What causes cognitive decline and brain damage in Alzheimer’s disease? Is it mostly genetic or are other factors more important? The story is more complicated than it seems at first glance. Read on to find out about what scientists think might be the drivers and risk factors of this disease. Alzheimer’s Disease Causes
In this post, you will read not only about the hallmarks of Alzheimer’s disease but also about how research suggests that the modern lifestyle, your environment, and genetic factors might contribute to it. The Brain’s Silent Battle
One fact is clear: Alzheimer’s disease is a result of gradual brain cell loss. Researchers explain that brain degeneration specific to the disease happens through a complex cascade in which harmful factors overcome the brain’s defenses [ 1 ].
Studies emphasize that this diseases cascade isn’t activated overnight. Small and silent changes in Alzheimer’s disease occur 20 years before people experience the first symptoms [ 2 ].
According to one hypothesis, it’s probably at this stage – or before – that the battle between your brain’s defenses and stressors reaches its peak. Some scientists argue that it is at this point that people may have the greatest chance of changing the outcome. This is still an experimental stance, and more research is needed to verify it.
According to the National Center for Complementary and Alternative Medicine (NCCIH) [ 3 ]:
“Currently, there is no strong evidence that any complementary health approach or diet can prevent cognitive impairment.”
The exact underlying cause of Alzheimer’s is still unclear. However, there is probably no single cause of Alzheimer’s. Just as there is no single cause of high blood pressure, diabetes, or depression [ 4 ].
Scientists think that the disease is caused by a combination of factors over time. As with all diseases, various factors add up. Theoretically speaking, one damaging factor can be neutralized with a stronger protective factor – or it can be worsened with another stressor.
The latest research suggests that a combination of genetic factors, lifestyle and environmental influences, infections, gut flora imbalances, and aging all play a role. Together, they are thought to lead to brain inflammation, oxidative stress , beta-amyloid buildup, and neurotransmitter imbalances. The end result is brain cell loss and dementia. The Modern Lifestyle Hypothesis
Though Alzheimer’s is commonly diagnosed in people over 65 years old, many people nowadays start to experience signs of cognitive decline at a much younger age.
For this reason, Alzheimer’s is now being reframed by some scientists as a disease of the modern, sedentary, unhealthy lifestyle – much like obesity and type 2 diabetes. This stance is still experimental, however [ 5 ].
Nonetheless, based on this theory, scientists speculate that the type of lifestyle someone leads can have a large impact on brain health.
No clinical evidence backs up this hypothesis, though.
On the other hand, there’s evidence that type 2 diabetes and heart disease are strongly linked to the development of Alzheimer’s disease. These chronic diseases can be prevented by eating a healthy diet and exercising. By lowering your risk of one chronic disease, you might also lower your risk of many others – killing two birds with one stone [ 6 , 7 , 8 , 9 ].
If you are experiencing cognitive issues – including those of poor memory, forgetfulness, or personality changes – it’s important to talk to your doctor, especially your symptoms are significantly impacting your daily life.
Major memory and behavior changes – such as forgetting recent events or conversations, misplacing your possessions, getting lost in familiar places, having trouble finding the right words to describe something, and low mood or apathy – are all reasons to see a doctor.
Many conditions, some of which are treatable, can result in poor memory or other symptoms of cognitive impairment or dementia.
Your doctor should diagnose and treat the condition causing your symptoms.
Likewise, if you are concerned about the symptoms of someone close to you, talk to them about scheduling a doctor’s appointment and going there together.
Many people with cognitive decline are not fully aware of their own memory and behavior, and the support of loved ones can be indispensable. Research on Potential Alzheimer’s Disease Causes
Since the exact cause of Alzheimer’s disease is unknown, all the factors and processes outlined below are experimental and their contribution to disease development uncertain. The aim of this section is to outline research findings for informational purposes only. 1) Beta-amyloid Plaques May Block Brain Communication
The Hallmark of Alzheimer’s?
Beta-amyloid protein deposits have been regarded as the hallmark of Alzheimer’s disease for decades. They were first discovered as highly-concentrated plaques in Alzheimer’s patients [ 10 , 11 ].
However, beta-amyloid proteins are not only “bad” – scientists hypothesize that they only become toxic once they create large deposits. At normal levels, these proteins seem to perform beneficial functions, like fighting infections in the brain [ 10 , 11 ].
Research suggests that healthy brains can break down and clear beta-amyloid proteins before they cause damage [ 12 ].Researchers suggest that, in Alzheimer’s disease patients, the removal process doesn’t work as well as it should. This appears to ultimately lead to a buildup of beta-amyloid proteins, which clump together and form plaques [ 12 ].According to preliminary research, plaque deposits form between brain cells, fading and weakening communication clefts or synapses between the cells [ 13 ].When synapses are lost, neurons become disconnected and eventually die. Plaque deposits might also kill neurons by other means, such as by increasing inflammation and oxidative damage – but this is also uncertain [ 13 ]. Gaps in the Theory This theory doesn’t completely hold up. Scientists recently discovered that it suffers from the following major problems [ 14 ]: Many elderly people without dementia have amyloid deposits Some Alzheimer’s patients have few amyloid deposits but significant dementia Animal studies reveal that these plaques don’t always kill brain cells or cause dementia Drugs that reduce beta-amyloid deposits have generally failed to improve dementia in clinical trials […]