There are so many convincing reasons to stop smoking that you may not need to hear about this new one: Kicking the smoking habit can reverse the stiffening of your arteries. But perhaps if you're still smoking, this additional reason will finally get you to do something about this dumb habit.

Cigarette smoking is a major risk factor for the development of the atherosclerotic plaques that lead to heart attacks. But it's been known for many years that this effect wanes progressively after you stop smoking.

It's also been known for a long time that systolic blood pressure (the top number) tends to rise as people age, as the aorta and other large arteries become less flexible. Cigarette smoking also leads to stiffening of the arteries and further elevation of the blood pressure.

Here's the surprising good news: Blood vessels gradually regain their flexibility after people stop smoking. In a recent study published in the journal Hypertension, arterial stiffness fell progressively in relation to the last cigarette smoked.

However, the study also found that it might take as long as 10 years to reverse this effect of smoking, so kicking the habit earlier rather than later is also important. Although it is likely that improving the elasticity of arteries will lower systolic blood pressure, the present study did not address that issue.

Another study found that even smoking a single cigarette was associated with an increase in arterial stiffness, so that blood pressure and heart rate rose almost immediately after smoking a cigarette — and they rose once again with each additional cigarette consumed. Blood pressure and heart rate increased most with the first cigarette smoked in the morning, a time when heart attacks are known to be most frequent.   

These effects of smoking, which are both rapid and long-term, on arterial stiffness and blood pressure should serve as yet another incentive to stop smoking. And the sooner the better.