Monosodium glutamate, or MSG for short, is a food additive commonly added to Asian food and ready-made meals. This does make the food taste better, and is common in many processed foods. Glutamate is also a neuro-transmitter, while sodium is an atom found in the composition of salt. So, on the surface, monosodium glutamate looks rather innocuous.
Although a cursory look at the scientific literature on MSG and cancer returns very little results, there are other clues that point to the direction of caution:
- Monosodium glutamate has been shown to promote leptin resistance (study). Leptin is the satiety hormone, and leptin resistance means your body doesn’t know as well as before when it has enough energy stored. As a consequence, monosodium glutamate will cause obesity. And high leptin (a consequence of leptin resistance) has been found in several cancers (study). Although this is more of a correlation than a causation, it is definitely indicating that caution is needed.
- More importantly, monosodium glutamate is often given to lab rats to make them obese. This is because MSG induces insulin resistance in them (study, study, study). It also increases insulin secretion in humans (study). This is critical, as insulin resistance is one issues at the core of the metabolic cause of cancer.
- Finally, monosodium glutamate seems to alter the cells mitochondria (study) and increase their reactive oxygen species (study). And as discussed elsewhere on this website, damaged mitochondria are another core cause of cancer.
As a more minor point, there is the question of purity of the molecule of MSG as produced by the industry, with the potential presence of carcinogenic compounds such as mono and dichloro propanols and heterocyclic amines as a direct consequence of the processing (source).
So what to do about it?
I don’t like to be too orthorexic about what people eat. And if the occasional meal at the Chinese restaurant is what it takes to get the family together and have a good time, then MSG become a small issue not really worth concerning about.
On the other hand, if you have to rely heavily on ready-made food and takeaways, then be mindful that monosodium glutamate may be a contributing factor to cancer. This is part of the reasons why one of my first advice to any cancer patient is to ditch the processed food. Also if you have some MSG in your food pantry, now is a good time to bin it.