Years ago I got a free 23 and Me genetics test, and at the time the big news was that they could tell you whether you have the genes that increase your risk for breast cancer and for Alzheimer’s. It was controversial because they didn’t want people learning this information with no context, which might make them panic for no reason (or think that not having the genes means they never have to worry about those illnesses).
For the record, I didn’t have those gene mutations, and it was a huge relief even though I know that genes are not destiny and our lifestyle matters. But knowing something logically doesn’t mean it’s always easy to internalize — as humans, we have a natural desire to want to have control over our destinies, and we will push back against anything that seems like it’s going to take that away.
Which brings me to this headline I read recently in The Guardian: “Lifestyle changes could delay or prevent 40% of dementia cases – study.” The article states, “while some risk factors for dementia cannot be changed, for example particular genes or ethnicity, many are down to lifestyle.” A study co-author told the paper, “Dementia is potentially preventable – you can do things to reduce your risk of dementia, whatever stage of life you are at.”
That is amazing news! Dementia is a horrific illness. Or, I should say, illnesses — “dementia includes Alzheimer’s (the most common type of dementia) but also includes things like Huntington’s and Parkinson’s dementia. Many of these disorders basically steal a person away in front of you — their body is fine but the thing that makes them them dies bit by bit. It’s awful. Any research that helps us understand how it happens and how we can prevent it is essential.
And this is good research. It comes from the Lancet Commission on dementia prevention, intervention, and care, which previously convened in 2017 and reviewed the literature to come up with nine potentially changeable risk factors for dementia: less education, hypertension, hearing impairment, smoking, obesity, depression, physical inactivity, diabetes, and low social contact. They got back together and looked at even more research that has been done, finding that there was even more evidence for their initial nine risk factors and also found there were three other factors: excessive alcohol consumption, traumatic brain injury, and air pollution.
You may already see the small issue I have here — The Guardian’s headline and much of the article make it sound like it’s all in the hands of the individual to prevent their dementia, and of course outlets like the Daily Mail are even worse, offering up “delicious recipes to help beat” dementia and saying that whether or not you get the disease isn’t just up to fate. This is in a way a hopeful message — we want to have control over our health. We want to be able to say “here are the steps I can take to protect myself.” But that’s a problem if it’s a false hope — if we don’t really have that much control, which means we can do everything right and still get dementia. And it can be a problem if we read this and then have less sympathy because the people who get dementia somehow deserved it, because they could have done X, Y, and Z to prevent it. Kind of how some people look at lifelong smokers who get emphysema or lung cancer: well what did they expect? They did it to themselves.
In this case the research itself seems very careful to not do that, highlighting the fact that these “lifestyle factors” aren’t necessarily easy to change for many people. “Our new life-course model and evidence synthesis has paramount worldwide policy implications,” the researchers write. “Culture, poverty, and inequality are key drivers of the need for change. Individuals who are most deprived need these changes the most and will derive the highest benefit.”
For instance, early childhood education is a risk factor, but no children get to decide whether or not they get an education. As much as the Daily Mail wants to convince their readers, this is still a risk factor that is left up to fate. Did you get born into a wealthy family that valued education? A wealthy society that valued education? Or were you born to a poor family in Alabama? And what about air pollution? If you have enough money you can move to a place with good air quality but for most of the planet, whether you end up getting born in Melbourne or Mexico City is just a matter of fate.
Another risk factor is “hearing impairment” — not only is it fate whether or not you’re born with hearing problems, but it’s also fate whether you are in a country with accessible healthcare to treat the impairment, or a country with workplace health and safety standards to make sure you have hearing protection in jobs that require it.
I don’t want to take away all the good news that dementia is something that you can work to prevent. There are things that most all adults can do, like eat fewer calories if you’re overweight which would lead to a lower incidence of type 2 diabetes. Combining that with an increase in physical activity would knock off another risk factor plus would help with depression. And of course, stop smoking and drinking to excess.
While those are all lifestyle changes that most people can do, it’s not easy. Quitting smoking or drinking or overeating can be extremely difficult, and many people don’t have access to treatments that can help, or even to educational resources to let them know how dangerous those activities are. Increasing physical activity is especially hard in places where people need to work 40 or more hours per week, where people drive everywhere, where they don’t even have safe sidewalks to stroll down, or where the air quality is so bad that you can’t be outside for long without increasing another major risk factor.
These are all things, though, that can be helped through social policy change. And that’s why the true conclusion of this research isn’t “you, personally, can prevent dementia.” It’s “you, personally, may be able to take certain steps to keep your brain healthy and you definitely can vote for politicians who will keep their constituents healthy by easing income inequality, providing affordable healthcare for everyone, and making sure everyone has access to education from childhood through adulthood.