IN ONE of the many fascinating episodes in his book In Pursuit of Memory: The Fight Against Alzheimer’s, neuroscientist Dr Joseph Jebelli travels to Iceland to visit neurologist Dr Kari Stefánsson, who is carrying out groundbreaking research in the field.
Stefánsson, who has taken on the task of mining the genome of the entire
Icelandic population, teases Jebelli: “We haven’t the faintest idea how the brain generates memory… you’re going to write a book about a disease that assaults this function, but you cannot even define it. What the hell are you doing?”
When I ask Jebelli why the way memory works is still such a mystery, he answers with the polite weariness of someone who has ruminated on this question many times, and acknowledges the Sisyphean nature of his task.
“Understanding how memory works is the holy grail of neuroscience essentially. It is just very difficult to pin down where memory is — the brain is a mass of 100bn cells all firing electrical impulses to each other. To try and pin down how memory works within that, where it resides, is a very difficult task. That was a frustrating aspect of writing this book for me because
essentially Alzheimer’s is a disease that robs someone
of their memory. We are learning a lot about how memory works just by studying Alzheimer’s.”
While Jebelli was interested in neuroscience from a young age, it was his family’s experience that triggered his interest in exploring Alzheimer’s. His grandfather Abbas was a charming and sociable man who lived in Iran but visited Jebelli’s family in Britain regularly.
“I have very fond memories of him. He was always very engaging, chatty, full of life. Then, when I was around 12 years old, he started to become a different person. He would leave the dinner table, wander off and get lost. My dad would have to go out and find him. He seemed very confused and agitated.
"To begin with, he didn’t recognise me and my sister. Then the visits from Iran became less frequent until he was given a diagnosis. Seeing my granddad decline in that way, going from this larger-than-life character to a shell of his former self was a catalyst for me choosing to specialise in Alzheimer’s.”
Many neuroscientists believe Alzheimer’s is simply a form of accelerated ageing but Jebelli says the boundaries are very blurred.
“We still don’t understand where the cut-off point is and how we can define it. Even if it is an accelerated form of ageing, it should still be considered a disease. Age is the strongest risk factor for cancer, for instance, but we wouldn’t dream of saying cancer isn’t a disease.
“A lot of the processes that are common to normal ageing build up in the brain and we essentially think there is some sort of threshold moment that triggers those processes to then lead to a catastrophic death of brain cells. At the same time, there are lots of people who have the hallmarks of Alzheimer’s in their brain that remain cognitively
intact throughout their lives. Something has protected them, stopped the horse bolting, and we still don’t know what that is.
“Genetics probably plays a heavy role. Mapping out what projects the brain at a genetic level will be just as important as figuring out what the risk factors are.”
The most recent HSE
figures show 55,000 people in Ireland are living with
dementia and each year, more than 4,000 develop it. Internationally, it is believed almost 50m people
are living with the
disease. More and more cases of Alzheimer’s are being diagnosed — which can be put down to the fact that we are living longer. However, Jebelli says there is cause for optimism in terms of projections for incidence of the disease.
“The incidenc is not
increasing at the rate we once thought it was. Ten years ago, projections were worse than they are now. Most scientists put that down to having a healthier lifestyle.”
We are well used to
reading about how eating oily fish can prevent Alzheimer’s or the citing of environmental risk factors such as exposure to aluminium. How much faith can we place in lifestyle and nutrition as a way to prevent the disease? Jebelli says we cannot make overarching
assumptions based on single cases, especially when one considers how his grandfather did everything right in this respect.
“My granddad was very similar to the people I interviewed for the book in that he had a remarkably healthy life. He used to go trekking every day, he had a very good diet, he didn’t smoke, he barely drank. He was a very intelligent man and was very mentally engaged. There was nothing in his lifestyle that you could point to as
precipitating the mental decline. Even though there is evidence linking lifestyle to alzheimer’s, it works in the millions as opposed to the individual.”
The number of research projects into Alzheimer’s around the world is so
extensive now that Jebelli believes the eradication of the disease is not that far off in relative terms.
“There is a lot of research going on into Alzheimer’s now, compared to only a few decades ago, when it was considered career suicide if you went into that field. In terms of research, the wider the net we can cast, the better. Science doesn’t just work in a linear fashion, you are more likely to have a breakthrough if you have lots of different projects going on.
“We are still waiting for that eureka moment in Alzheimer’s — and it is much more likely to come with more and more research. The goal at the moment is to push the disease back because we now know there are signs of the disease that start to accrue in the brain, years or even decades before you see symptoms.”
It is often difficult to get an early diagnosis of
Alzheimer’s as many of symptoms are common to the normal ageing process. When should people or their families start to be concerned?
“One of the main symptoms is getting lost. A recent study at the University of Edinburgh published some very interesting results about how loss of navigation is one of the earlier signs — it may even occur before memory problems arise. It is really difficult because we all forget things as we get older and that is perfectly normal.
“A good way to think about it is when you get to a level of forgetfulness that starts to interfere with your day-to-day life, when it transforms into an almost malignant confusion. For example, if you are looking for your keys and glasses, then you find them but you start to think ‘what are these for?’. That is when it is something more sinister and when you should start thinking about going to see your GP.”
Jebelli is optimistic about what lies ahead. He says the web of treatment is widening while the traditionally difficult process of diagnosis is also improving.
“All of these early telltale signs that scientists can spot in the blood, spinal fluid and even the eye, that is getting a lot more advanced now. In terms of biomarkers the future will be a good, quick, effective blood test that will be able to tell you with a high degree of accuracy whether you will go on to develop Alzheimer’s — or at the very least, whether you are at high risk of developing Alzheimer’s. You can then take some drugs at a certain point in your life that then changes the disease course.”