I was recently asked to compare butter and margarine and provide my professional recommendations. And by recently, I mean every single day in which I interact with patients. Despite this, I haven’t actually done a lot of reading up on the topic lately as heart health is not presently the primary component of my work. I have my immediate gut reaction (choose margarine), but I know that this is largely informed by a) being brought up in a margarine family and b) receiving my formative nutrition education during a time when saturated fats in butter were the known bad guys, trans fats were the new boogeymen, and omega-3 fats were going to save us from all our ills. In my attempts to be as honest and transparent as possible, I thought this would be great a topic to review the newest findings and perhaps challenge my preconceived notions.
First a brief summary of these two spreads. Butter is made from cow’s milk (and occasionally goat, sheep, and yak milk, in other parts of the world). The milk, more specifically the fat-heavy cream, is churned until the fat separates into a solid mass. It may or may not have other flavourings, colour, or salt added to it. Margarine was invented in the late 19th century as a cheap and plentiful replacement for butter, available to the poor. It has gone through iterations, starting as a mixture of beef tallow and milk, into hard stick margarines and shortenings made from hydrogenated vegetable oils (soy, corn, sunflower, etc.), and finally into the various soft margarines available today. In the flavour department, butter beats margarine hands down. However, in the departments of cost and ease of use, margarine retakes its lost ground. Both foods work well in most applications, though butter is required for some delicate baked goods.
The points below are informed by and at times summarized from this fantastic article on the subject. I highly suggest reading it.
Both butter and margarine are mainly fat, with a minute amount of protein, and some vitamins (mainly A, but also D in margarine). Margarine has some additional emulsifiers to prevent the oils from separating. Nutritionally, butter is made of mostly (64%) saturated fat, margarine is typically 12% saturated fat. The remainders of both are made of some mono-unsaturated fat – the cardio-protective fats in olive oil – a lot of polyunsaturate omega-6 fats (naturally found in most plant fats) and varying amounts of omega-3 fats (another heart smart fat that plays a role in inflammation reduction and brain protection). The amount of omega-3 in butter is determined by the cow’s diet (grass-fed=more omega-3 fat), while in margarine it is determined by the types and proportions of oils used in production.
The argument for butter often comes down to two items: the taste (which is covered above) and the fact that it is natural. The arguments for margarine have long included long shelf life, low cost, low saturated fat, and more recently, higher polyunsaturated fats (both omega-6 and omega-3). If you’ve read my writing before, you’ll surely know that believing that something is superior simply because it is natural is not a logical way to make decisions. Assertions like “I trust cows more than I trust chemists” (please finish this article before clicking on that link) make it seem as though cows strive to make a delicious edible fat that tantalizes the taste buds of humans. They don’t. They make milk for their own offspring, and clever, greedy homo sapiens have figured out how to turn that into butter. I am all for whole, minimally processed foods most of the time, but I want evidence to convince me that that “natural” thing is better.
The argument against butter is built on its high saturated fat content. In the mid-twentieth century epidemiological research was emerging linking high saturated fat intake to high rates of heart disease and stroke. Since then, both the American Heart Association and the Canadian Heart and Stroke Foundation have encourage the public and policy makers to avoid saturated fats and choose polyunsaturated fats instead. And so, the great margarine migration began. Since then a lot more research has found that saturated fat is likely not as evil as once thought and that there are many other important nutritional factors in the development of heart disease. Whether or not we should include more saturated fat, in place of plant fats is currently hotly debated, but good evidence suggests that saturated fats probably shouldn’t be our only fat source.
The arguments against margarine are that it’s artificial (the naturalistic fallacy at play yet again) and that it is a significant source of trans fats. Trans fats are formed during the process of hydrogenation, where a chemical reaction adds extra hydrogen atoms to unsaturated fats. These fats are much more like saturated fats (solid, longer shelf life) but they come with the unfortunate side effects of greatly increasing the risk of heart disease, lowering our protective HDL cholesterol, and increasing inflammation. Butter also contains some trans fats, but these types do not appear to have negative health outcomes. Industrial trans fats should be avoided whenever possible. Here it is important to point out that not all margarines are created equally. Hard or stick margarines are significant sources of trans-fats (that’s what makes them hold their shape like butter). While these were common place during most of the last century, these are much less available today (if you see them, move on). Margarine manufacturers are now primarily producing soft-tub margarines, many virtually free of trans-fats, thanks to new techniques (fat interesterification) that mix different types of oils and fats to reach the desired taste and consistency. For example, Becel has 0.026g trans-fat per teaspoon whereas Imperial stick margarine has 1.5g in the same volume. Given that the guidelines suggest no more than 2 g per day, the soft margarine is quite an improvement. Today’s margarine ain’t your grandmother’s margarine, a fact conflated in articles like this one, but it does still contain a small amount of trans fat and we don’t yet know the long-term health effects (if any) of these new oil-mixing methods.
While human health choices should be highly important in our dietary choices, we should also consider the impacts of these choices on the environment. Increased butter use would increase dairy agriculture, which would increase the amount of feed grown for cattle, as well as increase the amount of manure and green house gas emissions from those cows. We should also be mindful of the cost difference of butter to margarine; encouraging only butter could effectively leave many lower-income people unable to afford the “healthier” option, strengthening the class divide. How would this help a group that is already disproportionately affected by chronic disease? Perhaps that just made your butter taste a little less good.
Which leads back to the question, butter or margarine? That question is still hard to answer because we need to take into account our overall dietary habits. Like everything else, moderation and variety are important. Try to use a variety of cooking fats including plant oils (cold-pressed when and if you can afford them) and spreads. If you only use butter once in a while, enjoy it, no need to switch. If butter is the only fat you use, time to branch out, but I don’t think margarine is strictly necessary. If you use margarine right now, read the labels carefully, avoid anything that has “hydrogenated” in the ingredients list, and look for options with a smaller omega-6 to omega-3 fat ratio.
I am still going to use margarine at home, though I feel less convinced that margarine is better. We are trying to reduce our animal product intake for ethical and environmental reasons, and butter is simply not vegan.