Can Alzheimer’s be cured?

Scientists have discovered an additional 42 genes connected to the development of Alzheimer's disease, according to a landmark study that is the result of 30 years of work.

Professor Julie Williams, Centre Director at the UK Dementia Research Institute (DRI) in Cardiff, said in a statement that “genetics has and will continue to help us identify specific disease mechanisms which we can target therapeutically. This piece of work is a major leap forward in our mission to understand Alzheimer’s, and ultimately produce several treatments needed to delay or prevent the disease.”

The highly collaborative, international project was carried out in research centres in eight partner countries including the UK, US, Australia and across Europe.

The study provides compelling evidence to support the role of inflammation and the immune system in the disease. It also confirmed previous findings implicating the proteins amyloid-beta and tau, that build up in and around nerve cells as Alzheimer’s disease progresses. 

Powerful dataset

The study involved researchers analysing the genomes of more than 100,326 people with Alzheimer’s disease and comparing them with over 600,000 healthy individuals to look for differences in their genetic makeup.

By pooling together these results, they were able to create an extremely large and powerful dataset.

“This study more than doubles the number of identified genes influencing risk for the more common form of Alzheimer’s disease,” said Dr Rebecca Sims, a Senior Research Fellow at Cardiff University and co-leader of the study.

‘It provides exciting new targets for therapeutic intervention and advances our ability to develop algorithms to predict who will develop Alzheimer’s in later life.” 

Why is Alzheimer’s complex?

Alzheimer’s is a disease that slowly and progressively destroys the brain. It is describedas a complex disease because it can be influenced by a range of genetic and environmental factors. 

There is a significant rise in the number of people with Alzheimer’s disease over the age of 65 years. However, most people over 80 years remain mentally alert.

As the condition advances, brain cells die and connections among these cells are broken, causing cognitive symptoms to increase.

Although the risk of developing Alzheimer’s increases with age, old age is not considered a cause of the disease.

The risk of developing Alzheimer’s can be attributed to the environment and lifestyle. For example, obesity has been linked to an increased risk of Alzheimer’s disease, while people who regularly engage in intellectual activities show a reduced risk of developing the disease. 

READ MORE: Blood test might show early signs of Alzheimer’s disease

Treatments

There is no cure for Alzheimer's, but there are medications that can impede the disease’s progression.

In recent years, scientists have made tremendous progress in better understanding Alzheimer’s and developing and testing new treatments, including several medications that are now in late-stage clinical trials.

According to the Alzheimer’s Association, the US Food and Drug Administration (FDA) has approved medications that fall into two categories: drugs that may change disease progression in people living with Alzheimer’s, and drugs that may temporarily mitigate some symptoms of the disease. Treatments may be available in different forms like a pill or patch.

Expanding studies

In ongoing clinical trials, scientists are developing and testing several possible interventions, including immunisation therapy, drug therapies, cognitive training, physical activity, and treatments for cardiovascular disease and diabetes.

The next step towards finding treatments for Alzheimer’s is for researchers to focus on the specific risk genes identified in this study and closely examine their role in the dysfunction and death of brain cells.

Much of this work is already underway in places like the UK DRI. Progress made in other conditions like cancer may accelerate the process, as drugs targeting these biological pathways are already in development.

Bart De Strooper, Director of the UK DRI, said, “ambitious studies like this are the fuel for the breakthroughs we need in dementia research. They show us that there is still much to learn about neurodegeneration, and continued investment in fundamental, discovery science is key to unlocking the secrets of Alzheimer’s and other dementias.”

Based on these results, the researchers also devised a genetic risk score to determine how likely patients with cognitive impairment are to go on to develop Alzheimer’s disease within three years of first showing symptoms.

Scientists hope the findings can be used to identify people within the population who are at greatest risk of developing Alzheimer’s disease before they start to develop the condition.

The authors of the study also stated that in the future it will be important to broaden studies to look at other demographics, as the present study was primarily conducted on Caucasian populations. 

READ MORE: US approves first new Alzheimer's drug in two decades