Until now, the spotlight has very much been on the amyloid theory of Alzheimer’s, which suggests that Alzheimer's disease is caused by the accumulation of beta-amyloid protein in the brain. Beta-amyloid is a protein fragment that is produced naturally in the brain, but in individuals with Alzheimer's, it clumps together to form sticky plaques that accumulate in the spaces between the brain's nerve cells.
The plaques are believed to interfere with communication between nerve cells, leading to the cognitive decline associated with Alzheimer's disease. Deposits of the protein tau can also contribute by forming tangles within brain cells. In affected brain cells, there is a reduction in neurotransmitters; individuals with Alzheimer's disease exhibit notably low levels of acetylcholine.
However, some of the focus on Alzheimer's has now shifted to mitochondria. Previously, scientists had noticed mitochondrial differences between people with and without Alzheimer’s disease, including a decreased number of mitochondria as well as malformed mitochondria. New evidence hints that a lack of healthy mitochondria numbers could be resulting in energy problems in the brain and also a buildup of toxic byproducts, which further deteriorates the health of the cells and contributes to their premature death.
Additionally, this mitochondrial theory offers an explanation as to why numerous genetic and environmental factors can enhance susceptibility to brain deterioration, since a range of these factors contributes to low energy levels.
Although the exact cause of Alzheimer’s disease has yet to be conclusively proven, several factors are known to increase the risk of developing the condition, including family history, Down's syndrome, head injuries, and cardiovascular disease. Research has shown that certain lifestyle factors associated with cardiovascular disease can also increase the risk of Alzheimer's.
The best things we can do are to keep our bodies as healthy as possible and ensure that the correct interventions are in place for those living with Alzheimer’s, as we wait in eager anticipation to see what further research will reveal.