Over the past three decades, there has been a significant global surge in the demand for monosodium glutamate (MSG), a widely used food additive.
MSG is a naturally occurring non-essential amino acid found in various foods such as meats, seaweed, anchovies, mollusks, tomatoes, cheeses, vegetables, and shellfish. While many foods naturally contain MSG, its consumption becomes problematic when added in larger amounts to industrially processed food products.
The global demand for MSG has exceeded three million metric tons, with a market value surpassing $4.5 billion. Asia, especially China, dominates both consumption and production, accounting for over three-quarters of the world's MSG consumption. Annual global demand saw an almost four percent increase before 2020, and future projections point to a surge in demand, particularly in Thailand, Indonesia, Vietnam, and China, with subsequent increases expected in Brazil and Nigeria.
Despite MSG's popularity in enhancing flavor, research emphasizes potential health risks associated with excessive consumption. High levels of MSG intake have been linked to metabolic disorders such as obesity, diabetes mellitus, and hypertension. Safety concerns surrounding MSG have fueled academic interest, especially given its widespread use in prepared food and Chinese cuisine.
This study by university researchers highlights the safety controversy surrounding MSG, and addresses health risks associated with its excessive consumption. Their research methodology involves an extensive review of scientific studies and literature related to MSG consumption and its effects on metabolic health, with a focus on prominent usage in regions like Asia.
For example, the study references research by Kasozi et al., which explores the impact of varying MSG concentrations (5%, 1%, 0.2%, 0.04%) on metabolic parameters and longevity using male Drosophila melanogaster over 30 days. Their findings suggest that concentrations of MSG below 5% are safe when consumed in foods, though higher concentrations may affect tissue health.
MSG excitotoxicity, believed to result from excessive glutamate receptor stimulation, triggers events leading to neuronal death through free radical production. MSG induces lipid peroxidation, a marker for oxidative stress, suggesting its potential role in the development of metabolic disorders.
Additionally, MSG consumption has also been linked to increased cellular lipogenesis, contributing to obesity. The effects of MSG vary by dosage, with lower doses improving energy balance and homeostasis, while excessive consumption may lead to metabolic disorders.
In summary, MSG has a pronounced tendency to trigger the development and progression of metabolic disorders such as obesity, cancer, hypertension, and diabetes mellitus. This occurs through various metabolic mechanisms, including the induction of oxidative stress, hyperinsulinemia, dyslipidemia, hyperleptinemia, hyperphagia, dysfunction of GLUT transporters, and pro-proliferative action.
Depending on the dosage, MSG can exhibit both advantageous and detrimental effects. Lower doses contribute to enhanced energy balance and homeostasis, while excessive consumption may initiate metabolic disorders.
Despite safety concerns, MSG continues to be widely consumed globally. The researchers recommend minimizing its use as a flavouring agent and emphasising the need for further research on the biochemical effects of long-term consumption by humans.