Every six minutes, a new and incurable case of Alzheimer’s is diagnosed in Australia.

The four approved medications on the market dampen the symptoms in some patients, but cannot stop, slow or reverse the disease itself as it eats away a once-healthy brain. Yet there is hope as new research from the US could pave the way for future treatments.

“Removing [the gene] from the brain might be good for Alzheimer’s disease, but might be absolutely terrible for all other aspects of health.”

For more than two decades, researchers have known that a gene, APO-E, is the main genetic risk factor for the disease.

• Why dementia is scarier than cancer for over 50s
• Five steps to reduce your risk of Alzheimer’s
• Dr Google and the perils of self-diagnosis online

New research could pave the way for Alzheimer’s treatment.

Until now, a big question mark has hung over whether APO-E 4, the worst of three variants of the gene, could be safely ‘switched off’ without damaging the human brain.

Estimates vary, but those with one copy of the gene (about 25 per cent of the population) may have as much as a five times greater risk of developing the disease, while those with two copies (about 2 per cent of people) could have up to 15 times the risk.

Previous studies in mice bred without the gene produced muddled results – some found neurological side effects, others didn’t.

A case study published this week in JAMA Neurology could encourage further study of APO-E 4.

Researchers at the University of California examined a 40-year-old African American man born without the gene, and found that he exhibited normal brain function.

At first glance, this seems to settle the question of whether researchers could safely tinker with the human genome to rid our bodies of APO-E 4 altogether, or mutate it to the APO-E 2 variant, which may actually protect against Alzheimer’s in some people.

A diagnosis with dementia is always terminal.

An editorial written by two of the study’s authors says that proving a lack of cognitive side effects is “essential” to the development of Alzheimer’s drugs based on the gene.

But Alzheimer’s Australia national research manager Dr Chris Hatherly sees several major drawbacks to the study.

The big caveat is that the man also suffers from a rare genetic disorder (called dysbetalipoproteinemia), which caused his cholesterol levels to spike so much that bulbs of fat popped up on his hands, elbows and ears. This may or may not be related to his lack of the APO-E 4 gene, which plays a very important role in the body’s metabolism of cholesterol.

“Simply by removing [the gene] from the brain might be good for Alzheimer’s disease, but might be absolutely terrible for all other aspects of health,” Dr Hatherly warns.

It is also a single case study. If further research confirms the results, it will still be many years before a treatment hits our shelves because tampering with human genes is pretty much impossible at the moment.

Dr Hatherly says it is “not at all straightforward” to add, remove or mutate genes. “Modifying those genes outside of the embryonic stage is next to impossible. Genetic medicine is still a long way off,” he says.

Desperate need for a breakthrough

More than 332,000 Australians now live with Alzheimer’s

If no medical breakthrough is made, the impact of Alzheimer’s disease will dramatically increase.

According to modelling by Alzheimer’s Australia and various government agencies, more than 332,000 Australians now live with the disease. By 2050, this number is expected to increase to almost 900,000, and 135 million worldwide.

By the 2060s, spending on dementia is projected to be $83 billion (in 2006-07 dollars), which will outstrip spending on any other health condition and represent about 11 per cent of total spending in the health and residential aged care sector.

Promising research

Several final-stage human trials of Alzheimer’s drugs have failed in recent years, at a loss of many billions of dollars.

Despite these setbacks, there is some “very promising” research currently underway in early detection using brain imaging and blood tests.

“It’s possible to detect the very earliest stages of Alzheimer’s disease up to 17 or even 20 years before the symptoms appear,” Dr Hatherly says.

“As the research community starts being able to screen larger numbers of people with these tests and get them into studies at very, very early stages of the disease,

The early stages of Alzheimer’s can be detected years in advance.

well before any symptoms, there’s quite a lot of optimism that the treatments we have at the moment and some that are in the pipeline will be much more effective,” he says.

Life doesn’t end with a diagnosis

While a diagnosis with dementia is always terminal, it does not mean that life is over.

“Many people with dementia live for many years with very high levels of independence and wellbeing,” Dr Hatherly says. “If people can get a diagnosis in a timely manner, it can absolutely help.”

The benefits of an early diagnosis are early drug treatments for symptoms, better planning for the future, and maximum enjoyment of the earlier years of the disease.

Statistics provided by Alzheimer’s Australia. Those seeking more information about the disease are encouraged to call the National Dementia Hotline on 1800 100 500.

Take a closer look into Alzheimer’s Disease with International Approaches to Alzheimers Disease and Dementia by Lorraine N. Salomon. Buy it here.

This book provides a comparison of international approached to dealing with Alzheimer's disease and dementia, as well as discusses the effect this disease has on the brain and its function.