References Matter

When one is diagnosed with cancer, all sorts of well-intentioned but incorrect advice comes one’s way. I can speak to this personally. After being diagnosed with my cancer, it was recommended that I go on a cottage cheese & apple cider vinegar diet. I reasonably asked what this recommendation was based on, and was told that a doctor on the internet swore by this. An exchange from the movie “Sleepless in Seattle” came to mind:

Jonah: “Trust her dad, she’s a doctor.”

Sam: “Her first name could be doctor!”

After a medical diagnosis, one thing you should NOT do is to peruse the internet, where one can find all sorts of similarly well-intentioned-but-misguided advice, ranging from the probably-not-helpful-but-at-least-not-harmful aforementioned apple cider vinegar and cottage cheese diet, to things that could result in outright harm.

If I had to cite one thing that was the most critical factor in my career swerve from dermatology into lifestyle medicine, it would be the book “How Not to Die” by Dr. Michael Greger. In it, every factoid is explicitly referenced, and the book appears large only because it contains citations for every assertion.1 Until I read that book, I had not realized that there was an entire evidence-based specialty addressing the factors that contributed to health, one which did not involve crystals or other non-evidence-based snake oils. I am aware that the editors of journals are not immune from influence (as the last three years have so painfully demonstrated, with major and previously-respectable journals publishing blatantly fraudulent “studies”)2,3 however they are generally better than completely unreferenced opinions. Unfortunately, a former editor-in-chief of one of these illustrious tomes laid out the true situation (all the way back in 2008), lamenting that “Physicians can no longer rely on the medical literature for valid and reliable information.”4 Robert F. Kennedy, Jr. appropriately refers to the purveyors of “bought science” as “biostitutes.”

Previous to the COVID public health debacle, if the pharmaceutical industry sponsored a study, it was four times more likely to show benefit/no harm5 than not, the telecommunication industry was 10 times more likely to report no harm from cell phones,6 and the tobacco industry was 100 times more likely to report no harm from cigarettes.7 I suspect that the pharmaceutical industry number in particular has drastically increased. Sometimes the evidence can be dramatically varied, and this may be intentional as well. Whenever there is an extreme variation in data (think of hydroxychloroquine being “demonstrated” to be dangerous, while many countries deem it to be so safe that it is available to all without a prescription), one should always suspect that some type of bias is involved. In a memo to another tobacco industry marketing executive, one marketer states that “Our product is doubt…”8 Not cigarettes. Doubt. Unfortunately, science can be (and often is) bought, so one has to scrutinize studies more than ever before, but still, references can be the difference between opinion and fact, and are often the best information we have to go on. No one reference or study is ever enough to change practice behavior, but they can be a helpful addition to the body of evidence.

So yes, even with much misbehavior at play in medicine and science these days, references still matter.


  1. Greger, Michael, and Gene Stone. How Not To Die. Macmillan, 2016.
  2. Funck-Brentano C, Nguyen LS, Salem JE. Retraction and republication: cardiac toxicity of hydroxychloroquine in COVID-19 [retraction of: Lancet. 2020 May 22;:]. Lancet. 2020;396(10245):e2-e3.
  3. Mehra MR, Desai SS, Kuy S, Henry TD, Patel AN. Retraction: Cardiovascular Disease, Drug Therapy, and Mortality in Covid-19. N Engl J Med [retraction of: N Engl J Med. 2020 Jun 18;382(25):e102]. N Engl J Med. 2020;382(26):2582.
  4. Marcia Angell. Industry-Sponsored Clinical Research – A Broken System. JAMA 2008;300(9):1069-1071.
  5. Huss A, Egger M, Hug K, Huwiler-Müntener K, Röösli M. Source of funding and results of studies of health effects of mobile phone use: systematic review of experimental studies. Environ Health Perspect. 2007;115(1):1-4.
  6. Ibid.
  7. Barnes DE, Bero LA. Why review articles on the health effects of passive smoking reach different conclusions. JAMA. 1998;279(19):1566-1570.
  8. Executive at Brown & Williamson owned by R. J. Reynolds Tobacco Company, 1969 (from Doubt Is Their Product by David Michaels, also quoted in Scientific American, June 15, 2005).