Monosodium glutamate harms and protective natural products
What it found
In animal and lab studies, monosodium glutamate has been linked to obesity, diabetes, liver damage, brain effects and reproductive problems.
Some plant extracts and vitamins reduced these effects in the same kinds of studies.
What they found
Animal and lab studies
Liver and oxidative stress
In rats and mice, monosodium glutamate raised markers of oxidative stress and lowered antioxidant enzymes, leading to liver damage. These effects were seen at doses from 0.6 mg/g body weight and above.
Brain and nerves
In rats, monosodium glutamate damaged neurons in the hypothalamus and impaired memory and learning. It also caused anxiety-like and depressive-like behaviours and metabolic changes.
Male fertility
In male rats, monosodium glutamate caused damage to the testes, lower testosterone, and fewer sperm. These changes could affect male fertility.
Protective natural products
In animal studies, extracts of Calendula officinalis, Curcuma longa, green tea, Ginkgo biloba, tomato lycopene, ginger, and vitamins C, D and E reduced the harmful effects of monosodium glutamate. They worked by boosting antioxidant defences and reducing oxidative stress and cell death.
Studies in people and animals
Obesity and diabetes
In rats and mice, monosodium glutamate increased body weight, blood glucose, insulin and leptin, and caused fatty changes in the liver. In healthy adults, dietary monosodium glutamate was linked to obesity and overweight.
DNA damage
In lab tests, monosodium glutamate damaged DNA in human white blood cells and in onion root tip cells. In rats, doses of 20 and 40 mg/kg body weight for 2 months caused DNA damage in the mouth lining. Some other researchers found no such damage.
What the authors conclude
“Based on the reviewed studies, it suggests that MSG should be eliminated from diet until its safety is re-examined.”
Also in their conclusions
- They say that monosodium glutamate is still widely used as a flavour enhancer and that many studies have shown unwanted side effects from long-term consumption, making its safety controversial.
- They suggest that monosodium glutamate should be eliminated from the diet until its safety is re-examined.
- They call for more detailed studies to understand the mechanisms behind the serious health risks of monosodium glutamate.
How it was done
The authors wanted to summarise what is known about the toxicity of monosodium glutamate and whether natural products can protect against it.
They searched scientific databases for published articles on the chemistry and toxicity of monosodium glutamate and the protective effects of natural products, up to August 2019.
What it can’t tell you
- Most of the evidence comes from animal and lab studies, so the results may not be the same in people.
- The review includes some human studies, but these can show links, not cause and effect.
- The doses used in many animal studies are higher than what people typically eat.
Who paid
- Authors work at
- Mashhad University of Medical Sciences, Iran
The paper
- Title
- Natural products as safeguards against monosodium glutamate-induced toxicity
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Hajihasani MM, Soheili V, Zirak MR, Sahebkar A, Shakeri A (2020). Natural products as safeguards against monosodium glutamate-induced toxicity. Iranian journal of basic medical sciences. doi:10.22038/IJBMS.2020.43060.10123Free full textPubMed 32489556DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error