From cheap butter substitute to supposedly healthy alternative: the science behind margarine
It has the look and color of butter, it's in the refrigerated section right next to the butter but ... it's not butter. Born in Napoleonic France as a more affordable alternative, margarine is consumed at breakfast under the pretext of being healthier due to its vegetable origin. But is it really?
The origin of margarine
Although we can now go to the supermarket and find a wide variety of products and alternatives, this has not always been the case. Margarine originates from 19th century France, where Emperor Napoleon III was on the lookout for a cheap substitute for butter that could be preserved over time without losing its nutrients ("corps gras semblable au beurre, mais de prix inférieur, apte à se conserver longtemps sans s'altérer en gardant sa valeur nutritive).
A pharmacist came up with the recipe for margarine emulsifying fractionated beef fat, with milk and water, which he called oleomargarine, a very long and unprofessional name that ended up being shortened to the term we use now. It was patented in 1872, but it wasn't until World War II that margarine became popular as a substitute for butter.
How margarine is "made"
It has rained a lot since the pharmacist Hippolyte Mège-Mouriés came up with the recipe for margarine, giving way to a large-scale industrial manufacturing in which vegetable-based fat has been replacing animal fat.
And it is that vegetable oils abound in nature and, following Napoleon's premises, there are very cheap ones such as palm oil. However, in the production of margarine corn, sunflower, olive, coconut or peanut oils are used. The problem is that at room temperature they are liquid. So after refining them, they go through a process called hydrogenation, key in this story.
Hydrogenation saturates the oil partially or totally with hydrogen to alter its melting point, achieving a specific solids curve. Or what is the same: it makes the oils more stable, achieving a solid texture similar to those of animal origin and minimizing oxidative rancidity.
In a simplified way, oils are long chains of long acids made up of carbon atoms bonded together. If each carbon atom is attached to two carbons and two hydrogens (via single bonds), then it is saturated and solid at room temperature. It is the case of butter.
But if the carbon atoms are linked together with double bonds, then they are unsaturated. If we add hydrogen atoms, nickel as catalyst and certain temperature conditions "to the cocktail shaker", then this carbon double bond breaks and each carbon atom joins two hydrogen atoms, saturating each other. We already have the margarine.
Side B of this process is the way the hydrogen atoms are placed: instead of being on the same side of the chain, they are on opposite sides, forming trans fatty acids. This configuration is rare in nature, with hydrogenated vegetable oils from the food industry being the main source.
However, not all vegetable oils are the same: olive oil better supports this process thanks to the stability given by its greater presence of monounsaturated acids, something that hinders its oxidation to produce trans fats.
The partial hydrogenation process generates high amounts of trans fatty acids, for this reason in the last decades the margarine industry has been changing this process towards others such as total hydrogenation, interesterification and fractionation, achieving percentages of less than 1%. But why is reducing trans fatty acids so important?
Margarine vs. butter from a nutritional point of view
The main ingredient in margarine is fat. They can be exclusively from vegetable oils or with a part of animal origin, known as mixed. The second ingredient in percentage terms is water, creating an emulsion of the mixture of both. Since water and fat are immiscible, food additives that act as emulsifiers help in this task. Among them we find mono and diglycerides of fatty acids and lecithin. In the manufacture of margarine, salt and potassium sorbate, a preservative, are also added.
As for their contribution of vitamins and minerals, they are enriched in fat-soluble vitamins such as A, D and E and, in case the manufacturer replaces part of the water with skimmed milk, we will also find calcium as a mineral.
Although there are differences between the commercial brands and the types of margarine marketed (there is 3/4 margarine, light margarine), the nutritional composition of butter and "standard" margarine according to the Spanish Federation of Nutritionists is as follows:
Total lipids (g)
Cholesterol (mg / 1000 kcal)
Calcium (8mg), Iron (0.2mg), Magnesium (1mg), Iodine (26 microg), Sodium (800mg), Potassium (7mg),
Calcium (15mg), Iron (0.2mg), Magnesium (2mg), Zinc (0.15mg), Iodine (38 microg), Sodium (5mg), Potassium (16mg), Phosphorus (15mg)
A (900 microg) and E (8mg)
A (828 microg), D (0.76 microg) and E (2mg)
We have made the table with 100 grams, but the usual dose is about 15 grams. As you can see, the amount of fat we eat while eating butter or margarine is very similar: it is around 80%. The differences lie in the origin and quality of it.
With butter we are taking saturated fats from animal sources, which increase bad cholesterol, favor obesity and the possibility of cardiovascular disease, according to the WHO. Of course, butter is not the healthiest thing we can put on toast.
With margarine we also take saturated fats, but given their vegetable origin, they are richer in mono and polyunsaturated fatty acids than in saturated ones. The problem is that, unless otherwise noted, margarine contains more trans fats. The way in which it is obtained returns to the fore.
There are two sources of trans fatty acids: natural and industrial. They are naturally present in small amounts in the muscles and milk of ruminants, hence 5% of their consumption comes from the intake of products such as butter, cream, whole milk or fatty meat. But the bulk of trans fat comes from the partial hydrogenation of vegetable oils, something that we consume in industrial pastries, pre-cooked foods, snacks, fried foods, ice creams or smoothies. Margarine is included in this group of foods with trans fat of industrial origin.
When trans fats pass into the blood, they promote the increase of bad cholesterol to the detriment of the good one, the development of arteriosclerosis, they increase the levels of triglycerides in the blood - which favor cardiovascular diseases -, they contribute to diabetes ... its effects negative to health are higher than those of saturated fats, hence the World Health Organization recommends that while the intake of saturated fat should represent less than 10% of total calories, the intake of trans fat should be less at 1%. In fact, the WHO plans to eliminate trans fat from the food industry by 2023.