I don’t think some of these things are true. I found a lengthy review from a few years ago. This is by no means a debunking because the science may have changed since then, and it’s only one source:
MSG is found in high-protein food products, such as meat or fish, and also in certain types of cheese (Roquefort and Parmesan) or vegetables (tomatoes, mushrooms, broccoli)
It’s not just meat, but many foods contain MSG. I don’t think our body has any reason to associate it with one specific source.
MSG is supplemented in many processed foods (Conn, 1992; Scopp, 1991), with an estimated average daily human intake of around 0.3–1.0 g in European industrialized countries (Beyreuther et al., 2007).
The review offers the following table:
Table 1. Food additives NOAEL and ADI values
Food additive
NOAEL
ADI
MSG
3200 mg/kg
30 mg/kg
This means that a small adult of 70 kg would need to ingest 2.1 g to surpass the recommended dose. That’s 3 times the Acceptable Daily Intake and about 80 times below the toxic level to begin feeling intoxicated. The study also notes that you need to eat it a lot for long periods to have an effect. They even conclude:
we posit that many of the reported negative health effects of MSG have little relevance for chronic human exposure to low doses.
Not to mention that not all of the MSG you consume gets into your system:
Only a very small quantity is subsequently found in the portal blood and, most likely, this originates from glutamine catabolism as a result of intestinal glutaminase activity, rather than from the absorption of dietary glutamate (Battezzati, Brillon, & Matthews, 1995).
In healthy human volunteers, nearly all of the enterally delivered glutamate is removed by the splanchnic bed on the first pass (Matthews, Marano, & Campbell, 1993)
This means that your body filters MSG as it’s absorbed, and that most of the glutamate found in the blood is a byproduct of what’s already in your body.
Another point to note is that its effect is largely dependent on the type of food you eat. You can’t generalize that it’ll have the same effect every time.
Besides its well-known impact on food palatability, MSG enhances salivary secretion and interferes with carbohydrate metabolism, while the impact on satiety and post-meal recovery of hunger varied in relation to meal composition.
(Note that the interference with sugar metabolism may be related to higher doses, according to preclinical studies summarized in Table 4)
And yes, it has a great effect on taste.
In addition to its basic specificity, the umami taste can enhance overall flavor intensity and improve food palatability. This effect is dependent on a variety of factors, the most important being the concentration of umami molecule and the food matrix (Masic & Yeomans, 2013).
This is probably because it’s incorporated as an additive and adsorbed onto the surface of food, which means the molecules are free to interact with your taste receptors first, but this is only my opinion.
I don’t think some of these things are true. I found a lengthy review from a few years ago. This is by no means a debunking because the science may have changed since then, and it’s only one source:
It’s not just meat, but many foods contain MSG. I don’t think our body has any reason to associate it with one specific source.
The review offers the following table:
Table 1. Food additives NOAEL and ADI values
This means that a small adult of 70 kg would need to ingest 2.1 g to surpass the recommended dose. That’s 3 times the Acceptable Daily Intake and about 80 times below the toxic level to begin feeling intoxicated. The study also notes that you need to eat it a lot for long periods to have an effect. They even conclude:
Not to mention that not all of the MSG you consume gets into your system:
This means that your body filters MSG as it’s absorbed, and that most of the glutamate found in the blood is a byproduct of what’s already in your body.
Another point to note is that its effect is largely dependent on the type of food you eat. You can’t generalize that it’ll have the same effect every time.
(Note that the interference with sugar metabolism may be related to higher doses, according to preclinical studies summarized in Table 4)
And yes, it has a great effect on taste.
This is probably because it’s incorporated as an additive and adsorbed onto the surface of food, which means the molecules are free to interact with your taste receptors first, but this is only my opinion.
A review of the alleged health hazards of monosodium glutamate (Zanfirescu et. al 2019)
https://pmc.ncbi.nlm.nih.gov/articles/PMC6952072/
But I’m still curious, where did you learn about this mechanism related to meat?