In March, New York Times writer and famous foodie Mark Bittman declared that “butter is back.” His piece reported on the findings of a recent meta-analysis published in the Annals of Internal Medicine that questioned the long-standing link between saturated fat and coronary disease.
While Bittman celebrated the findings and told readers they could “go back to eating butter,” nutrition and public health professionals have been quick to caution, “Not so fast!”
Dr. David Katz, Director of the Yale Prevention and Research Center, responded to the piece, pointing out Bittman’s lack of qualifications for interpreting scientific studies and ultimately calling the writer “a potential danger to the public health.”
The Harvard School of Public Health put out a statement in the wake of the meta-analysis’ publication calling its conclusions “seriously misleading,” highlighting “many errors and omissions.”
So, who are we supposed to trust? And why does nutrition news often seem completely contradictory? For anyone wanting to make simple choices towards leading a healthier life, this sort of back-and-forth is confusing at best and infuriating at worst.
Here are five takeaways from headline-grabbing nutrition news and the recent debate on saturated fat.
1. Butter is not back, but it sure makes a good headline.
And catchy headlines don’t tell the whole story. Unfortunately, what often happens in our media is that the findings of a complex study get whittled down into sound bites, often leading to glib and misleading statements like, “butter is back.” Amid this cycle, the weight of the body of scientific evidence is neglected in favor of a catchy headline.
2. The study was flawed.
When pooling the results of previous observational studies together, the authors of the meta-analysis did not find a significant difference in rates of heart disease between those who consumed lower amounts of saturated fat and those who consumed higher amounts. This seemed surprising.
However, the meta-analysis itself has come under intense scrutiny from the scientific community, namely because it failed to specify a comparator group for saturated fat. When people consume less saturated fat, they fill the gap with something else. Unfortunately, most often that "something else" is processed food high in sugar — food that also does little for our health. If the overall quality of the diet is unchanged — if a "bad" food is simply replaced by another "bad" food, then we will likely not see a positive health effect of the dietary change.
In other words, as Dr. Katz put it, “Saturated fat ... may not be bad for hearts and health compared to other things that are bad for hearts and health. But there is no evidence they are good for hearts and health...[This study] merely shows that there is more than one way to eat badly." (For Katz’s detailed pick-apart of the study, read here.)
3. Not all fats are equal.
In the low-fat craze of the last few decades, an important message has gotten lost — that not all fats are “bad.” However, in the more recent “fat-is-back” trend, we’ve also lost sight of the idea that not all fats are created equal. Generally, nutrition research finds that trans and saturated fats (such as those found in fried foods, red meat and full-fat dairy) do us few favors, while mono- and polyunsaturated fats (such as those found in nuts, vegetable oils and avocados) are correlated with beneficial health outcomes. Pick fats that pack a healthful punch.
4. The status quo is SAD.
The Standard American Diet (SAD) is already full with excess calories, processed foods, added sugars and unhealthy fats. In spite of the recent barrage of media coverage, the findings of this meta-analysis do not grant permission to add foods high in saturated fats to an already SAD status quo.
5. A healthy, whole-foods diet matters more than specific nutrients.
Despite the confusing and seemingly contradictory “news” about nutrition, the body of scientific evidence is consistently clear. Diets high in fruits, vegetables, whole grains, and nuts, and low in saturated and trans fats and added sugars are associated with a lower risk of coronary and other chronic diseases.
We're all drawn in by news of a quick fix or a single “good” or “bad” nutrient. But the simple truth remains that active lifestyles and dietary patterns built on whole foods make a sustainable difference in our long-term health. I’d say that’s some pretty good news.