First described in 1906 by Dr. Alois Alzheimer, Alzheimer’s disease is the most common form of dementia, accounting for around 60-80% of cases. It is characterized by problems with memory, thinking and behavior.

Onset is most common in individuals aged 65 and over, although people in their 40s and 50s can develop what is classed as early-onset Alzheimer’s.

Alzheimer’s is a progressive disease, meaning memory loss is mild in the beginning, but it worsens over time to the extent that individuals are unable to have conversations or respond to their surroundings.

There are treatments that have been approved by the US Food and Drug Administration (FDA) for Alzheimer’s. For example, cholinesterase inhibitors and memantine can help treat memory and thinking problems. But these drugs just help manage the symptoms; there is currently no cure for the disease.

In the US, around 5 million people aged 65 and over are living with Alzheimer’s, the majority of whom are women. This number is expected to almost triple to 16 million by 2050. Figures are similar worldwide; by 2050, more than 115 million people are expected to have the disease.

Current Alzheimer’s prevalence in the US makes it the 6th leading cause of death, killing more than half a million seniors every year. To put this in perspective, Alzheimer’s disease currently kills more people each year than prostate cancer and breast cancer combined.

Heather Snyder, PhD, director of medical and scientific operations at the Alzheimer’s Association, stated an interesting fact when talking to Medical News Today:

This is certainly not through lack of trying. In the last month alone, we have reported how scientists restored memory and learning deficits in Alzheimer’s mouse models, how vitamin D deficiency could increase the risk of developing dementia, and how DNA methylation in the brain is linked to Alzheimer’s.

But what have these studies taught researchers about Alzheimer’s so far?

Preventing and targeting plaques and tangles

As with all diseases, knowing exactly what causes Alzheimer’s is key to identifying ways to prevent and treat the condition.

Past research has indicated that Alzheimer’s occurs when two abnormal brain structures - plaques and tangles - damage and kill nerve cells, causing the memory, thinking and behavioral problems associated with the disease.

Plaques are fragments of a protein called beta-amyloid, which build up in areas between nerve cells. Tangles are twisted fibers of a protein called tau, which accumulate inside brain cells.

Although the jury is still out on the exact roles plaques and tangles play in the development of Alzheimer’s, studies have suggested that build up of these proteins begins long before symptoms develop.

“Evidence suggests that the process of Alzheimer’s disease begins more than a decade before clinical symptoms appear, suggesting we may need to intervene earlier to have a major impact on the course of the disease, particularly when using therapies designed to prevent the development of abnormal protein structures - plaques and tangles - that are abundant in the brains of people with Alzheimer’s,” says Snyder.