According to recently released data from the U.S. Department of Health and Human Services, access to health insurance has led to a growing gap between the life expectancies of the rich and poor.

As it's reported by MSN Health, this disparity in life expectancy has almost doubled between more affluent Americans and the nation's poorest residents over an 18-year period, with residents at top income levels living an average of 4.5 years longer than the poorest Americans.

And foremost among the reasons for this gap is access to health insurance.

But the truth is that while medical coverage is listed among the four main reasons for the earlier death of poorer Americans, access to health insurance impacts all of the reasons listed for the gap. People with insurance enjoy regular checkups with their doctors, and as such, are more aware of modern treatments for disease, are advised not to smoke by their doctors, and are also more likely to receive dietary advice from medical professionals.

All of which means that access to health insurance offers perhaps the biggest impact upon the health and well-being of all Americans today, rich or poor.