Don't blame the media, but the news you're reading regarding the impact of food on chronic disease is almost certainly wrong.
So will a low-carb diet filled with egg yolks, red meat, dark chocolate, and devoid of white rice leave you skinny and diabetes free, but with hardened arteries or worse?
Maybe. The thing is, we just don't know, and neither do any of the studies those headlines were built from. They don't know for two reasons. The first plagues all nutrition research—it's virtually impossible to craft a study that will conclusively champion or vilify a single food. It's impossible because ethically we cannot create an experimental condition in which we randomly assign thousands of people to consume very specific diets differing in only one food, and then have them consume those identical-but-for-one-food diets for decades, to evaluate the impact of that food. Instead, what we try to do is take massive cohorts of people, then use statistical wizardry to account for dozens of potentially confounding variables (such as exercise, other presumed dietary contributors to risk, smoking, age, co-existing medical conditions, socio-economic status, education), and then draw conclusions. While these types of studies can sometimes be helpful, more often than not, they overlook other variables that may be just as, and sometimes even more, likely to have led to the reported outcomes.
Take for example the recent egg-scare study. First, did you know that the authors didn't control for many known contributors to heart disease, including what else the study subjects were eating (such as trans-fats), their waist circumferences, or how much they did or did not exercise? That's problematic, since the study was trying to suss out the impact of egg consumption on the hardening of arteries—which can raise one's risk for heart attack. Second, did you know that the way in which the researchers determined the number of eggs people were eating was by simply asking participants how many eggs they ate per week and for how many years? Could you answer that question accurately?
So why weren't these methodological shortcomings uniformly reported on by the media? Why didn't the media recognize this study as being not much better than useless, given its glaring flaws? Perhaps because they got their information and contacts from institutional press releases, which attempt to increase university publicity by highlighting their researchers' findings. In this case, the University of Western Ontario headlined their press release, "Research Finds Egg Yolks Almost as Bad as Smoking," and stated that "eating egg yolks accelerates atherosclerosis in a manner similar to smoking cigarettes." Yet they didn't include a single word of caution into the interpretation of the study's results until the final paragraph, where one of the authors says that more research is needed to ensure the results weren't actually due to differences in exercise or waist circumference; regardless, they wrote that, according to the study's lead author, "regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease."
Yes, the media can and should do their own fact digging and study reading, but let's face it: While some university press teams may overstate study findings inadvertently, others probably realize that not every reporter has the statistical know-how to interpret study methodologies, that reporters are increasingly pressed for time, and that given the release is coming directly from a university, reporters may not question whether headlines have been overhyped. Either way, the misinformation creates confusion in an already confusing nutrition climate.
To their credit, some news organizations and reporters do a stellar job at accurate science reporting. But if you're looking for a simple rule to follow, I'd recommend you ignore any article that suggests a single food confers either miraculous or devastating health effects. And if you're really worried about healthy living, just go back to basics. Cook from fresh, whole, real ingredients; minimize your meals out; eat around a table with your family; exercise for 20 minutes or more, most days of the week; and then go to sleep knowing you've done more for your health than what avoiding or including any one specific food could ever do.
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Yoni Freedhoff, MD, is an assistant professor of family medicine at the University of Ottawa, where he's the founder and medical director of the Bariatric Medical Institute—dedicated to non-surgical weight management since 2004. Dr. Freedhoff sounds off daily on his award-winning blog, Weighty Matters, and is also easily reachable on Twitter. Dr. Freedhoff's latest book Why Diets Fail and How to Make Yours Work will be published by Simon & Schuster's Free Press in April 2013.