Monosodium glutamate and brain development in rats fed before birth
What it found
Rats fed monosodium glutamate from before birth through 90 days of age showed no clear signs of harm to brain development.
The authors say the study does not support changing daily intake limits.
What they found
Animal and lab studies
Swimming development in pups
Two effects appeared in swimming tests in rat pups. One was an improvement and the other was a small, unusual delay that the author judged unimportant.
Avoidance learning tasks
In rat pups, two avoidance-learning effects appeared but only in one sex at one dose each. The author says these did not form a consistent pattern.
Other behaviour tests
One passive-avoidance result in rat pups was actually an improvement rather than a problem. Another test showed more standing up without matching changes in movement.
Other findings
Daily intake limits
The author concludes the 1979 rat data do not support setting a new daily intake limit for monosodium glutamate based on this study.
What the authors conclude
- They conclude there is no evidence in these rat data that dietary monosodium glutamate harms brain development.
- They state the study provides no basis for establishing a new daily intake limit for monosodium glutamate.
How it was done
A 1979 rat study was recently used to set a new daily intake limit for monosodium glutamate as a food additive. The author re-examined that original work to check if it truly supported the change.
The author re-evaluated a 1979 study where pregnant rats were fed diets with 0, 1.7, 3.4, or 5.1% monosodium glutamate. The same diets were given to their pups until 90 days old. About 18 to 20 litters were tested at each dose, using 21 behavioural tests and 10 body or tissue checks.
What it can’t tell you
- We summarised it from the abstract only.
- These results come from rats, so they cannot show what happens in people.
- This is a re-analysis of one older study, so it cannot capture newer research on the topic.
Who paid
- Authors work at
- University of Cincinnati College of Medicine and Division of Neurology, USA
The paper
- Title
- A Test of Dietary Monosodium Glutamate Developmental Neurotoxicity in Rats: A Reappraisal
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Animals and lab studies
- Summarised from
- Abstract only
- Cite
- Vorhees CV (2018). A Test of Dietary Monosodium Glutamate Developmental Neurotoxicity in Rats: A Reappraisal. Annals of nutrition & metabolism. doi:10.1159/000494781PubMed 30508817DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error