas of the brain are damaged. People with late stages of dementia are no longer able to live without constant care. Eventually, the disease is fatal.

The Future

There is no cure for dementia. However, there are ways to help prevent or reduce the onset of symptoms:

  • Pharmaceutical drugs such as those that reduce the toxic proteins

  • Therapies that target the vascular system, glucose metabolism and inflammation

  • Lifestyle interventions such as physical exercise and diet changes that can delay the onset of symptoms

  • Behavioral changes that improve brain health

Dementia is heartbreaking, and it’s so common that WHO points out that it has a physical, psychological, social and economic impact on society at large. Up until recently, dementia was considered part of the aging process. However, we’ve now seen that the type of brain damage that accompanies dementia is far beyond what is typical for those brains that have not been afflicted. With an aging population of baby boomers, there may be more research funding for clinical trials that can look at the mechanisms of this disease and potential treatments.