Posts Tagged ‘dietary supplements’

Understanding the Science of Elusive Health Risks

January 6, 2017

The title of this post is the subtitle of “Getting Risks Right” a book by an American epidemiologist and cancer researcher Geoffrey C. Kabat. He is a senior epidemiologist at the Albert Einstein College of Medicine.  Understanding these health risks is an extremely difficult task and Kabat makes a strong effort to assist us in executing this task.

The Preface asks the question “Why do things that are unlikely to harm us get the most attention?’  The simple answer is that science takes time and moves slowly, but people want quick answers.  The popular press publishes apparent answers that are a long way from being validated.

The first chapter is titled, “The Illusion of Validity and the Power of ‘Negative Thinking,’ and begins with the following quote from Francis Bacon:  “It is the peculiar and perpetual error of human understanding to be more moved and excited by affirmatives.
The root of all superstitions is that men observe when things hit but not when they miss; and commit to memory the one and forget to pass over the other.”

Chapter 2 describes the fundamentals of studies in the area of public health.  Ioannidis’s landmark article “Why Most Published Research Findings are False” (PLOS Medicine, 2, 3124. Doi:101371/journal pmed, 0020124, 2005) has been cited in several previous healthy memory posts.  The consensus among epidemiologists and statisticians is one of general agreement.  But most people remain ignorant of the situation.  The only article in the popular press of which HM is aware is Why Most Published Research Findings are False” (PLOS Medicine, 2, 3124. Doi:101371/journal pmed, 0020124, 2005).  Kabat discusses additional scientific difficulties in conducting scientific research in the area of health.  Please read his book to understand the relevant issues.

However, health research has additional difficulties because here the science is embedded in a society that is highly attuned to the latest potential or breakthrough.   Kabat writes, “Findings from rudimentary studies often are reported as if they were likely to be true when, in fact, most research findings are false or exaggerated, and the more dramatic the result, the less likely it is to be true.”  Later he writes, “Reports of exaggerated findings can, in turn, give rise to ‘information cascades’—highly publicized campaigns that can sow needless alarm and lead to misguided regulation ad policies.  These difficulties are thoroughly aired in Chapter 3.

The final four chapters of the book discuss 4 areas of research.  Chapter 4 explores the question of whether exposure to radio frequency energy causes brain cancer.  The issue, whether the worldwide adoption of a novel technology within a short time span could be causing a fatal disease.  Kabat documents the extensive research carried out over two decades provides no strong or consistent evidence to support this possibility.

Chapter 5 explores the main lines of preoccupation with “endocrine disrupting chemicals” in the environment hypothesis.  Although this certainly was a legitimate concern, Kabat documents how false ideas based on poor data got enormous attention.  He explains how to make sense of a bitter controversy that is currently raging in the scientific and regulatory communities in Europe and the United States.

Chapter 6 describes a little-known success story.  By linking a long-standing enigmatic disease in the Balkans to dietary exposure to a toxic herb that has been used in traditional cultures throughout history.  Research on aristolochic acid contained in certain varieties of the herb Aristolochia has  led to new insights on the carcinogenic process as well as highlighting the threat posed by the woefully inadequate regulation of thousands of products marketed as “dietary supplements.”  More than half of Americans use these products to the tune of $32 billion a year.  Unfortunately, naive consumers
wrongly believe that the government requires manufacturers to report all adverse effects and that the FDA must approve supplements before they are sold.  Few consumers of supplements are aware of the implications of the Dietary Supplements and Health Education Act (DSHEA), passed by Congress is 1994 with strong support from the supplements  industry and its political allies.  By defining herbal supplements and botanicals as “dietary supplements,” DSHEA excluded them from the more rigorous standards used in regulating prescriptions and even over-the-counter drugs.  By not making herbal supplements and botanicals subject to testing, US citizens are being put at risk.  This point is underscored by the following quote from Simon Singh and Edzard Ernst :  “Just because something is natural does not mean that it is good, and just because something is unnatural does not mean that it is bad.  Arsenic, cobra poison, nuclear radiation, earthquakes, and the Ebola virus can all be found in nature, whereas vaccines, spectacles, and artificial hips are all man-made.”  In this context HM would like to comment on the labeling of Genetic Modified Organisms (GMOs) as being bad.  To the contrary, they might be the only option for feeding an increasingly growing population.  The also offer the prospect of both better tasting and affordable products.

Chapter 7 recounts another success story, the long-standing question of what causes cervical cancer led, over a period of thirty years, to the identification of a small number of highly specific carcinogenic subtypes of the humanpapillomavirus (HPV).  The persistent infection with one or more of these subtypes is necessary to cause the disease.  This knowledge has led to the development of vaccines that have the potential to virtually eliminate cervical cancer as well as to fundamental new knowledge about how the virus evolved to cause cancer.

Kabat comes to the following conclusion, “the need for a more nuanced and realistic view of science, which acknowledges the enormous challenges, promotes skepticism toward widely circulated but questionable ides, and at the same time pays attention to what science can achieve at its best.

At this point please indulge HM in a personal story.  When he was working, he received a call from a representative of his insurance company.  This representative encouraged an annual checkup to include the prostate specific antigen test (PSAT).  For decades this had been a standard recommendation to men of my age.  However, HM tries to keep up with the literature.  He had read that urologists, the individuals most knowledgeable about the benefits of this test, had changed this long-standing recommendation.  Now the test is recommended only in certain high risk patients, and then, only after consulting with a physician.  However, it took another year before the rest of the medical community followed the lead of the urologists.

© Douglas Griffith and healthymemory.wordpress.com, 2016. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Advertisements