Butter is like a forlorn and forsaken ex you’d rather not remember because you know you won’t be able to turn her—sorry, it away again. The temptation is just too much. But, if you’ve been using vegetable oil substitutes in an effort to ward off heart disease, you might be doing yourself a disservice, according to a meta-analysis from the University of North Carolina Health Care.
Your seemingly heart-healthy decision to swap butter for safflower, soybean, sunflower, and corn oil probably stemmed from the fact these oils are high in linoleic acid, a polyunsaturated omega-6 fatty acid said to help increase metabolism, boost your immune system, and keep cholesterol levels in check.
And linoleic acid has been found to have these benefits in the body. But the potential to save your heart? Eh, maybe not so much.
Researchers recovered a huge controlled trial—dating between 1968 and 1973—conducted by the University of Minnesota, which tested whether linoleic acid-based dietary interventions could reduce the risk of heart attacks or deaths on 9,423 men and women. The investigators found men and women who switched to corn oil from butter and other saturated fats did lower their cholesterol levels, but there were no marked changes in their risk for heart attacks, deaths from heart attacks, or overall death.
Current North Carolina researchers also performed their own analysis and verified the cholesterol-lowering effect of the dietary intervention from butter to linoleic acid. But they also exposed some unsettling findings: Based on recovered autopsy records, the corn oil group from that 1968-1973 trial had almost twice the number of heart attacks as the control group. Further, women and patients older than 65 suffered about 15 percent more deaths during the trial compared to their control counterparts. What's more, when Zamora and her team recovered more unpublished data from another trial (this time from the Sydney Diet Heart Study circa 2013), they found the same thing: more instances of heart disease and death among linoleic acid intervention participants.
The North Carolina researchers added their combined data (from four randomized clinical trials) and concluded there’s no evidence linoleic acid-rich oils can protect your heart or life—or that's it's any better than butter in that regard.
That’s not to say replacing saturated fat (butter) with corn oil or safflower oil is a recipe for disaster, study author Daisy Zamora, Ph.D., says since their analyses were based on partial recovery from patient data and research files. The takeaway is more that making the swap may not be as "healthy" as you think.
Plus, *certain kinds* of butter, namely the grass-fed kind, have been earning a better nutrition rep as of late.
The nutrition properties of butter improve with how much grass is in a cow’s diet, according to materials from the Journal of Dairy Science. Grass-fed butter has less saturated fat and more unsaturated (good) fatty acids, which can be stored within your muscle cells as intramuscular triglycerides, adding to that pumped-up look when you train. They can also act as a fuel source during exercise.
Worry less about saturated fat from healthy, whole foods like grass-fed beef, coconuts and coconut oil, eggs and, yes, butter, and worry more about your sugar and overall calorie intake. Oh, and if you think "organic" or "grass-fed" food products are just a marketing ploy, know that fat is where toxins are stored; so, healthy animals mean better, healthier byproducts.