TORONTO – There has been a lot of media attention about Alzheimer’s disease lately, with Julianne Moore winning the best actress Oscar for her role as a woman going through early onset Alzheimer’s disease in the movie Still Alice.
And many of us have seen ads for websites that offer “brain games” and “brain training,” which many people use in the hopes of preventing Alzheimer’s dementia. So I thought it would be useful to look at the scientific evidence around these kinds of websites.
Alzheimer’s is the most common form of dementia, it’s seen in about seven per cent of people over the age of 60, and the incidence of dementia doubles every 10 years after age 60. Because we don’t have good treatments for it, we certainly would love to be able to prevent it.
The concept behind these brain exercises is that even in adulthood, our brain maintains a degree of what we call “neuroplasticity,” which is an ability for our neural pathways to adapt and change with changing circumstances, including training.
What this training might do is give us a degree of what we call “cognitive reserve” – whereby if you start off with a “reserve” of higher brain function, then the manifestations of Alzheimer’s might be delayed and/or less severe.
A 1994 study by Y. Stern and colleagues in The Journal of the American Medical Association has shown that people with higher levels of education have a reduced risk of Alzheimer’s. Autopsy and PET scanning studies (DA Bennett and colleagues in Neurology in 2003, and V Garibotto and colleagues in Neurology in 2008, respectively) show that for the same amount of actual brain disease, people with more education have milder symptoms of Alzheimer’s. Accordingly, the notion is that if you train your brain, although you might not prevent the actual Alzheimer’s, you might be able to delay or reduce its effects.
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And several studies have looked at the short term training impact of these websites. A 2014 review in PLoS Medicine by A Lampit and colleagues looked at 51 studies with about 5,000 healthy older adults who used these websites and other such programs (so called “computerized cognitive training”).
They found small but statistically significant improvements in memory, processing speed, and visuospatial skills. The caveat is that not all studies were positive, and more research is needed to figure out the best type of program and how it should be delivered. Unsupervised home-based training did not seem to be effective compared to group training, training is not effective if given more than three times a week, and sessions lasting less than 30 minutes seem to be less effective.
Also, we don’t know if these short term improvements will last, and whether they will translate into reduced rates of dementia.
So although we don’t yet have any evidence on what works to prevent Alzheimer’s, we do know that certain things are associated with Alzheimer’s, and hopefully studies will eventually show that modifying these risk factors can actually prevent the disease.
Five risk factors for Alzheimer’s dementia
Genetics
Unfortunately, this one is not modifiable. But aside from age, genetics is the most clearly established risk factor for Alzheimer’s. Patients with a first-degree relative with dementia have a 10 to 30 per cent increased risk of developing Alzheimer’s. Although the early-onset (age less than 65) form of Alzheimer’s accounts for less than one percent of cases, it is associated with specific genetic mutations, and children of parents who have this will almost certainly get it too.
High cholesterol
Observational studies show an association between elevated LDL or total cholesterol at midlife and the risk of Alzheimer’s. In 2002, M Kivipelto and colleagues showed in the Annals of Internal Medicine that a high total cholesterol at an age of about 50 confers a three-fold higher odds of developing Alzheimer’s later in life.
High blood pressure
Midlife hypertension has also been consistently associated with risk of Alzheimer’s later in life.
Obesity and Diabetes
Obesity and diabetes each confer about a 1.5 fold increased risk for Alzheimer’s. It’s important to note that the above risks, including high cholesterol, high blood pressure, obesity and diabetes are all “vascular” risk factors – the same things that cause strokes, and are associated with what we call “vascular dementia,” related to multiple small strokes. However, all of these have also been independently associated with Alzheimer’s dementia.
Inactivity
Studies suggest that people who are physically active have about a 45 per cent reduction in the risk of developing Alzheimer’s compared with those who are less active (M Hamer and colleagues in Psychological Medicine, in 2009), even after adjusting for all those other risk factors.
And the bonus is that being active in itself addresses the rest of those risk factors, including elevated blood pressure, cholesterol, obesity, and diabetes, among its many other benefits.
So if one had to choose between sitting around and playing with these websites and actually doing exercise, I would recommend the exercise.
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