Monosodium glutamate (D-glutamic acid, MSG) is a man-made substance with a mixed reputation. Some think it is evil; some scientists say it is not. I won’t weigh in that particular hornet’s nest. I do have a lot to say about natural glutamates.
L-glutamic acid, and its ions and salts glutamate and glutamine, are present in many whole foods. These compounds can be found in every human cell. Glutamates are naturally occurring compounds and a source of savory or umami flavors. Seaweed, particularly kelp and konbu, is naturally high in glutamates(1). Much as the phytic acid in legumes may cause gastrointestinal upset for some but not others, some people may have extreme sensitivities to glutamate. If you are sensitive to MSG, this does not necessarily mean you will automatically be sensitive to glutamates(2). Let’s examine glutamate in the context of bone broth.
Many people who want to make and consume greater amounts of bone broth are doing so to because they are following a whole foods diet, are trying to heal a leaky gut or other autoimmune issues, or perhaps just because they really love soup. There are a few different perspectives on natural glutamates (including glutamine, glutamic acid, and L-glutamic acid) to consider.
In particular, the Gut and Psychology Syndrome (GAPS) diet initially restricts bone broth that has higher amounts of glutamine. If you are following the GAPS diet on the advice of a medical practitioner, you will likely begin your broth journey with a shorter-simmered meat stock. If you are not following the GAPS protocol, the following may be of no concern to you. There are many ways to heal a leaky gut. Your healthcare practitioner, as always, should be your first port of call in making important health decisions.
Long-simmered bone broths develop deeper savory flavors, and as many foods such as high-quality turkey and salmon do, more natural glutamates are created by heat-based cooking(3). In fact, glutamates are in nearly every food we eat. We're built to eat it: our tongues have specific receptors for glutamates(4). The Healthy Home Economist published an article about health concerns with naturally occurring glutamates. A related article provides an actual lab analysis of proteins in short vs. long-simmered bone broths. Short-cooked stock is listed as having 366 mg of glutamic acid. Long-cooked broth has 1013 mg. Long-cooked broth has about three times the amount of glutamic acid as short-cooked broth. I have no concerns about the reliability of the data; it was analyzed by a respect laboratory.
However, there is no context given for the data, and that does concern me. The numbers do not paint the entire nutritional picture of glutamic acid and glutamates. While one option may be three times higher in glutamic acid, the information we’re missing is: how much natural glutamic acid is harmful?
Glutamic acid in its amino acid form, glutamine, is one of the most important amino acids in the human body. Without it, neurons fire more slowly; the small intestine functions less efficiently. It is the brain's primary 'food' and one of the primary neurotransmitter. Our bodies make it naturally(5).
Glutamates naturally occur in breast milk. The most abundant amino acid in breast milk has 0.02% of glutamate, so a 5kg baby who takes 800 ml of breast milk a day, consumes 0.16g of glutamate(6). It’s in most of the foods we eat: one roasted chicken breast has 8620 mg of glutamic acid; a serving of sunflower seeds has 1210 mg; salmon has 1294 mg. Gelatin, the desirable goal of making any kind of broth or stock, itself contains 10% glutamic acid by weight(7).
Glutamates naturally occur in breast milk. The most abundant amino acid in breast milk has 0.02% of glutamate, so a 5kg baby who takes 800 ml of breast milk a day, consumes 0.16g of glutamate(6). It’s in most of the foods we eat: one roasted chicken breast has 8620 mg of glutamic acid; a serving of sunflower seeds has 1210 mg; salmon has 1294 mg. Gelatin, the desirable goal of making any kind of broth or stock, itself contains 10% glutamic acid by weight(7).
Is it relevant to you whether your bone broth has more or fewer glutamates? That’s a question for your healthcare practitioner. If you decide to avoid long-simmered broth because of the glutamic acid levels, you may wish to evaluate the rest of your diet for other problematic foods that also contain this compound.
There are some medical conditions where glutamic acid is beneficial and others where it is bad. Some immune conditions are helped by glutamine, and some patients need to take glutamic acid supplements. Other patients, such as those with very specific types of brain cancers, are cautioned away from glutamic acid(8). This does not mean that glutamic acid causes brain tumors. If it did, every living human being would have one because we are full of glutamates!
Remember, we are literally made of glutamates. Of the 20 amino acids needed for protein synthesis, glutamine is the most abundant, making up 50% of all amino acids in the blood and 60% of those in the body(9). For some people, glutamic acid might be an anti-nutrient that works against you – much like phytic acid, the anti-nutrient we reduce when we soak beans and nuts to avoid stomach upset. Does phytic acid cause cancer? No. In fact, phytic acid may protect us from cancer, even as we might tolerate it well or not. But if you are very sensitive to it, then do what you can to avoid it.
Remember, we are literally made of glutamates. Of the 20 amino acids needed for protein synthesis, glutamine is the most abundant, making up 50% of all amino acids in the blood and 60% of those in the body(9). For some people, glutamic acid might be an anti-nutrient that works against you – much like phytic acid, the anti-nutrient we reduce when we soak beans and nuts to avoid stomach upset. Does phytic acid cause cancer? No. In fact, phytic acid may protect us from cancer, even as we might tolerate it well or not. But if you are very sensitive to it, then do what you can to avoid it.
Is glutamic acid, glutamine, or glutamate harmful for us to consume? If you Google this question, you may wish to reschedule the next few weeks to evaluate the thousands of articles that reference these compounds. On this question, follow the advice of a healthcare practitioner who knows your specific medical history. For the majority of people, if you are able to drink broth and not experience stomach upset, headaches, or increased blood pressure, you can do so if you enjoy it and if you feel healthier when you consume it. If you have issues, or a malignant brain tumor, that's when you need to consult a healthcare practitioner. That includes helpful resources such as nutritionists, naturopaths, and other skilled and food knowledgeable professionals.
It’s easy to get overwhelmed with all of the conflicting information on the interwebs and in books. Many of us have participated in discussions where you think you have a handle on everything, until someone comes along and tells you that you are doing absolutely everything wrong. Those moments are difficult and frustrating to say the least.
If you are consuming bone broth but are not getting the health results you wish, it’s time to seek more healthcare advice. Certainly do not take medical advice from a bone broth addict and blogger like me. I only encourage you to look at all the facts, make informed decisions, and lean on a good healthcare professional as needed for guidance.
Most importantly, remember that the Internet and its many strangers should never, ever be a substitute for real medical advice from someone who knows you and your medical history.
(1)http://www.fda.gov/Food/IngredientsPackagingLabeling/FoodAdditivesIngredients/ucm328728.htm
(2)Harold McGee, Lucky Peach [Quarterly food and writing magazine], Summer 2011.
(3)Harold McGee, On Food and Cooking.
(4)Biol Pharm Bull. 2008 Oct;31(10):1833-7. Multiple receptor systems for glutamate detection in the taste organ. Yasuo T1, Kusuhara Y, Yasumatsu K, Ninomiya Y.
(5)http://www.npr.org/2012/10/16/163002343/test-kitchen-chefs-talk-the-science-of-savory
(6)Am J Clin Nutr, September 2009, vol. 90 no. 3, 719S-722S
(7)Stevens, P.V. (1992). "Unknown". Food Australia 44 (7): 320–324.
(8)Epilepsy Res. 2012 Jul;100(3):310-26. doi: 10.1016/j.eplepsyres.2011.06.017. Epub 2011 Aug 31.
(9)Ziegler TR, Benfell K, Smith RJ, et al. Safety and metabolic effects of L-glutamine administration in humans. JPEN J Parenter Enteral Nutr. 1990 Jul;14(4 Suppl):137S-46S.
