smoking and health: an update

2011 Johns Hopkins Bloomberg School of Public Health

Jonathan M. Samet, MD, MSDirector, USC Institute for Global Health Professor and Flora L. Thornton Chair, Department of Preventive Medicine Keck School of Medicine

Smoking and Health: An UpdateSmoking and Health: An Update


Global Tobacco EpidemicGlobal Tobacco Epidemic

State of the global tobacco epidemic and an update on the health effects of smoking

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Prevalence of Current Cigarette Smoking

*GATS = Global Adult Tobacco Survey

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The 2010 Report of the U.S. Surgeon General

Reviews mechanisms by which smoking causes disease

Includes findings from human, animal, and laboratory studies

Evidence important for causation, prevention, diagnosis, and treatment

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Text and image source: USDHHS. (2010).


SGR 2010: Major Conclusions

Source: USDHHS. (2010).

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SGR 2010: Summary on Genetics of Nicotine Addiction

Source: USDHHS. (2010).

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Emerging Information on the Health Effects of Smoking

Tuberculosis

Breast cancer

Diabetes mellitus

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Smoking and Tuberculosis

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Risk of Latent TB Infection for Smoking vs. Nonsmoking

Image source: (2007). PLoS Med, 4:e20

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Risk of Clinical TB for Current Smoking vs. Nonsmoking


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Risk of TB Mortality for Smoking vs. Nonsmoking


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Mortality risk ratio* (99% CI)

Smoking-attributable

risk

Men 2.3 (2.1-2.6) 38 %

Women 3.0 (2.4-3.9) 9 %

*RR comparing smokers to nonsmokers, adjusted for age, education, and alcohol

Deaths due to tuberculosis among Indian adults ages 30-69 years

Estimated excess smoking-associated deaths among Indian adults in 2010

Number of excess TB deaths

Men 120,000 of 315,000

Women 14,000 of 155,000

Source: Jha et al. (2008). NEJM, 358, 1137-1137.

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Tobacco Smoking/SHS Exposure and Breast Cancer Risk

Source YearStudies

reviewedConclusions

International Agency for Research on Cancer (IARC)

2004

Active smoking:

36 case-control studies, 8 cohort studies, 1 large pooled analysisSecondhand

smoke: 10 case-control studies, 5

cohort studies

Active smoking:There is evidence suggesting lack of carcinogenicity

of tobacco smoking in humans for cancers of the female breast and endometrium.

Secondhand smoke:The collective evidence on breast cancer risk associated with involuntary exposure of never

smokers to tobacco smoke is inconsistent.

U.S. Surgeon General’s Report

200417 case-control

studies, 5 cohort studies

Active smoking:The evidence is suggestive of no causal relationship

between active smoking and breast cancer.

Subgroups of women cannot yet be reliably identified who are at an increased risk of breast cancer because of smoking, compared with the

general population of women.

Whether women who are at a very high risk of breast cancer because of mutations in BRCA1 or

BRCA2 genes can lower their risks by smoking has not been established.

U.S. Surgeon General’s Report

200614 case-control

studies, 7 cohort studies

Secondhand smoke:The evidence is suggestive but not sufficient to

infer a causal relationship between SHS and breast cancer.

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Tobacco Smoking/SHS Exposure and Breast Cancer Risk

Source YearStudies

reviewedConclusions

Cal/EPA 200626 studies

(including 3 meta-analyses)

Secondhand smoke:Human epidemiological studies, supported by the

fact that at least 20 of the chemical constituents of ETS are mammary carcinogens, provide evidence consistent with a causal association between ETS exposure and breast cancer in younger primarily

premenopausal women.

There is little, if any, evidence of an increase in breast cancer risk in older primarily

postmenopausal women.

Canadian Expert Panel on Tobacco Smoke and Breast Cancer

2009

Active smoking:7 reviews and 4 meta-analyses Secondhand

smoke: 5 reviews and 4 meta-

analyses Genetics and

active smoking:3 meta-analyses

Active smoking:Based on the weight of evidence from

epidemiologic and toxicological studies and understanding of

biological mechanisms, the associations between active smoking and both pre- and postmenopausal

breast cancer are consistent with causality.

Secondhand smoke:The association between SHS and breast cancer in

younger, primarily premenopausal women whohave never smoked is consistent with causality. The

evidence is considered insufficient to passjudgment on SHS and postmenopausal breast

cancer.16


Smoking and Diabetes

Image source: Willi et al. (2007). JAMA, 298, 2654-2664.

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Smoking and Diabetes

Image source: Willi et. al. (2007). JAMA, 298, 2654-2664.

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Menthol CigarettesMenthol Cigarettes

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A report of the FDA’s Tobacco Products Scientific Advisory Committee (TPSAC)


Menthol Cigarettes

Menthol is an organic compound (a naturally occurring monocyclic terpene alcohol), either derived from natural sources or synthesized, widely used in consumer and medicinal products

Pharmacologically, menthol in cigarette smoke has a cooling effect that may facilitate deeper inhalation and mask the irritation by nicotine and other smoke components

Menthol is present in most cigarettes in the United States, and in about 30% of cigarettes it is present in high enough concentration to make menthol the characterizing flavor

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Menthol Cigarettes

The FDA is charged with addressing the impact of the use of menthol in cigarettes on the public health Its scientific committee developed a report on this

topic, released in March 2011

Menthol cigarettes are not common worldwide, but products are being developed

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Menthol: Possible Effects on Public Health

Image source: Tobacco Products Scientific Advisory Committee (TPSAC), FDA. 2011

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TPSAC Conclusions:

Based on the conclusions to the nine questions, TPSAC provides the following general conclusions:

Menthol cigarettes have an adverse impact on public

health in the United StatesThere are no public

health benefits of menthol compared to

non-menthol cigarettes

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TPSAC’s Recommendation to FDA

Removal of menthol cigarettes from the marketplace would

benefit public health in the United States

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smoking and health: an update

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