Posted Tuesday, August 14, 2012 --- 3:30 p.m.

DALLAS (AP) -- Here's another reason to know your blood type -- it might be a clue to your risk of heart disease.

New research shows people who have blood types A, B or AB have a slightly higher risk of heart disease compared to those with O, the most common kind of blood type.

Harvard researcher Dr. Lu Qi says those who know they are at higher risk may be more motivated to make changes to lower their chances of heart disease.

But a doctor not involved in the study notes that the increase was modest, and that other things like smoking have a bigger impact on risk.

The study was published Tuesday in a journal of the American Heart Association.

Copyright 2012. The Associated Press.