MSG controversy explained

Monosodium glutamate (MSG) has been controversial for decades. The additive has traditionally been viewed as unhealthy or even dangerous, with many consumers distrusting it. Yet a growing body of evidence indicates that the links between MSG and adverse health effects are not as strong as once thought. MSG is a flavour enhancer that intensifies umami flavours in food. It is commonly used in manufactured foods ranging from crisps and canned vegetables to soups and meats. MSG also naturally occurs in a range of foods, such as tomatoes and some cheeses. Its use is particularly widespread in Asia. According to analytics company Mintel, 28% of food launches in Asia Pacific contained MSG between 2020 and 2024, compared to just 5% in Europe. For decades, MSG has been the source of significant controversy. While it is considered safe by food agencies around the world, the additive “has a degree of stigma attached to it”, says Julia Mills, food and drink analyst at Mintel. The controversy is an old one. In 1968, a letter to the New England Journal of Medicine spoke of symptoms of numbness, weakness and palpitations following consuming food in a Chinese restaurant. These symptoms, assumed to be an adverse reaction to MSG, were branded ‘Chinese restaurant syndrome’ due to the additive’s association with Chinese cuisine. The term is now considered offensive , and the link between MSG and the symptoms it describes found to be weaker than presented. Yet consumers are still wary of the additive. As recently as last year, 45% of consumers in the US – 50% of baby boomers and 42% of Gen Z – avoided MSG, according to Mintel. There is also growing demand for the use of substitutes, such as porcini mushroom seasonings (using fermentation) and anchovy stock, and food companies have reformulated their products to contain less of the additive. But decades later, what does the research say about the health risks of MSG? Despite the persisting distrust of MSG among consumers, and efforts to reformulate it away among manufacturers, MSG has been scientifically reassessed in recent years. By the 1990s, the Federation of American Societies for Experimental Biology (FASEB) had already concluded that side effects, such as numbness, drowsiness and palpitations, were not only mild and short-lived, but associated with large doses of MSG, more than three grams. Most recipes in fact call for small amounts – a typical serving of a food with MSG contains less than 0.5 grams, according to the US Food and Drug Administration (FDA). Years later, studies are repeatedly suggesting that MSG is not as harmful as many believe. A review of studies on the topic found that many adverse health effects associated with MSG consumption, such as cardiotoxicity, hepatotoxicity, neurotoxicity, and low-grade inflammation, are linked to amounts much larger than those normally consumed in food products. Another study explored claims linking MSG to worsened asthma symptoms . It found instead that those consuming products containing MSG experienced no worse symptoms than those taking the placebo. This was the case both for those who believed that MSG worsened their asthma, and those who did not. Some have even pointed to benefits from consuming MSG. Some have suggested that it could an alternative to table salt, as it contains only one-third of the sodium that table salt does. Nevertheless, symptoms such as headaches, nausea and fatigue are still found among some sensitive consumers when eaten in large quantities, points out Neha Srivastava, senior patent analyst for food, drink, beauty and personal care at Mintel. Furthermore, foods that contain MSG are also “often heavily processed, with unhealthy nutrition profiles characterised by high levels of sodium or fat”, she says. Scepticism still surrounds MSG, particularly among older consumers. Yet the additive has frequently been found innocent of the charges that are levelled against it.