Whether butter or margarine are healthier has been a debate that has raged since the invention of margarine.

Before 2015, when margarines were filled with now-banned trans fats, that was a strong reason to opt for butter.

For more information on that, see: A Word About Trans-Fatty Acids (TFAs) ← when you click this one, you’ll need to scroll down slightly for the bit about trans fats.

Nowadays, the macronutrient/lipid profiles are generally more similar (although margarine usually has less saturated fat), except one thing that butter has in its favor: more micronutrients. What exactly they are (and how much) depends a lot on the diet and general health of the cows* from whom the milk to make the butter came, but they’re not something found in plant-based butter alternatives at this time.

*It is easy to think “yes, but grass-fed happy cows who skip gaily through the meadows during the day and the farmer tucks them into bed at night etc produce the best milk, and therefore the best butter”, and that is notionally true (if you’ll pardon the exaggeration of the scene). However…. Most people with a) completely forget about that when shopping b) easily fall for greenwashing; if there’s a picture of a meadow on the packet, it must be well-sourced, right? The truth is that almost all dairy produce in N. America comes from factory farms, so assume it’s that unless you see strong evidence to the contrary.

See also: What Health Difference Does Pasture-Raised Beef Actually Make? ← the answer is: negligible difference to the meat, though it does improve the micronutrient profiles of the dairy products.

Nevertheless, because of the saturated fat content, it’s not advisable to use more than a very small amount of either (two tablespoons of butter would put one at the daily limit already, without eating any other saturated fat that day). See also: What’s The Truth? Can Saturated Fats Be Healthy?

For more on the science of butter vs margarine, check out: Butter vs Margarine ← notwithstanding the title, this wasn’t a “This or That” article, it’s a mythbusting edition article!

The “Appeal to Nature” fallacy

Broadly speaking, it is well-established that:

• a minimally-processed whole-foods plant-based diet is a very healthful way of eating for most* people
• a diet high in ultra-processed foods is almost** always terrible for the health

*See: Do We Need Animal Products To Be Healthy? ← for most people no, for some, yes

**There is nuance here:

• See, on the one hand: How Likely Is It That Ultra-Processed Foods (UPFs) Will Kill You? ← answer: it is alarmingly likely
• But on the other hand: Are plant-based burgers really bad for your heart? Here’s what’s behind the scary headlines ← answer: they’re not fabulous, but they’re generally better than their animal-based equivalents, and certainly rarely worse

And yet, sometimes what is natural is not what is healthiest, and the “appeal to nature” fallacy is what goes wrong in a person’s logic when thinking “it’s natural, so it must be healthy” or, conversely, “it’s unnatural, so it must be healthy”.

You know what else is natural? Smallpox. You know what else is unnatural? Refrigeration.

So, putting assumptions either way aside, it’s been interesting to see some recent science on margarine and similar spreads.

A team of scientists (Dr. Wendy Hall et al.), examined whether (and if so, how) industrially processed interesterified (IE) fats—common in margarines, spreads, and bakery foods—affect heart health.

Specifically, IE fats rich in palmitic acid (from palm oil) and stearic acid (from other plant sources) were compared as substitutes for trans fats and animal fats.

What they checked for: cholesterol, triglycerides, insulin sensitivity, liver fat, inflammation, and blood vessel function were all assessed, over the course of the 6-week trial (which yes, is certainly long enough to establish the impact of dietary choices on those metrics, though of course longer is always better), during which their diets were tailored to include 10% of their daily calories as the fat type being tested.

What they found: no significant differences were found between the two fat types in blood cholesterol or triglyceride levels, including the total-to-HDL cholesterol ratio (a key indicator of heart disease risk), and no adverse effects were observed on inflammation, insulin resistance, liver fat, or vascular function.

In the lead researcher’s own words:

❝Our findings provide reassuring evidence that industrially processed fats currently used in everyday foods, whether rich in palmitic or stearic acid, are unlikely to have harmful effects on cardiovascular health when consumed in amounts that people could achieve in their everyday diets. ❞

~ Dr. Wendy Hall, lead researcher of the study

And to quote her colleague,

❝With the current demonization of everything processed, this research highlights that not all food processing is bad for us.

The process of interesterification allows the generation of hard fats in place of harmful trans fats, while also enabling manufacturers to reduce the saturated fat content of spreads and foods. Given the widespread use of the process of interesterification of fats and the fearmongering around food processing, this research is timely.❞

~ Dr. Sarah Berry, senior author of the study

Read in full: The effects of consumption of interesterified fats rich in palmitic acid compared with stearic acid on intermediary markers of cardiometabolic disease risk: a randomized controlled trial in healthy adults

Want to learn more?

If you want to get back to basics in the healthiest way, consider expanding your knowledge of the various cooking oils at your disposal:

Butter vs Plant Oils: What The Latest Evidence Shows ← includes a stack of head-to-heads that we’ve done in our “This or That” section, plus some very strong science

Enjoy!