Magnesium stearate is a mixture of magnesium salts of fatty acids obtained from fats and oils usable in food (whether of animal or vegetable origin).
The product consists mainly of magnesium stearate and palmitate in varying proportions, which is used as an additive in the food industry.
Food additives are defined as:
“Substances that are added to foods with a technological purpose (to improve their appearance, texture, resistance to microorganisms, etc.) at different stages of their manufacture, transport or storage” (AESAN, n.d.).
It’s manufactured either through a direct or indirect production processes.
What magnesium stearate is used for in food supplements
Magnesium stearate has the appearance of a white/off-white powder, very fine, with a greasy texture, practically insoluble in water, but soluble in ethanol and ether.
It’s mainly used as an anti-caking agent, which is the main function it plays in food supplements; in addition to being an emulsifier, mainly in sweets, gum, herbs and spices and pastry ingredients.
An emulsifier is a substance that makes it possible to form or maintain a homogeneous mixture of two or more non-mixables, such as oil and water, in a foodstuff.
Is magnesium stearate harmful to health?
The European Food Safety Authority re-evaluated the additive, following a request from the European Commission to do so, as the first safety evaluation of this additive, and it was established as safe, in 1991.
In this 34-page safety report, EFSA assessed the available information on the additive, which is derived from stearic acid (E-470):
- Magnesium stearate seems to dissociate in the gastrointestinal tract, so in the end we’re absorbing magnesium + fatty acids. Nutrients that are safe and widely used in the normal Western diet.
- With the available data on genotoxicity (cancer risk and mutation), there is no cause for concern.
- There is no information to cause alarm on chronic, subchronic, reproductive or developmental toxicity from the use of this additive.
The expert group concluded that:
“There is no need to establish an Acceptable Daily Intake (ADI) for the additive as it does not pose a safety concern at the use levels reported in the food industry” (EFSA, 2018).
The FDA classifies it as a completely safe GRAS substance used in small amounts as an additive in tablets.
Myths about the health hazard of magnesium stearate in foods and supplements
Additives are wrapped in a halo of mysticism and pseudoscience, which characterise them them as harmful compounds.
This trend has been fuelled by confusing chemophobic messages in society that, despite having insufficient scientific backing, results in beliefs such as:
“Sucralose causes disease”
The reality is that any additive used in the food industry is used in a controlled, regulated and legislated manner.
Always for use in foods in which it is expressly authorised and in permitted amounts.
Magnesium stearate has been just one of many additives unfairly affected by these beliefs.
So safe, in fact, that no maximum amount of use is needed to ensure this safety, as even with the heaviest use, the nutritional exposure of any individual to the consumption of this additive is not dangerous to any degree.
Why do food supplements include magnesium stearate?
Its main function as an anti-caking agent is what makes it so widely used in food supplements.
Anti-caking agents (such as magnesium stearate) reduce the tendency of particles in food products to adhere to each other.
This means the powder contained in a capsule, for example, won’t turn into block when the steam from a pot in the kitchen is dispersed into the environment, increasing the humidity in the room where the supplement is stored.
In short, magnesium stearate is used for food safety reasons, to ensure the product is suitable for user experience, preventing it from spoiling if the preservation isn’t optimal (which it never is), and thus allowing us to enjoy the optimal properties of the compounds we purchase, safely and effectively.
- Aesan – Agencia Española de Seguridad Alimentaria y Nutrición. (s. f.). Retrieved October 3, 2022, fromhttps://www.aesan.gob.es/AECOSAN/web/seguridad_alimentaria/subdetalle/aditivos_alimentarios.htm
- World Health Organization. Joint FAO/WHO Expert Committee on Food Additives. (2016). Safety Evaluation of Certain Food Additives and Contaminants: Eightieth Meeting of the Joint Fao/Who Expert Committee on Food Additives Jecfa. World Health Organization.
- Younes, M., Aggett, P., Aguilar, F., Crebelli, R., Dusemund, B., Filipič, M., Frutos, M. J., Galtier, P., Gott, D., Gundert‐Remy, U., Kuhnle, G. G., Leblanc, J., Lillegaard, I. T., Moldeus, P., Mortensen, A., Oskarsson, A., Stankovic, I., Waalkens‐Berendsen, I., Woutersen, R. A., . . . Lambré, C. (2018, marzo). Re‐evaluation of sodium, potassium and calcium salts of fatty acids (E 470a) and magnesium salts of fatty acids (E 470b) as food additives. EFSA Journal, 16(3).
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