Could living in a major city increase your risk of dementia? A new study suggests that may be the case.

After studying over two million Ontarians over an 11-year period, researchers found that the closer they lived to a major roadway, the more likely they were to develop dementia. Those who had lived in urban areas for a long time were even more likely to develop the condition than those who had moved more recently.

These findings suggest one culprit in particular: air pollution. Of course, the study didn’t prove that air pollution causes dementia – only that there is some sort of relationship. But this isn’t the first major study to find an association between air pollution and a decline in brain function in middle-aged and older adults.

So does this mean that we should all flock to the country? Not so fast.

The increased risk shown in the study is only slightly higher, and while these results might help us understand a bit more about what causes dementia in certain circumstances, more research needs to be done.

The “brew” of different toxins that make up air pollution make it difficult to attribute the effect to one specific factor, and there are other factors besides air pollution that may come into play.

Yet, air pollution is an area worthy of more study because it has other indirect but very important effects on the brain. Air pollution may contribute to conditions like pulmonary disease, heart disease and stroke, which we know can increase a person’s chances of developing dementia. Cardiovascular disease, in particular, can lead to vascular dementia.

While the findings of this new study are preliminary, they do have important implications for public health. We need to do more to control and reduce air pollution and protect our most vulnerable citizens.

And while we still don’t fully understand the causes of dementia, there are things we can do right now to reduce our risk. More physical activity, eating a heart-healthy diet, quitting smoking, challenging our brains and staying socially connected are all essential for brain health.