Here's one ratio that doesn't quite add up mathematically. If you cut down on smoking, you still do not cut down the harms associated with it.

This is the conclusion of a study conducted regarding the impact of cutting down smoking on deaths from heart disease, lung cancer and other tobacco-related cancers. The study took a 20-year follow up period, and had participants between 20 to 34 years old. Says Dr. Kjell Bjartveit, former director of the National Health Screening Service in Oslo, " The long-term effects of a substantial reduction in smoking did not show any benefits in comparison with persistent heavy smoking."

Therefore, don't get to thinking that just because you cut back from 15 sticks of cigarettes a day to only seven, you'd also be cutting down to half the risk of you dying of smoking-related causes.

So, follow the doctor's advice: "Smokers should quit -- you can't give your health a better present than to quit smoking."