{"id":32665,"date":"2025-12-22T21:36:15","date_gmt":"2025-12-22T21:36:15","guid":{"rendered":"https:\/\/clearingtheair.eu\/?p=32665"},"modified":"2025-12-22T21:36:20","modified_gmt":"2025-12-22T21:36:20","slug":"scary-headlines-shaky-science-why-some-vaping-studies-dont-add-up","status":"publish","type":"post","link":"https:\/\/clearingtheair.eu\/en\/post\/scary-headlines-shaky-science-why-some-vaping-studies-dont-add-up\/","title":{"rendered":"Scary headlines, shaky science: why some vaping studies don\u2019t add up"},"content":{"rendered":"\n<ul class=\"wp-block-list\">\n<li><strong>Some recent studies linking vaping to heart disease and cancer rely on weak or inconsistent methods.<\/strong><\/li>\n\n\n\n<li><strong>Experts say \u201cadjusting for smoking\u201d is often done too crudely to separate vaping risks from decades of past smoking.<\/strong><\/li>\n\n\n\n<li><strong>Reviews that combine flawed studies can give a false sense of scientific certainty.<\/strong><\/li>\n\n\n\n<li><strong>Poorly designed studies can mislead the public by treating vaping as if it carries the same risks as long-term smoking.<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Headlines about vaping and serious disease can be frightening. Heart attacks. Strokes. Cancer. When studies appear in respected journals making these links, it\u2019s easy to assume the science is settled.<\/p>\n\n\n\n<p>But many experts say it isn\u2019t &#8211; and that some widely cited studies should be treated with caution, not because vaping is risk-free, but because the research methods behind the claims are shaky.<\/p>\n\n\n\n<p>Two recent cases help explain why.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>The smoking history problem<\/strong><\/h3>\n\n\n\n<p>One high-profile <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/41381772\/\" rel=\"nofollow noopener\" target=\"_blank\">review<\/a> claims that people who use vapes have a higher risk of heart attacks and strokes. To address the obvious issue &#8211; that most people who vape used to smoke &#8211; the authors say they \u201cadjusted for smoking.\u201d<\/p>\n\n\n\n<p>That sounds reassuring. In reality, critics say it often means little more than sorting people into broad boxes: never smoked, former smoker, or current smoker.<\/p>\n\n\n\n<p>Harm reduction expert Clive Bates says that approach should \u201cring immediate alarm bells.\u201d<\/p>\n\n\n\n<p>\u201cHow would we even know the answer to the question?\u201d he asked. \u201cIt is not simply a matter of \u2018adjusting for smoking\u2019 as if that is a practical thing to do.\u201d<\/p>\n\n\n\n<p>Heart disease doesn\u2019t work in neat categories. Risk builds up slowly over decades. Someone who smoked for 30 or 40 years, then spent a short time dual-using cigarettes and vapes before switching entirely, carries that long-term damage with them.<\/p>\n\n\n\n<p>\u201cThe effects of these exposures are cumulative and progressive,\u201d Bates said. \u201cHow would you adjust for 35 years of smoking, followed by three years of dual use, then two years of exclusive vaping? That total history is the actual exposure.\u201d<\/p>\n\n\n\n<p>Labeling someone simply as a \u201cformer smoker\u201d doesn\u2019t erase decades of harm. But many studies don\u2019t even record basic details such as years smoked, when someone quit, or how long they\u2019ve been vaping.<\/p>\n\n\n\n<p>Bates said: \u201cGenerally, the \u2018adjustment\u2019 is just for never, former, or current smoker status. That doesn\u2019t capture cumulative lifetime exposure.\u201d<\/p>\n\n\n\n<p>As a result, harms caused by years of smoking can end up being blamed on vaping, especially when vaping is relatively recent. Notably, in these studies, the strongest signals of harm tend to show up among former smokers, not among people who never smoked at all. To many experts, that\u2019s a red flag.<\/p>\n\n\n\n<p>As one reviewer noted, the only significant associations appeared among former smokers, not among never-smokers. This suggests the findings may reflect lingering effects of past smoking or other confounding factors rather than vaping itself.<\/p>\n\n\n\n<p><strong>Cause and effect can get flipped<\/strong><\/p>\n\n\n\n<p>There\u2019s another issue that\u2019s easy to miss. Many of the studies used in these reviews look at people at a single point in time. That makes it hard to know what came first.<\/p>\n\n\n\n<p>Did vaping lead to poor health? Or did people who already felt unwell, after years of smoking, switch to vaping in hopes of reducing harm?<\/p>\n\n\n\n<p>\u201cReverse causation can never be ruled out,\u201d Bates said. \u201cPeople beginning to feel ill as a result of smoking may take up vaping to mitigate their risk. How is that handled?\u201d<\/p>\n\n\n\n<p>In short, it often isn\u2019t. This problem can\u2019t be solved with statistics alone. You need long-term studies that follow people over many years, tracking smoking histories, switching patterns, and health outcomes over time. Those studies don\u2019t yet exist for vaping.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>When reviews magnify weak evidence<\/strong><\/h3>\n\n\n\n<p>Systematic reviews and meta-analyses are often described as the strongest kind of evidence. But they\u2019re only as good as the studies they include.<\/p>\n\n\n\n<p>If most of those studies share the same weaknesses &#8211; poor measurement of smoking history, short follow-up, unclear timing &#8211; then combining them doesn\u2019t fix the problem. It can actually make the results look more definitive than they really are.<\/p>\n\n\n\n<p>\u201cSystematic review and meta-analysis is often code for ignoring the flaws that are common to all the studies included,\u201d Bates warned.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>A cancer review under fire<\/strong><\/h3>\n\n\n\n<p>Concerns become even stronger in the case of a recent <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/40691942\/\" rel=\"nofollow noopener\" target=\"_blank\">review linking vaping to cancer<\/a>, which prompted a detailed letter to the editor from independent researchers.<\/p>\n\n\n\n<p>The authors say they identified \u201cundisclosed protocol deviations, inconsistencies between the reported search strategy and the included evidence, misclassification of study designs, internal contradictions, numerical discrepancies, and unsupported conclusions.\u201d<\/p>\n\n\n\n<p>Among the problems they cite are changing the study rules midstream without disclosure, adding study types that were originally excluded, and mixing cancer incidence with biomarkers that do not measure cancer at all.<\/p>\n\n\n\n<p>\u201cAdmitting biomarker or inflammatory marker studies under the category of cancer incidence creates a disconnect between the stated objective and the evidence included,\u201d the letter says.<\/p>\n\n\n\n<p>Even more troubling &#8211; a study that had already been retracted appeared in the review, and was still rated as high quality. Basic numbers didn\u2019t add up either, including cancer case counts that exceeded the total number of participants.<\/p>\n\n\n\n<p>\u201cThese are not minor oversights,\u201d the authors wrote. \u201cThey undermine the transparency, accuracy, and interpretability of the review.\u201d Taken together, they argue, the evidence base is far too inconsistent to support claims that vaping increases cancer risk.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>What all this means<\/strong><\/h3>\n\n\n\n<p>None of this means vaping is completely harmless. Nicotine is addictive, and inhaling chemicals isn\u2019t risk-free. But it does mean that claims about vaping causing heart attacks or cancer should be based on solid, transparent science, especially when they\u2019re used to shape public policy or alarm consumers.<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Headlines about vaping and serious disease can be frightening. Heart attacks. Strokes. Cancer. When studies appear in respected journals making these links, it\u2019s easy to assume the science is settled. But many experts say it isn\u2019t &#8211; and that some widely cited&hellip;<\/p>\n","protected":false},"author":990002,"featured_media":32666,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[257,259],"tags":[186],"slider":[],"class_list":["post-32665","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","category-science","tag-nicotine"],"_links":{"self":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/32665","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/users\/990002"}],"replies":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/comments?post=32665"}],"version-history":[{"count":1,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/32665\/revisions"}],"predecessor-version":[{"id":32673,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/32665\/revisions\/32673"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/media\/32666"}],"wp:attachment":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/media?parent=32665"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/categories?post=32665"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/tags?post=32665"},{"taxonomy":"slider","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/slider?post=32665"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}