Fatal flaws
Earlier this month, I told you about another study implicating essential nutrients for increasing the risk of lung cancer in smokers. In that eTip (4/9/09, subject line "Weighing your options"), I pointed out that the study's findings hardly seemed rational, considering the increased risk was found only in smokers -- whose habit already puts them at a significant disadvantage. And, apparently, I'm not the only one who thinks the conclusions drawn by this study's research team are more than a little skewed. Just the other day, I came across an article arguing the very same point. According to Professor Hans Konrad Biesalski from the Institute for Biological Chemistry and Nutrition at the University of Hohnheim in Germany, the study casting doubt on beta-carotene and other carotenoids "was based on invalid methodology, questionable statistical evaluations, and speculative explanations." One of the major questions Professor Biesalski raised involved the accuracy of the data examined by the researchers. Much of the information was gathered from questionnaires filled out by the study participants. Biesalski argues that relying on memory is a flawed approach, particularly when they subjects were asked about their dietary and supplement habits as far back as 10 years ago. In addition to Professor Biesalski's criticisms of the study, the article I read also included some insightful commentary from another source, Andrew Shao, PhD, the vice president of scientific and regulatory affairs at the Council for Responsible Nutrition. According to Sha "This study simply adds to the fast evidence base already showing that smoking causes lung cancer. The conclusion is simple and has nothing to do with supplements: smoking increases the risk of lung cancer." Shao also gave what may be the soundest advice to date about how to proceed amidst this ongoing controversy: "Dietary supplements are not meant to be used as magic bullets to undo a lifestyle of unhealthy habits, such as smoking -- rather they are meant to be used as part of a healthy lifestyle, such as eating a healthy diet, exercising, and not smoking in the first place." I couldn't have said it better myself. | 
