Study Links Autism To Environmental Factors: Here’s Why You Should Care

Newsrooms were slow over the holiday, but one headline that stood out this weekend was all about a new study linking autism to environmental factors. Before you close this window because you’re not autistic, don’t know anyone who’s autistic, or don’t have kids who could be autistic, continue reading: You should have more than a passing interest in this study. It’s caused a big shift in thinking about factors that cause autism, convincing many that it’s not just genetics, but environmental factors that could be at fault for the disease. While they aren’t sure exactly which environmental factors are linked to autism, I think the study provides a modicum of hope for anyone who faces health problems (which means all of us, at some point or another).

Instead of assuming that diseases — behavioral or otherwise — are just an irreversible fate that’s hard-coded into our genes, there’s good reason to believe that what we eat, drink, breathe, do, and think all have an impact on how our health turns out. And those are all things we have a lot more control over than the what we inherit from mom and dad.

The research, published online in the Archives of General Psychiatry and led by Dr. Joachim Hallmayer, a psychiatrist at the Stanford University School of Medicine, concluded that environmental factors may account for as much as 55 percent of autism risk, while genetic causes account for less than 40 percent. They determined causes by analyzing a group of fraternal twins and a group of identical twins, in which at least one sibling was diagnosed with autism. By comparing the rates of diagnosis in fraternal twins (whose genes were only as similar as any siblings) vs. identical twins (whose genes are exactly the same), they could determine whether autism was caused by genes or shared environmental factors.

Neil Risch, director of the Institute for Human Genetics at University of California San Francisco and senior author on the paper, explained:

It’s not either-or in terms of genetics or environment. We’re not saying autism isn’t genetic, because the huge majority of twins don’t have autism. Obviously something is priming the risk, and it looks like that may be a genetic predisposition. So a genetic base and environmental factors together may explain autism better.

The study didn’t outline exactly which environmental factors are at play; in fact, researchers specified that they don’t know if shared environmental factors are in utero or post-birth. Other recent studies have linked autism to antidepressant use during pregnancy, vaccinations, food coloring, and household chemicals.

On the one hand, studies like this are scary: There’s something we’re doing — en masse, if the dramatic rise in autism in recent years is any indication — that’s making us sick and making our kids sick. But on the other hand, I think it’s hopeful: If we can figure out what we’re doing that’s making us sick, we can control it. And for a number of health problems plaguing the population today, we have figured out which things we do are contributing to our disease: eating unhealthy foods, not exercising enough, smoking, drinking, not sleeping enough, and being constantly stressed. The solution isn’t easy; drastically changing your lifestyle never is. But it’s a lot easier than changing our genes.

Whenever there’s a study telling us that our behavior could cause disease, or an expert tells us that eating or drinking certain foods could prevent disease, there are always people to counter their ideas with the strong evidence to the contrary: “I’ve been smoking a pack a day for 40 years and I still don’t have cancer,” someone will say, or: “I drink coke every single day and I’m not fat.” And then there are tragic stories about people who ran marathons, ate only healthy salads and whole grains, and still ended up in the hospital with a disease. Some take this as evidence that no matter what we do, we’ll always be beholden to our genes, and there’s not much point in agonizing over exercise or skipping dessert.

But I think that’s a fairly sad, jaded way to look at things, and more importantly: You’re missing out on a good opportunity to feel empowered and in control. Yeah, most health advice doesn’t come with a 100% certain, cash- and time-back guarantee: There are some studies that turn out to be flat-out wrong, and even taking widely accepted health advice doesn’t always secure you a long, disease-free life. There are the Lance Armstrongs of the world, and frankly, it sucks. But when there’s overwhelming evidence that eating fruits and vegetables makes you healthy, and working out wards off disease, then why not do it every once in awhile?

If there are small things we can tweak about our behavior or environment that can increase risk for autism, then there are small things we can tweak that will decrease risk, too. I think that’s good news for all of us.

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