By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) - There is a major study in the British Medical Journal taking a look at cigarette smoking and long term effects. There is the expected news. Cigarette smokers have a dramatic increase in the risk of heart attack, stroke and a wide variety of cancers.

There is also no dispute that if you are a cigarette smoker you are not the only one at risk. Those exposed to passive smoke are at significant risk as well. But, what about quitting?

According to the Japanese study of 68,000 men and women, those who quit before age 35 had the same risks of future problems as those who never smoked.

The message is clear, the earlier you quit the better your chances of reducing damage.

One final point not in the study but something I want to stress. If you have tried to quit in the past and failed, do not get discouraged. The next patient who comes to my office who has not failed in a prior attempt will be the first.