How many years shorter is the average life expectancy for a smoker compared with a non-smoker?

• A. 5 years
• B. 10 years
• C. 15 years
• D. 20 years

Answer: (B)

Smoking increases the risk of heart disease, stroke, chronic obstructive pulmonary disease, and many cancers, so it shortens overall lifespan on average. Large studies comparing smokers and non-smokers consistently show about a ten-year difference in life expectancy, with non-smokers living about a decade longer. That makes ten years the best estimate for the average shortfall. The smaller option underestimates the typical gap, while the larger ones overstate the average difference—though individual cases vary. Quitting can reduce risk and restore some life years, especially if done earlier, as the body gradually returns toward the risk profile of a non-smoker.