September 2009, Vol. 14, No. 2
ISSN 1540 5273
Sarah L. Ash, Ph.D.
This piece began to take shape as a result of two recent experiences: reading Michael Pollan’s book In Defense of Food and listening to speakers at a national conference of nutrition professionals. In both cases, I came away concerned that some of the advice being given was really not very helpful, and maybe even was contributing to the problem. I will outline some of those concerns here, presented in the context of how dietary advice has changed over the years and the challenges associated with getting that advice “right.”
While there are some aspects of dietary recommendations that remain constant (will we ever NOT encourage people to eat their vegetables?) others have been more changeable. In the first few decades of “organized” nutrition advice—the early 20th century-- starch was generally seen as the less desirable macronutrient. Among other reasons, it was associated with obesity primarily because poor immigrants ate a lot of it (potatoes, rice, pasta) and immigrant women in particular tended to be heavier (probably more the result of multiple pregnancies and the absence of a social norm valuing thinness as a reflection of self-restraint). Protein was highly valued since its unique functions were not able to be replaced by carbohydrates or fat, which were seen simply as sources of fuel.
The post WWII increase in life expectancy brought us increasing rates of deaths from heart disease (you have to live long enough to develop it in order to die from it) and the associated push against dietary fat—especially the saturated fat that was tagging along with all that high protein meat people were eating. We told folks that it wasn’t necessary to count calories, just count fat grams and all would be well. That gave us the fat-free mania of the 1980s and 90s when women joined Snackwells© buying clubs to get around the one-per-customer rules adopted to control their buying frenzies, along with an unhealthy fear of what is in fact a necessary nutrient (I had a student one semester who, upon seeing on her diet analysis printout that fresh broccoli had a few tenths of a gram of fat cried, “Broccoli has fat? Is there NOTHING I can eat?”). Of course the 90s turned out to be the era of skyrocketing obesity rates helped along by the consumption of all those fat-free cookies, which provided fuel for the decade-long Atkins low-carb phenomenon.
Now we have refined our fat message to focus on trans fat, the ironic byproduct of a desire to replace the saturated fat in butter, lard and beef tallow with something better for us. We are encouraged to tell our clients not to always believe the “0” grams listing on the label since manufacturers can “round down.” But how can they know which one is really 0? Add it to the list of things to worry about in the grocery store.
In fact this whole concept of making people fear food remains pretty firmly entrenched in a lot of recommendations. Pollan and others have picked up the “if you can’t pronounce its ingredients don’t eat it” mantra. While one could certainly argue that long lists of food additives tend to track with highly processed, and therefore less nutrient dense items, the underlying message is also that mono and diglycerides are scary-sounding “chemicals” whose unfamiliarity should be interpreted as a sign of danger. But what if broccoli had to carry a “label”--what would people think if they saw sulforaphane and indole-3-carbinol on its ingredient list? Should they be afraid because they cannot pronounce them? Meaningless justifications for making dietary recommendations are not helpful, especially when they use fear as their motivator.
But what really amazes me is that refined white sugar, once the supreme most evil-doer of all food substances (dating back at least to food reformers like Sylvester Graham in the mid 1800s) is now somehow the “natural” alternative to high fructose corn syrup (it sometimes shows up on labels as “cane sugar” to make it sound even better). I used to spend an entire class period on all of the supposed ills that have been linked to sugar over the years. Now I have to spend time setting the record straight on what we really know, and don’t know, about HFCS.
So why the ever- changing and fear-inducing advice? If you look to science to answer the question, What should I eat to stay healthy (which we do), then you are very likely to end up with a very reductive approach to food consumption. That is, scientists tend to focus on one thing at a time, constantly refining their understanding of it (hence the transition from total fat to saturated fat to trans fat, and now the distinctions between fatty acids of the omega 3 and omega 6 persuasion). Part of the problem with the research on high fructose corn syrup is that much of it actually just looks at fructose by itself, even though HFCS is actually about 45% glucose.
But while it is certainly important to continue to advance our knowledge of individual nutrients and their effects in the body, applying each new piece of information to dietary advice tends to make that advice much more complicated, and therefore less practical. It also contributes to the good food/bad food dichotomy that generates uncertainty and fear. The reality is that food, disease, and people are all incredibly complex; trying to find the ONE answer in a type of fat or sugar seems unwise.
A friend who had experience in the nutrition-writing business once told me that to get published you needed something new and “sexy.” Unfortunately the best dietary advice is likely also the most boring: Eat less; Exercise more; All things in moderation; Variety in all things, especially fruit and veggies (much of which, of course, is represented in MyPyramid.gov).
People don’t need to obsess about the scary-sounding ingredients in the cracker box if they don’t eat the whole box in one sitting; they don’t need to worry about the 0.4 grams of trans fat per teaspoon in the margarine if they don’t put a huge cube of it on their potato (and they shouldn’t put a huge cube of it on their potato regardless of the type of margarine they’re using). In fact not worrying about food and enjoying it (in moderation) might make folks healthier too.
Obviously this is nothing new; it is, as my father used to say, what his saintly grandmother could have told you. Unfortunately that doesn’t sell books or make headlines. But there is likely more truth in it than just about any health book out there.
Sarah L. Ash, Ph.D. is and Associate Professor and Nutrition Undergraduate Cordinator for nutrition Science in the Departemnt of Food, Bioprocessin and Nutrition Science at NC State University. For more information you can contact her at 919-515-4043, or at firstname.lastname@example.org.