You're never too old to stop smoking. Whether you're 60, 70 or 80, a just published study shows that your short-term risk of death drops by about 27% once you quit. And the increased risk that came because you've been smoking drops by nearly 60%.

Investigators from the German Cancer Research Center analyzed data from 17 previous studies done in seven countries and published between 1987 and 2011. The studies in this meta-analysis compared the number of deaths of smokers, non-smokers and former smokers over various lengths of time, with follow-ups ranging between three and 50 years.

Some studies simply looked at the number of deaths over one certain time period, while others looked at several different time periods. What all the studies had in common was that they all contained mortality data for people 60 years or older.

When information from all the studies was averaged, it showed that smokers 60 and older had an 83% higher risk of death than non-smokers of the same age, over whatever time period was being looked at in an individual study. Presumably, this 83% increase represents the additional deaths that are caused by smoking. But the increase was only 34% for former smokers. Much of the risk went away once people stopped smoking.

The results also showed that the benefits of quitting smoking increased as time passed: the longer since a person had quit, the greater was their drop in mortality risk.

The drop in death rate from quitting was similar for those in their 60s, 70s and in their 80s.

The study only concerned itself with death. It didn't look at the better life that comes once you stop smoking. The carbon monoxide in cigarette smoke replaces a lot of the oxygen that normally is carried by the hemoglobin in the blood. This means that the muscles and the brain don't get nearly as much oxygen as they should. How nice would it be to be able to take a walk without getting tired? Or to be able to think clearly again?

It's not too late to stop smoking. No matter how old you are, there's plenty left to gain.

An article on the study appears in the Archives of Internal Medicine. Also appearing in the same issue is a commentary which discusses what the numbers in the study mean to an individual smoker.