Washington (CNN)Retired neurosurgeon Ben Carson apologized for commenting Wednesday that prisoners' changes after they leave jail proves being gay is a choice, but said that the science is still murky on the issue. In a statement, Carson said he "realized that my choice of language does not reflect fully my heart on gay issues." "I do not pretend to know how every individual came to their sexual orientation. I regret that my words to express that concept were hurtful and divisive. For that I apologize unreservedly to all that were offended," he added.