Low-Glutamate Diet Linked to Fewer Migraines

By Pat Anson

A diet low in glutamate significantly reduced migraines in U.S. veterans with Gulf War Illness, according to a new study that documents for the first time that a reduction in migraine symptoms is linked to changes in the brain.  

Glutamate is an amino acid used in food additives like monosodium glutamate (MSG), which is widely used in processed food and soups as a flavor enhancer. Previous studies have shown that a low glutamate diet reduces pain and other symptoms from fibromyalgia.   

Researchers at Georgetown University Medical Center observed a “big, big decrease” in migraines in 40 veterans with Gulf War Illness a month after they were put on a low-glutamate diet. Like fibromyalgia, Gulf War illness causes an array of musculoskeletal, gastrointestinal, and neurologic symptoms, including migraines. It is thought to be caused by exposure to toxic chemicals during the war.

“More than half of the Gulf War veterans had migraines before the diet, and that dropped to under 20% after following the diet for one month,” said senior author Ashley VanMeter, PhD, Professor of Neurology at Georgetown University School of Medicine. “So it was a very significant drop.”

In addition to fewer migraines, veterans on the low-glutamate diet also had significant reductions in widespread body pain, fatigue, mood issues, and cognitive dysfunction. 

Findings from the study were recently presented at the annual meeting of the Society for Neuroscience in San Diego. The research, funded by the U.S. Department of Defense, grew out of a collaboration with Kathleen Holton, PhD, a nutritional neuroscientist at American University, who has been researching the low-glutamate diet as a way to manage neurological conditions. 

In addition to food additives, glutamate occurs naturally in foods like tomatoes, cheese, mushrooms and nuts. Glutamate acts as a neurotransmitter in the brain and is believed to stimulate nerve cells that process pain signals. 

In the Georgetown University study, researchers used brain scans to compare differences in the visual cortex – the part of the brain that processes visual information – in patients with Gulf War Illness and a group of healthy patients. Those with Gulf War Illness had a thicker right visual cortex and were more likely to report migraines than the healthy control group. 

But after being put on a low glutamate diet, the brain scans of Gulf War Illness vets showed a significant reduction in cortical thickness.

Holton says the findings support the theory that glutamate may damage nerve cells, causing a repetitive cycle of neuroinflammation and oxidative stress in the brain. 

“We think this is one of the reasons people who are susceptible to dietary glutamate tend to have prolonged symptoms over time,” said Holton.  

Thickening of the visual cortex is common among migraine sufferers, especially those whose migraines occur with aura, or visual disturbances. That raises the question of whether a low-glutamate diet could be an inexpensive treatment option for patients with migraine or fibromyalgia..  

“This is a very doable diet,” VanMeter said. “It’s a healthy diet, it’s not that hard to follow, and it’s a very low-cost way of treating what for some individuals is a chronic and debilitating condition.” 

Holton noted that the study also adds to a growing body of evidence about how processed foods impact health.

“This speaks to the fact that diet can not only make us sick, but can also acutely treat our symptoms,” she said.

The FDA considers MSG to be “generally recognized as safe,” although some people are sensitive to it and experience short-term, mild symptoms, such as headache, numbness, flushing, tingling, palpitations, and drowsiness.

“Over the years, FDA has received reports of symptoms such as headache and nausea after eating foods containing MSG. However, we were never able to confirm that the MSG caused the reported effects,” the agency says.

How Chronic Pain Disrupts Emotions

By Pat Anson, PNN Editor

Does waking up with pain everyday put you in a bad mood? Do you lose your temper easily or worry a lot?

It could be a sign that chronic pain has created a chemical imbalance in your brain that makes it harder for you to keep negative emotions in check, according to a new study by Australian researchers.

“Chronic pain is more than an awful sensation,” says senior author Sylvia Gustin, PhD, a neuroscientist and associate professor at the University of Sydney’s School of Psychology. “It can affect our feelings, beliefs and the way we are. 

“We have discovered, for the first time, that ongoing pain is associated with a decrease in GABA, an inhibitive neurotransmitter in the medial prefrontal cortex. In other words, there's an actual pathological change going on.”

Gustin and her colleagues at Neuroscience Research Australia (NeuRA) used advanced neurological imaging to scan the brains of 48 people. Half of them lived with a chronic pain condition, while the other half had no history of chronic pain and served as a control group.

Their findings, recently published in the European Journal of Pain, showed that participants with chronic pain had significantly lower levels of GABA than the control group – a pattern that was consistent regardless of the type of chronic pain. 

Neurotransmitters help communicate and balance messages between cells in the brain and central nervous system. While some amplify signals (excitatory neurotransmitters), others weaken them (inhibitive neurotransmitters). GABA, or γ-aminobutyric acid, is one of the latter. It acts in the brain as emotional regulator that helps dial down our emotions.

“A decrease in GABA means that the brain cells can no longer communicate to each other properly,” Gustin explained in a news release. “When there’s a decrease in this neurotransmitter, our actions, emotions and thoughts get amplified.”

While the link between chronic pain and decreased levels of GABA has previously been found in animals, this is the first time it’s been demonstrated in humans. Gustin hopes the findings will encourage people with chronic pain who may be experiencing mental health issues. 

“It's important to remember it’s not you – there’s actually something physically happening to your brain,” she says. “We don't know why it happens yet, but we are working on finding solutions on how to change it.”

GABA is not the only neurotransmitter that’s impacted by chronic pain. In a previous study, Gustin and her research team found that levels of glutamate, the main excitatory neurotransmitter, are also lower than average in people with chronic pain. Low glutamate levels are linked to increased feelings of fear, worry and negative thinking.

“Together, our studies show there's really a disruption in how the brain cells are talking to each other,” says Gustin. “As a result of this disruption, a person’s ability to feel positive emotions, such as happiness, motivation and confidence may be taken away – and they can’t easily be restored.” 

Medication can help relieve chronic pain, but there are currently no drugs that directly target GABA and glutamate levels in the brain. Gustin and her team are developing an online emotional recovery program as a non-pharmaceutical option for treating neurotransmitter disruption. 

“The online therapy program teaches people skills to help self-regulate their negative emotions,” says Gustin. “The brain can't dampen down these feelings on its own, but it is plastic – and we can learn to change it.”