For decades, health professionals have been advising the public to eat less “bad fat” (saturated and trans fats) and more “good fat” (unsaturated fats), but should the message be that simple? More importantly, do we have the right fats in each category? The science is clear about the negative impacts of trans fats but arguably less so when it comes to saturated and unsaturated fats.
The results of recent study published in the journal Annals of Internal Medicine caused quite the media frenzy when it revealed that there is no connection between saturated fat intake and heart disease; that in fact, there may actually be some harm to consuming too little saturated fat. These results had foodies like Mark Bittman exclaiming, “butter is back!” in his New York Times article, and reputable news sources such as NPR hosting a show devoted to discussing the study.
When I was listening, I was struck by one question that the show’s host, Tom Ashbrook, kept asking his expert guests: “So, does this mean we should eat more butter and fatty meats?” None of the guests would answer his question directly (because the answer is not a simple yes or no), and by the end of the show, you could hear the frustration in Tom’s voice as he tried to wrap up with the answer to his question left unclear.
To further complicate matters, there is increasing evidence that some unsaturated fats (aka the “good fats”) are detrimental to our health. To understand this better, it is important to know that there are two types of unsaturated fats: monounsaturated and polyunsaturated. Polyunsaturated fats can be furthered categorized into two types: omega-3 polyunsaturated fats and omega-6 polyunsaturated fats. Here are examples of food sources of each:
|Monounsaturated Fat Sources||Omega-6 Polyunsaturated Fat Sources||Omega-3 Polyunsaturated Fat Sources|
High oleic safflower oil
Fish: trout, herring, and salmon
The issue is two-fold: first, omega-6s and omega-3s are ideally consumed at a ratio of 2-3:1, but in western diets, they are typically consumed at a ratio of 15:1, because in general, our diets are rich in omega-6 fatty acids and sparse in omega-3 fatty acids. This promotes the pathogenesis of many diseases including cardiovascular disease. The second area of concern is the instability of polyunsaturated fats. Polyunsaturated fats oxidize very easily when exposed to air, light, and heat, and oxidized fats wreak havoc on the body. Soybean, corn, and safflower oil are some of the most prevalent oils in our food supply, and because they are often used in high-heat cooking, we are also getting them in their most dangerous form: oxidized.
So where we are today is a place where I would say we have always been. Where nutrients do not fit neatly into “good” and “bad” categories and the quality and preparation method of the food in which they are found is critical. The good news is that butter can be part of a healthy diet—and that’s an easy message to communicate. The more difficult part of our job is in overcoming media messages that label individual nutrients as good or bad, and instead educate the public about the importance of quality and balance.
Ayla Withee is a Boston-based registered dietitian nutritionist with a Masters of Science in Health Communication from Boston University. She is owner and chief nutritionist for Boston Functional Nutrition, LLC, an integrative and functional nutrition therapy practice based in Natick, MA. In addition to providing nutrition counseling for individuals, Ayla also consults for a fortune 500 company, providing corporate wellness program management. She has written and lectured widely on various nutrition topics including food allergies and sensitivities, fertility, detoxification, organic and GMO foods. You can find her blogging about all things nutrition at Boston Functional Nutrition.