Stretching your mind with mentally challenging activities can help improve your memory. (Shutterstock)
Do we really lose thousands of brain cells every day in older age?
Answer: For years, experts believed that, unlike many other cells in the body, neurons did not regenerate. They thought that the brain produced new brain cells only early in life and that once you reached adulthood, the growth of new neurons ceased and existing neurons began to die off.
You may have heard the oft-repeated “fact” that you lose 10,000 brain cells a day. The idea was that your brain was shrinking, and that could mean only one thing: as you lost neurons, you also lost some of your capacity to learn, think, and remember. Researchers now know that this neuron degradation is less pronounced than previously thought.
Not only do brain cells not die as rapidly as scientists once believed, but it may even be possible to grow a modest number of new neurons — a process known as neurogenesis. About two decades ago, compelling evidence showed that human adults do sprout new neurons in the hippocampus. The hippocampus plays a key role in acquiring and consolidating new memories.
While certain brain regions may take a hit as we age, the brain is also quite adaptable. The complex network of interconnected neurons through which it processes information is fairly dynamic, changing constantly throughout life in response to everyday experiences — a phenomenon called neuroplasticity.
Neuroplasticity is probably more important for memory than neurogenesis. Developing and maintaining connections among neurons forms neural pathways among brain cells as you learn new information or have experiences.
Revisiting the information strengthens the pathways. In fact, any activities you engage in frequently — whether related to your job, your hobbies, or running a household — become more sturdily encoded.
The brain also has some capability to reorganize itself, shifting functions from one network to another, if a particular process starts to weaken. For example, some studies have found that the brains of older and younger adults may engage different brain regions to accomplish the same mental task. Scientists believe that this may be a mechanism of older brains to compensate for diminished function in the area normally used for that task.
New connections between neurons form as we learn information, hear sounds, touch things, or take in visual images in our environment. The more we use the information, the stronger the memory. Even if some brain regions weaken, the brain may be able to compensate. For these reasons, stretching your mind with mentally challenging activities can help improve your memory.
If you’re in your 80s or 70s and you’ve noticed that you’re having some memory loss, it might be reasonable to be concerned that you could be developing Alzheimer’s disease or another form of dementia. But what if you’re in your 60s, 50s, or 40s… surely those ages would be too young for Alzheimer’s disease or dementia, right?
About 10% of Alzheimer’s disease is young onset, starting before age 65
To be clear, young onset dementia (by definition starting prior to age 65, and sometimes called early onset dementia) is uncommon. One study in Norway found that young onset dementia occurred in 163 out of every 100,000 individuals; that’s in less than 0.5% of the population. So, if you’re younger than 65 and you’ve noticed some trouble with your memory, you have a 99.5% chance of there being a cause other than dementia. (Whew!)
There are a few exceptions to this statement. Because they have an extra copy of the chromosome that carries the gene for the amyloid found in Alzheimer’s plaques, more than half of people with Down syndrome develop Alzheimer’s disease, typically in their 40s and 50s. Other genetic abnormalities that run in families can also cause Alzheimer’s disease to start in people’s 50s, 40s, or even 30s — but you would know if you are at risk because one of your parents would have had young onset Alzheimer’s disease.
How does young onset Alzheimer’s disease differ from late onset disease?
The first thing that should be clearly stated is that, just as no two people are the same, no two individuals with Alzheimer’s disease show the same symptoms, even if the disease started at the same age. Nevertheless, there are some differences between young onset and late onset Alzheimer’s disease.
People with typical, late onset Alzheimer’s disease starting at age 65 or older show the combination of changes in thinking and memory due to Alzheimer’s disease plus those changes that are part of normal aging. The parts of the brain that change the most in normal aging are the frontal lobes. The frontal lobes are responsible for many different cognitive functions, including working memory — the ability to keep information in one’s head and manipulate it — and insight into the problems that one is having.
This means that, in relation to cognitive function, people with young onset Alzheimer’s disease may show relatively isolated problems with their episodic memory — the ability to form new memories to remember the recent episodes of their lives. People with late onset Alzheimer’s disease show problems with episodic memory, working memory, and insight. So, you would imagine that life is tougher for those with late onset Alzheimer’s disease, right?
Depression and anxiety are more common in young onset Alzheimer’s disease
People with late onset Alzheimer’s disease do show more impairment, on average, in their cognition and daily function than those with young onset Alzheimer’s disease, at least when the disease starts. However, because their insight is also impaired, those with late onset disease don’t notice these difficulties that much. Most of my patients with late onset Alzheimer’s disease will tell me either that their memory problems are quite mild, or that they don’t have any memory problems at all!
By contrast, because they have more insight, patients with young onset Alzheimer’s disease are often depressed about their situation and anxious about the future, a finding that was recently confirmed by a group of researchers in Canada. And as if having Alzheimer’s disease at a young age wasn’t enough to cause depression and anxiety, recent evidence suggests that in those with young onset Alzheimer’s disease, the pathology progresses more quickly.
Another tragic aspect of young onset Alzheimer’s disease is that, by affecting individuals in the prime of life, it tends to disrupt families more than late onset disease. Teenage and young adult children are no longer able to look to their parent for guidance. Individuals who may be caring for children in the home now need to care for their spouse as well — perhaps in addition to caring for an aging parent and working a full-time job.
What should you do if you’re younger than 65 and having memory problems?
As I’ve discussed, if you’re younger than 65 and you’re having memory problems, it’s very unlikely to be Alzheimer’s disease. But if it is, there are resources available from the National Institute on Aging that can help.
You’ve got a swag of scholarships and fellowships under your belt and you’re in demand as a guest speaker in Australia and overseas.
You’re about to graduate from the University of Melbourne with a double degree in mechatronics and computer science after seven years on the books.
Do you: a) take one of the hundreds of job offers that have come your way in the past two years; b) leapfrog into a career in academia, courtesy of your high profile; or c) start a company that makes bionic arms for people with disabilities?
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Option C, says 24-year-old Robogals founder Marita Cheng, who’s preparing to throw herself full-time into 2Mar Robotics, the start-up she launched in April, when she graduates at the end of the year.
Her vision is to produce a bionic arm which can be used as daily living aid for people with limited hand movement, due to spinal injuries and disabilities such as multiple sclerosis and Parkinson’s Disease. The arm can be mounted in multiple places around the home, including the kitchen and bathroom, and is controlled by iPhone.
“I really wanted to make a robot that was useful to people and changed people’s lives and this was a way I could do it,” Cheng says.
The idea drew enthusiastic feedback from the Spinal Injuries Association when first mooted, Cheng says: “People thought it was a dream come true.”
There are 20,000 people with spinal injuries in Australia and around three million worldwide. As well as offering people more independence, investing in robotic devices makes sound economic sense, Cheng says.
Her arm may reduce the amount of human assistance some people need to perform basic tasks and save thousands in carer costs, she says.
Cheng’s first group of users will begin testing a prototype in their homes next month and she hopes to have the arm available commercially by April next year.
Pricing is yet to be determined but Cheng hopes to collaborate with not-for-profits which can provide grant funding to suitable recipients.
“I feel really lucky, I know what I’m doing next year…I’m looking forward to it, I can spend more time on this,” Cheng says.
Striking out on her own, rather than fast tracking into an international firm, seems a logical progression for someone who cites Steve Jobs as an inspiration.
“I got so many job offers last year, it was a real dream but I always knew I wanted to start a company,” Cheng says.
“I have energy and I like to put that energy into something…I like having a vision and making it happen in real life.”
Jamie Evans is the academic whose suggestion Cheng do something to encourage young girls into engineering led her to found Robogals in 2008. The organisation, which sends students into schools to teach girls robotics, has 17 chapters in four countries and has run workshops for 11,000 girls.
Now the head of electrical and computer systems engineering at Monash University, Evans says Cheng’s segue into the start-up world is no surprise.
“She is a quintessential entrepreneur – someone who is not interested in finding reasons that things can’t be done but rather believing that something is important and making it happen, regardless of the limited resources at her disposal,” Evans says.
“She likes to set her own agenda and, given the amazing things she has already achieved, I could not imagine her taking a graduate job in a big company. I see her as a serial entrepreneur moving from one venture to another over the years.”
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