Ian Spohn, ND, is a staff naturopathic doctor for Energique who enjoys challenging the dogmas of both conventional and alternative medicine. He is a passionate supporter of the paleo diet and classical homeopathy.
Few food additives have stirred up more controversy than monosodium glutamate (MSG). Occurring naturally in certain foods, added to almost everything these days, hidden beneath an ever-growing list of deceptive ingredient names, the controversy continues as to whether or not MSG is actually that harmful. Decried on the one hand as an excitotoxin that causes brain lesions in rats, on the other hand a recent study (funded by the Ajinomoto Corporation, a leading manufacturer of MSG) has had the audacity to claim that MSG may benefit people with Alzheimer’s disease![i] Though human studies have never proven a consistent link between MSG and the various symptoms ascribed to it, an abundance of anecdotal reports have blamed it for causing anything from flushing and headaches to asthma and autism. So how bad is it for you, really?
HISTORY OF MSG
Traditional Japanese cuisine makes frequent use of a savory broth called dashi, the secret to which is soaking a piece of seaweed in the water before the broth is prepared. MSG was discovered in 1908 when Japanese scientist Ikeda Kikunae successfully isolated the compound in seaweed which lends dashi its rich, meaty flavor. It was soon after patented and used to enhance the palatability of soldiers’ rations during World War II before being harnessed by the food industry to drive a new generation of processed foods. Nobody in the U.S. really took notice of the fact that MSG was being added to everything until a Chinese-American doctor named Robert Ho Man Kwok submitted a letter to the editor of the New England Journal of Medicine. Describing what he called “Chinese Restaurant Syndrome,” he reported that whenever he would eat at Chinese restaurants in the U.S., hoping no doubt to enjoy a taste of his homeland, he would experience a bizarre constellation of symptoms which included numbness radiating from his neck and back down his arms, weakness, and heart palpitations. As a biomedical researcher, he attributed these symptoms to MSG and claimed that several of his well-educated colleagues were in agreement with him, themselves having experienced similar phenomena after dining in Chinese restaurants. Following his initial claim that eating MSG gave him symptoms lasting up to several hours after meals, many other people soon came out with claims that similar symptoms they had been having, like flushing, headaches, and digestive upset, could all be linked to their consumption of foods which contained, as they now came to discover, added MSG.
A controversy was quick to ensue, which has not yet resolved to this day, wherein the food industry which profits from it and umami-loving foodies who enjoy eating it are quick to defend MSG, heralding it as a harmless boon to mankind that makes everything taste delicious, while health-conscious consumers have gone so far as to label it a “silent killer.” The U.S. Food and Drug Administration has never wavered on its early decision to confer the food additive GRAS status, yet it is officially recognized as a causative substance by the International Classification of Headache Disorders! Both sides have made compelling arguments, the most poignant of which may be summarized below:
ARGUMENTS FOR MSG
- It’s basically just sodium and glutamate, a harmless electrolyte and amino acid ubiquitously present in food.
- It’s already found to be naturally occurring in many foods – parmesan cheese, mushrooms, and tomatoes, for instance.
- Controlled studies have never proven a consistent link between consuming MSG and adverse symptoms.
- It improves the taste of food, increasing its consumption and even enhancing digestion, thereby improving nutritional outcomes in hospitalized patients and the elderly.
- It’s been widely consumed throughout Asia for almost a century; how bad can it actually be?
ARGUMENTS AGAINST MSG
- Not merely an amino acid, glutamate is an excitatory neurotransmitter that has proven toxic to the brain in large doses.
- In the unbalanced quantities supplied by adding purified MSG, it disturbs amino acid metabolism by disrupting the glutamate cycle.
- Since the first report of adverse effects by a Chinese-American doctor, the weight of anecdotal evidence has become overwhelming.
- It promotes the overconsumption of unhealthy, nutrient-poor processed foods, thereby causing a widespread subclinical malnutrition, also known as “Dorito Syndrome”
- Large doses cause brain death in rats; how safe can it actually be?
As with virtually any poison (that is, virtually any substance), the real dangers of MSG depend upon the dose. The majority of natural foods, especially the most delicious ones, do indeed contain free glutamate, and even regular salt can be poisonous if you consume a high enough dose. It also seems to be the case that MSG’s toxicity has a strongly idiosyncratic component, with some people reporting a vastly greater sensitivity to it than others. If someone is sensitive to MSG, the ideal solution would be, of course, for that person to avoid MSG altogether, but unfortunately this is not always possible. Modern restaurants are infamous for sneaking MSG into everything, and deceptive labeling can make it almost impossible to correctly identify it on food labels. Additionally, some people are so sensitive to glutamate that even the low quantities naturally occurring in otherwise healthy foods, like tomatoes and mushrooms, can trigger symptoms. And yet, the fact that many people can seemingly consume MSG with impunity, free of at least any short term effects, suggests that the exquisite sensitivity of certain individuals may be the effect of some other underlying cause. If such a cause could be found and addressed, it would be possible for even the most sensitive individual to reduce the unpleasant effects occasioned by its accidental consumption or relax the often socially crippling constraint of needing to avoid it entirely. While everyone is assuredly better off minimizing their consumption of added MSG, avoiding it entirely is not always possible, so the following supplements may help to counteract its effects in sensitive individuals:
- N-Acetyl Cysteine: a sulfur-containing amino acid, in neurons cysteine and glutamate operate a membrane antiporter system. Basically, whenever neurons release excitatory glutamate, they simultaneously take up cysteine. This leads to increased glutathione production in the cell, protecting the excited neuron from subsequent free radical generation. One of the potential dangers of added MSG is the resulting imbalance it creates in the extracellular levels of glutamate and cysteine. The mechanism of MSG’s excitotoxicity may involve excess free glutamate in the synapse decreasing the neuron’s ability to make glutathione, leaving it that much more vulnerable to oxidative damage.
- L-Carnitine: another sulfur-containing amino acid, carnitine has been shown in-vitro to protect neurons from both ammonia- and glutamate-induced toxicity,[ii] making it an obvious choice to guard against the dangers of MSG. The precise mechanism is unknown, but carnitine seems to exert its protective effects by modifying the activity of cellular glutamate receptors.
- Taurine: glutamate and taurine are the two most abundant signaling amino acids in the brain. They exert opposite effects, with taurine basically closing the calcium channels that glutamate floods open. Low taurine levels can potentiate glutamate’s toxicity, especially in the heart, so taurine may be especially helpful for controlling MSG-induced cardiac symptoms, like dizziness and heart palpitations.
- Vitamin B6: the body eliminates excess glutamate in the nervous system by converting it to GABA, a reaction which requires vitamin B6 as a cofactor. Radiating numbness was one of the original symptoms of Chinese Restaurant Syndrome, and the rapid consumption of B6 in the nervous system might explain this phenomenon since B6 deficiency is known to cause neuropathies. It is possible that a borderline B6 deficiency or genetic polymorphisms in B6 metabolism might explain why some people get symptoms from eating MSG and others do not.
Even if it could be shown that MSG is not directly toxic, its widespread addition to processed foods has caused many indirect problems. For instance, excess free glutamate exaggerates the insulin response to foods, dramatically lowering blood sugar and leading to instantly renewed hunger. This, combined with MSG’s potentially addictive interactions with GABA in the brain, creates such a recipe for overeating that one wonders if the food industry is not doing this on purpose to sell more food, ruthlessly contributing without qualm to the obesity epidemic. Even more pernicious than MSG’s effect on the quantity of our food consumption is its terrible effect on the quality. The tongue was designed by nature to tell us what foods are best to eat because the foods naturally highest in glutamate also tend to be the highest in protein and most nutritious generally. Naturally occurring free glutamate essentially acts as a nutrient bellwether, which means adding glutamate to snack foods made from cornmeal, sauces and gravies made from cornstarch, noodles made from flour and water, soups that are mostly water and vegetables with very little meat–in other words, foods which basically amount to the gruel and potage consumed by impoverished peasants in the Middle Ages–tricks the brain into thinking these low-quality foods are actually nutritious. No person would ever voluntarily subsist on gruel, as its blandness automatically compels one to seek out a much broader variety of more nutrient-dense alternatives. But when cornmeal fried in the oil of a processed seed, which would otherwise be inedible to humans, can be made to taste more delicious than anything which has ever been found in nature, the result is what has been coined the “Dorito Effect,” a new form of malnutrition at least as harmful as any of the diseases rightly or wrongly attributed to MSG.
[i] Minoru Kouzuki, Miyako Taniguchi, Tetsuya Suzuki, Masaya Nagano, Syouta Nakamura, Yuto Katsumata, Hideki Matsumoto, Katsuya Urakami. Effect of monosodium l-glutamate (umami substance) on cognitive function in people with dementia. European Journal of Clinical Nutrition. 2019; 73: 266-75.
Any homeopathic claims are based on traditional homeopathic practice, not accepted medical evidence. Not FDA evaluated.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.