Vaping vs Smoking: Systematic Review with ☸️SAIMSARA.

• Generated: 2025-12-10 13:01:43 CET
• Plan: Premium (expanded craft tokens; source: Europe PMC)
• Source: Europe PMC
• Scope: Titles/Abstracts (tiab)
• Keyword Gate: Fuzzy (≥60% of required terms, minimum 2 terms matched in title/abstract)
• Total Abstracts/Papers: 2179
• Downloaded Abstracts/Papers: 2179
• Included original Abstracts/Papers: 1323
• Total study participants (naïve ΣN): 8075212

• Bias: Qualitatively inferred from study design fields. The included studies predominantly feature cross-sectional and cohort designs, which are susceptible to selection bias and confounding, limiting causal inference. Randomized controlled trials (RCTs) are present but less frequent, particularly for long-term health outcomes. Many studies rely on self-reported data, introducing potential recall and social desirability biases. Small sample sizes in some studies further limit generalizability.

• Prevalence and Trends: Vaping prevalence increased fivefold (5.0% to 25.0%) among young adults (18-24 years) in England, surpassing smoking prevalence [5, 31]. Cumulative vaping incidence (75.8%) was higher than smoking (60.2%) among Australian adolescents by age 21 [3]. Long-term vaping among adults in England increased substantially from 1.3% to 10.0% [220, 403]. Dual use also increased from 3.5% to 5.2% [60].
• Health Impacts and Toxicant Exposure: Vaping significantly reduced formaldehyde and acetaldehyde levels (99.6-99.9% lower) compared to smoking [48]. Pooled odds ratios (ORs) for vaping versus smoking showed reduced risk for myocardial infarction (MI) (0.48), stroke (0.65), and chronic obstructive pulmonary disease (COPD) (0.46) [53]. However, vaping was associated with reduced birthweight in dual users [1], impaired nasal mucociliary clearance [318], increased regional ventilation delay [155], and similar epigenomic dysregulation in oral cells as smoking [148]. E-cigarette use is associated with chronic kidney disease (OR 2.50) [310] and increased risk of obstructive sleep apnea (OR 2.01) [277].
• Cessation and Relapse: Daily vaping was associated with higher odds of achieving smoking abstinence two weeks later (30.4% vs. 16.3%) [2] and increased quit attempts [316], but also with an increased risk of relapse (adjusted-HR=1.31) [2]. Nicotine e-cigarettes are more effective for quitting smoking than nicotine replacement therapy (NRT) (RR 1.59) and non-nicotine e-cigarettes (RR 1.46) [888]. Vaping cessation interventions significantly increased 7-day point prevalence abstinence (OR 1.52) and continuous abstinence rates (OR 2.71) [174].
• Perceptions and Social Norms: Perceiving vaping as less harmful than smoking was associated with switching from smoking to vaping [7]. However, misperceptions about vaping harms are common [71, 88, 188, 331], and some young adults switch from vaping to smoking due to perceived health benefits of smoking or greater accessibility of cigarettes [21, 34]. Peer influence is a strong factor in uptake and continued use of both smoking and vaping among youth [45, 20]. Vaping is often normalized, especially disposable vapes [131, 90].
• Mental Health and Comorbidities: Poorer mental health (stress, depression, anxiety) was associated with positive smoking and vaping norms among youth [4]. Higher stress, anxiety, and depression were associated with vaping for tension reduction [162]. Adolescents with severe psychological distress had higher odds of cannabis vaping [265]. Smoking, vaping, and dual use were higher among those with mental health conditions [288]. Vaping cessation was associated with improved quality of life and mental health outcomes [109].
• Policy and Regulation Impacts: Restricting vaping product sales to over-the-counter (OTC) pharmacy access is projected to reduce vaping prevalence and yield net health gains [10]. State restrictions on flavored ENDS sales were associated with reduced daily vaping but may have unintentionally increased daily cigarette smoking among young adults [100, 431]. Household vaping bans were associated with 56% lower odds of youth vaping [219]. Cigarette taxes significantly reduced smoking frequencies [161] and increased abstinence [173], while e-cigarette (EC) taxes had varied effects [173, 329].
• Nicotine Dependence and Exposure: Nicotine salt products were linked to higher nicotine exposure among adolescents, with levels similar to smoking [118]. Vaping dependence tended to decrease over time in long-term users, but reasons for use shifted towards enjoyment and perceived lower danger [311]. Vaping dependence was significantly associated with increased depression symptoms [336]. Quitting vaping is challenging, with 74.2% of young adults having attempted, but less than 2% of successful quitters used FDA-approved cessation aids [24].

• Harm Reduction Strategy: For adult smokers unable to quit with approved therapies, switching to vaping may offer a harm reduction pathway by significantly reducing exposure to key toxicants and lowering risks for cardiovascular and respiratory diseases [48, 53, 202, 879].
• Cessation Support: Nicotine e-cigarettes are more effective than NRT for smoking cessation [888], and healthcare providers should be equipped to discuss vaping as a cessation aid, particularly for smokers with mental health conditions who are more motivated to quit but less likely to succeed [342, 463].
• Youth Risk Assessment: Clinicians should be aware of the high prevalence of vaping among youth, its association with mental health issues, and the potential for dual use or progression to smoking, necessitating targeted screening and intervention [4, 13, 114, 265].
• Pregnancy Counseling: Smoking and dual use during pregnancy are associated with reduced birthweight [1], and while vaping alone showed no impact, the overall risks and perceptions of vaping as healthier during pregnancy require careful counseling [77, 98].
• Oral Health Monitoring: Both smoking and vaping are associated with oral health problems, including periodontal disease, reduced saliva production, and altered oral microbiota, warranting comprehensive oral health assessments for all users [23, 59, 249, 300].

• Long-Term Health Outcomes: Further longitudinal cohort studies are needed to definitively compare the long-term cardiovascular, respiratory, and carcinogenic risks of exclusive vaping versus sustained smoking and non-use, particularly in diverse populations [53, 106, 108, 164, 244, 310, 315, 322, 335, 341, 355].
• Youth Gateway Effect: Prospective cohort studies are required to establish the causal directionality and mechanisms of the "gateway effect," i.e., whether vaping directly leads to smoking initiation or merely reflects common risk factors, especially across different regulatory environments [114, 147, 158, 214].
• Cessation Intervention Efficacy: Randomized controlled trials (RCTs) are needed to evaluate the effectiveness of different vaping cessation interventions (e.g., behavioral therapy, pharmacotherapy like cytisinicline) for exclusive vapers, dual users, and specific vulnerable populations [24, 123, 276, 337, 411, 429].
• Impact of Policy Interventions: Research should investigate the real-world, long-term effects of various policy interventions (e.g., flavor bans, taxation, age restrictions, standardized packaging) on both smoking and vaping prevalence, cessation rates, and unintended consequences like black market growth or switching to more harmful products [10, 100, 139, 161, 173, 215, 258, 291, 313, 329, 404, 431, 422].
• Mental Health and Substance Co-use: Studies should explore the complex interplay between mental health conditions, nicotine vaping, and cannabis co-use, including mechanisms of action and the development of integrated interventions for polysubstance use [4, 20, 35, 39, 41, 64, 66, 69, 80, 87, 99, 113, 117, 128, 162, 166, 178, 211, 226, 231, 234, 238, 245, 246, 265, 283, 288, 293, 305, 320, 321, 325, 336, 342, 347, 360, 364, 373, 388, 393, 394, 401, 405, 417, 438, 449, 452, 506, 617, 631, 703, 754, 802, 841, 869, 900, 936, 937, 968, 1073, 1084, 1113, 1144, 1150, 1172, 1184, 1196, 1225, 1263, 1273].

• Study Design Heterogeneity — The diverse range of study designs, from cross-sectional to cohort and RCTs, limits the ability to draw consistent causal inferences across all findings.
• Self-Reported Data Reliance — Many studies rely on self-reported smoking and vaping behaviors, which are prone to recall bias and social desirability, potentially affecting accuracy.
• Lack of Long-Term Follow-up — A significant portion of studies, particularly on health impacts, lack sufficient long-term follow-up to definitively assess chronic health consequences of vaping.
• Confounding Factors — Many observational studies struggle to fully account for confounding variables, such as co-use of other substances or underlying mental health conditions, making it difficult to isolate the independent effects of vaping or smoking.
• Limited Direct Comparisons — While the query is "vaping vs smoking," many studies compare either product to non-use, or examine prevalence, rather than directly contrasting health outcomes or cessation efficacy between the two.

• Standardized Outcome Measures — Develop and implement standardized measures for health outcomes, cessation, and dependence across studies to enable more robust meta-analyses.
• Longitudinal Cohort Studies — Conduct large-scale, long-term longitudinal cohort studies comparing exclusive vapers, exclusive smokers, dual users, and non-users on comprehensive health endpoints.
• Randomized Controlled Trials — Design and execute more RCTs comparing different vaping products and cessation strategies against established smoking cessation methods and placebo.
• Toxicant Biomarker Research — Expand research on biomarkers of exposure and harm for both vaping and smoking, including novel compounds, to provide objective measures of risk.
• Intervention Effectiveness Studies — Evaluate the effectiveness of targeted interventions for youth vaping cessation, dual use reduction, and addressing mental health comorbidities in nicotine users.