Does MSG Cause Chronic Pain?

By Pat Anson, Editor

Monosodium glutamate (MSG) is a naturally occurring amino acid that is widely used in processed food and soups as a flavor enhancer. There have been many anecdotal reports of MSG causing headaches, nausea and fatigue – but the Food and Drug Administration found no evidence of that and declared that MSG is “generally recognized as safe.”

A small pilot study in central Africa suggests otherwise.

Researchers at the University of Michigan and American University in Washington DC wanted to know why so many people in Meru, Kenya have widespread chronic pain – nearly two-thirds according to one survey. Most suffered from neurological problems, including headaches or migraines, chronic fatigue, cognitive dysfunction, and sleep issues.

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Researchers recruited 30 Meru residents for a study to see if diet and dehydration played a role in their symptoms, focusing on a local seasoning spice called mchuzi mix, which often contains MSG. The spice mix is known as the “flavor of Kenya” and is commonly used in multiple dishes throughout the day.

When some of the study participants were sent home with a mchuzi mix containing no MSG and urged to drink more water, they started showing significant improvement in their pain symptoms within two weeks. Many liked the flavor of the new mix and asked for more.

"This preliminary research in Kenya is consistent with what I am observing in my chronic pain research here in the United States," said Kathleen Holton, PhD, a nutritional neuroscientist at American University and lead author of the study published in the journal Nutrition.

"We don't know what exposure is leading to this susceptibility to dietary glutamate, but this pilot study suggests the need for a large-scale clinical trial, since dietary change could be an effective low-cost treatment option for developing countries."

Holton and her colleagues believe glutamate may act as a neurotransmitter in the brain and stimulate nerve cells. Increased consumption of glutamate may also enhance the central sensitization that leads to chronic pain.

“These preliminary findings support the hypothesis that MSG may be able to modulate pain response, and suggest that a future larger study is feasible and warranted in this population,” said Holton.

Researchers are planning a larger epidemiological survey to understand the prevalence of widespread chronic pain in the region and to train Kenyans on how to conduct a large-scale clinical trial. The goal is to see if dietary change could be an effective, low-cost treatment option for chronic pain.

"This would be incredible if we could impact chronic pain simply by making slight modifications to diet," said Daniel Clauw, MD, a University of Michigan professor and a leading expert on chronic pain.