We tend to attribute strokes and heart attacks to genetic factors and adult behaviors. Yet there are some clues that the groundwork for cardiovascular troubles is laid early in life—perhaps even before birth, reports the February 2010 issue of the Harvard Health Letter.

Residents of North Carolina, South Carolina, Georgia, Alabama, Mississippi, Arkansas, and Tennessee are up to 50% more likely to die from a stroke than those who live elsewhere. This area has come to be called the Stroke Belt. Harvard researchers believe that early life influences, not just adult behaviors, help explain what is happening in the Stroke Belt.

In one study, M. Maria Glymour, an assistant professor at the Harvard School of Public Health, and her colleagues found that people who lived in the Stroke Belt as children but who moved away were 25% more likely to have had a stroke in adulthood than those who had never lived there, and that their risk was actually a bit higher than that of people who lived in the region as both children and adults. In a follow-up study published late last year, Glymour and colleagues found similar results. This time, though, people with “double exposure”—birth and adulthood in the Stroke Belt—had a higher stroke death rate than people who were born in the Stroke Belt but moved away, or who moved there after being born elsewhere.

What kinds of early life exposures might increase the chances of having a stroke later on? British researchers have zeroed in on low birth weight, poverty, and poor maternal health. Conditions in the womb may affect how a child's blood vessels develop or change his or her inflammatory response. Later on, the circulatory system is almost certainly affected by a child's diet, environmental exposures, even psychological stresses.

This research doesn’t mean we should give up on prevention in adulthood, notes the Harvard Health Letter. But it is yet another reason to think of lifestyle changes during adulthood as risk reducers, not as efforts that will wipe the slate entirely clean.

Read the full-length article: "Does stroke risk begin with the stork?"