Smoking

The Relationship Between Smoking Patterns and Mortality Risk

The relationship between smoking and mortality is complex, with risk varying based on smoking pattern, product type, duration, cessation timeline, and exposure to passive smoking. Current scientific evidence demonstrates that all forms of smoking increase mortality risk compared to never smoking, but with important variations.

Traditional Cigarette Smoking and Mortality

Daily Smoking

Daily cigarette smoking presents the highest mortality risk among common smoking patterns:

Current smokers have significantly elevated risk for major cause-specific mortalities compared to never smokers, including cardiovascular diseases (HR 3.42), pulmonary disease (HR 8.27), and lung cancer (HR 16.43)¹
Among smokers who died, 13.7% died before age 65, compared with only 8.3% in never smokers¹
Heavy smokers (≥1 pack/day) have the highest mortality risk compared to light and former smokers¹

Occasional and Light Smoking

Despite consuming fewer cigarettes, occasional and light smokers still face substantial mortality risks:

Intermittent male smokers have significantly increased all-cause mortality risk (OR 1.6) compared to non-smoking men²
Low-rate smokers (1-4 cigarettes/day) show relative risks for all-cause mortality of 1.6 in men and 1.5 in women²
Light smoking results in a 4-6 year median loss of life compared to non-smoking women²
Cardiovascular risk is disproportionately high with light smoking, with low levels of tobacco exposure (4-7 cigarettes/day) having about 70% of the effect of heavy smoking²
Even occasional smoking among men is associated with increased risk of cardiovascular mortality (RR 1.5) compared to non-smoking men²

Waterpipe (Shisha/Hookah) Smoking

Waterpipe tobacco smoking is associated with significant mortality risks:

Individuals who smoke tobacco using a waterpipe have higher risk for death from multiple cancer types compared with never smokers³
Waterpipe smoking significantly increases mortality risk specifically from liver, lung, nasopharyngeal, and stomach cancers³
Notably, smoking waterpipe tobacco exclusively increases risk for cancer death more than smoking cigarettes only³
The charcoal used to heat tobacco produces high levels of carbon monoxide, metals, and cancer-causing chemicals³
Even after passing through water, hookah smoke contains high levels of toxic agents³

Smoking Cessation and Mortality Risk Reduction

Quitting smoking progressively reduces mortality risk over time:

1-5 Years After Quitting

Heavy smokers' mortality risk can be reduced by 44% within the first decade of quitting¹

5-10 Years After Quitting

Risks of dying from cerebrovascular disease, sudden death, and colorectal cancer return to the level of never smokers within 10 years of quitting¹
Smoking cessation for at least 10 years significantly reduces overall mortality risk³

10+ Years After Quitting

Risk for smoking-related cancers (excluding lung cancer) returns to never-smoker levels after 10 years¹
Coronary heart disease, pulmonary disease, and lung cancer risks approach never-smoker levels after 20 years¹
Prostate cancer risk requires approximately 30 years of cessation to normalize¹
Light smokers' mortality risk returns to never-smoker levels after 10 years (versus 20+ years for heavy smokers)¹

Age-Related Cessation Benefits

Quitting before age 44 results in mortality only 21% higher than never smokers⁴
Quitting between ages 45-54 still shows substantial benefit compared to continuing smoking, though mortality remains 47% higher than never smokers⁴

Never Smokers and Baseline Risk

Never smokers have the lowest mortality risk:

The lowest overall mortality rate is observed in non-smokers without coronary artery calcification (0.7 events per 1,000 person-years)⁵
Mean 5.6-year all-cause survival is 99.6% for non-smokers with zero coronary artery calcification⁵
Never smokers serve as the baseline comparison group, with all smoking patterns showing elevated mortality risk relative to this group¹²⁵

Passive Smoking and Mortality Risk

Passive smoking (secondhand smoke exposure) significantly increases mortality risk:

Passive smoking is associated with increased risk of all-cause, cardiovascular-related, and cancer-related mortality⁶⁷
It shows a synergistic effect with active smoking status on mortality risk⁶⁷
Current smokers who are also exposed to passive smoking have the highest risk of all-cause and disease-specific deaths⁶⁷
According to WHO, passive smoking was responsible for 1.5 million deaths from chronic respiratory diseases in 2017⁷
The accumulation of cadmium in the blood due to smoking and passive smoking mediates increased all-cause mortality risk⁶⁷

Conclusion

All smoking patterns—traditional cigarettes (daily, occasional, or rare), shisha/waterpipe, and likely electronic cigarettes—increase mortality risk compared to never smoking. While daily smoking presents the highest risk, occasional and light smoking still significantly increase mortality. Shisha smoking shows particularly concerning cancer mortality risks that may exceed cigarettes in some cases.

Quitting smoking progressively reduces mortality risk over time, with different disease risks normalizing at different intervals, ranging from 10 to 30 years after cessation. Never smokers have the lowest mortality risk, while passive smoking significantly increases mortality risk, especially when combined with active smoking.