Warning: Habits and poor health in midlife can shrink your brain

Pop quiz: Which of the following causes the brain to shrink?

1) diabetes

2) smoking

3) high blood pressure


4) being overweight in middle age?

Answer: All four. That’s the latest word from the famous Framingham Heart Study, an investigation of residents of a Massachusetts town that’s been going on since 1948.

This particular report, published in the journal Neurology, tracked 1,352 people with an average age of 54 for years. All were offspring of the original set of Framingham residents who agreed to join the study. They had their risk factors assessed at mid-life. Then, between ages 61 and 67, their brain structure was assessed via MRI scanning. They also had cognitive tests.

Brain shrinkage was linked to all four risk factors, though the pattern differed in each case. People with high blood pressure, for example, developed “white matter hyperintensities,” -- basically places in the brain’s white matter where damage is occurring -- at a faster clip than others did. And those who had diabetes in midlife had more rapid shrinkage of the hippocampus, part of the brain that’s crucial for memory. If you smoked, the whole brain shrunk more than if you didn’t. Ditto for being overweight. And more.

None of it sounds especially good.

The authors also found decline in the brain’s “executive function” in these groups – basically, how well the brain performs its tasks of thinking and attending to things.

More details are in the paper (you can read the abstract for free, at least).

The finding isn’t exactly a shocker, because smoking, hypertension, obesity and diabetes all increase the risk of damage to the cardiovascular system. And studies have shown that damage to the cardiovascular system is linked to risk for dementia (there is a whole category of dementia called vascular dementia, after all), and even Alzheimer’s disease is thought in many cases to be mixed in nature, with some vascular contributions.


But there’s something quite graphic about capturing actual damage with brain scans. And, as the authors note in the study, “most of these risk factors are modifiable by validated treatments and lifestyle changes.”

Of course, it’s not easy to get people to muster up the willpower to make lifestyle changes –lose weight! Stop smoking! Get exercise! --but nobody especially wants to hear that their brain is getting smaller. Being told you can stop your brain from shrinking might, perhaps, add extra clout to that pep talk in the doctor’s office about the need to drop pounds and find a way to deal with stress.

By the way, if you’re curious about the Framingham study, check out this list of key findings the study has made through its north-of-60 years and north-of-1,000 studies. From a 2009 L.A. Times article written by freelancer Amber Dance:

* 1960: Smoking increases risk for heart disease.


* 1961: High cholesterol and high blood pressure are risk factors for heart disease.

* 1967: Obesity increases one’s chances for heart disease; exercise reduces risk.

* 1970: High blood pressure increases risk of stroke.

* 1976: Risk for heart disease in women increases after menopause.


* 1998: The Framingham Heart Study publishes its cardiovascular risk calculator to estimate a person’s chances of developing heart problems within the next decade.”