The science behind the savory flavor enhancer that sparked a decades-long health myth
Monosodium glutamate, or MSG, is a simple sodium salt of glutamic acid that intensifies the savory taste of food. Despite its reputation for causing discomfort, international health bodies consider it safe. Its journey from a Japanese seaweed extract to a global kitchen staple is a story of chemistry and misconception.
In 1908, Japanese biochemist Kikunae Ikeda sought to isolate the savory quality of kombu, a seaweed used in traditional dashi broth. By experimenting with various glutamate salts, he identified monosodium glutamate as the most palatable and soluble option. He patented the process, and by 1909, the Suzuki brothers began commercial production under the brand Ajinomoto, meaning essence of taste.
The modern industrial production of MSG has evolved through three distinct phases: the hydrolysis of vegetable proteins from 1909 to 1962, direct chemical synthesis using acrylonitrile from 1962 to 1973, and the current method of bacterial fermentation. Today, Corynebacterium species are cultured with carbohydrates from sources like sugar beets or molasses to produce L-glutamate, which is then neutralized with sodium.
The persistent belief that MSG causes Chinese restaurant syndrome lacks robust scientific backing. While anecdotal reports of headaches or discomfort exist, blinded, placebo-controlled studies have consistently failed to demonstrate a causal link when MSG is consumed with food. Even in extreme cases, such as the 2000 study of 130 self-identified sensitive subjects, researchers found no reproducible response to the additive.
Regulatory bodies, including the U.S. Food and Drug Administration, classify MSG as generally recognized as safe. While some regions have historically restricted its use—such as a temporary ban in Pakistan's Punjab Province between 2018 and 2024—these decisions have been reversed following expert reviews of the scientific evidence. Humans naturally metabolize glutamate, and dietary intake does not increase brain glutamate levels or impair cognitive function.
Source: Monosodium glutamate
