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Episode 4: MSG The Nugent Report
The Nugent Report the science behind health and nutrition. Welcome to this episode of The Nugent Report, a definitive source for objective information on health and nutrition. Featuring Dr. Steve Nugent, the renowned psychologist, author, public speaker and expert on science, health, wellness and nutrition. Be sure to visit our website at ‘drnugen.com’ and follow us on Facebook, twitter and Instagram @TheNugentReport.
Steve Nugent: Hello and welcome to another episode of The Nugent Report. On this Nugent Report, we’re going to be talking about MSG (Monosodium Glutamate). A poll was taken on The Nugent Report Facebook page and the majority of the respondents said, they wanted to hear a podcast or see a blog on MSG. Well, I wasn’t really planning on this, but this is what my subscribers wanted so, so be it. If you’re sensitive to MSG or at least you believe you are, then you already have a good idea of what it is but not everyone does. So, let’s start by explaining what MSG is.
MSG is an abbreviation for Monosodium Glutamate and it’s commonly used as a flavor enhancer in many foods. From Bouillon cubes to canned vegetables. Believe it or not, MSG was first isolated by a Japanese scientist back in 1908. He was researching a particular flavor which is found in a seaweed an edible seaweed, which is called Kombu. And he was successful in his effort. So, it’s been around for a long time. Chemically, it’s a sodium salt of glutamic acid. Glutamic acid is a non-essential amino acid and that means it occurs naturally in the body. It’s required for building proteins in your body. It’s found in many different types of animal and plant proteins.
It also is a neurotransmitter, so that makes it pretty important and it’s required for ammonia metabolism. So, please understand that glutamic acid is not MSG. I get that question a lot. So, they’re not the same thing. So, MSG is a sodium salt of glutamic acid. The US FDA says that, MSG is safe but some disagree. Some have even implied that MSG could lead to brain damage. I must point out that there is no peer-reviewed science literature to support that. Remember that The Nugent Report is dedicated to bringing you objective science. That means you’re going to get both sides of this story.
The people who report various symptoms associated with MSG are often said to have Chinese Restaurant Syndrome or CRS. Because it’s most commonly used in Chinese food. The first paper on Chinese Restaurant Syndrome was actually published in the new England Journal of Medicine back in 1968 and the author was RH Quok. In his paper, he reported that after consumption of Chinese food, there was some reports of what he called Transient Subjective Symptoms. Which included some of the classic symptoms discussed in this episode.
To report this episode to you, I looked at quite a number of individual studies and they all unfortunately were reporting inconsistent results. So, that took me to the next step and that was to look at systematic review papers of the individual papers. So, the question that comes up is. Is MSG actually bad for you? According to the FDA and numerous scientific studies, it isn’t. however, there are people who consume food or liquids with MSG and report a number of different unpleasant symptoms. Including headache, flushing, nausea, chest pain, sweating, general weakness, pressure or tightness in facial muscles. As well as numbness, tingling and even burning sensations in the neck or the face.
Some people also report heart palpitations. Could all these people be wrong and the government be right? Is this a simple yes or no answer? Well, the Food & Drug Administration classifies MSG as gras. So, that’s an abbreviation. So, GRAS in capital letters and it means generally regarded as safe. MSG is not only used in Chinese food; it’s also used to enhance the flavor of soups and canned vegetables and canned meats and other things. It’s not just the FDA that says that MSG is safe, joint expert committees from the Food & Agricultural Organization of the united nations otherwise known as the FAO. And the expert committee on food additives of the World Health Organization otherwise known as the WHO or WHO.
They conducted studies on MSG in 1971, 74 and then again in 1987. They determined what they called an ADI or Accepted Daily Intake. And they concluded that the use of MSG did not present a health hazard. How can so many people have such a wide range of symptoms while the government says that MSG is safe? To answer a question like that, would require an exhaustive scientific study and that simply isn’t possible for me to either finance or conduct at this time. So, the most logical approach is to look into peer-reviewed science journals to find what’s called a meta-analysis or a systematic review paper.
Essentially a meta-analysis or a systematic review is simply kind of a study of a bunch of studies. Scientists conducting analyses of these type will study two or more studies to give a better consensus in most cases than simply looking at one study alone. This is definitely necessary when the question is about MSG. This type of analysis was conducted in 2016 by two researchers, named Obayashi and Nakamura. Their study was specifically designed to find out if there was a causal relationship with headaches reported by people using foods containing MSG. And if there was any scientific literature to support it.
These two scientists pointed out that MSG is classified as a causative agent of headache in the international classification of headache disorders third edition. The available scientific literature however gives us mixed messages. That’s what led me to look at a systematic review of a very large group of papers. Obayashi and Nakamura conducted this type of review on human studies, which included the incidence of headache after an oral administration of MSG. An analysis was made by separating human studies with MSG administration with or without food. This was done because different journals have reported inconsistent results based on the use of MSG in food or MSG in liquids.
MSG as an example is commonly used in Bouillon cubes and in soups. One of several individual studies that I looked at in preparation for this episode was by two scientists named Tarasoff and Kelly. This was a double-blind placebo control that was published in a peer-reviewed journal called Food & Chemical Toxicology back in 1993. Tarasoff and Kelly pointed out that conducting a blinded study was extremely difficult, because the taste of MSG was distinctive. And therefore, the placebo would be obvious to most test subjects versus a food or a liquid containing the MSG.
The idea of a double-blind placebo control study is that, no one in the study knows who’s taking the placebo and who’s taking the active agent. There have been other problems reported on individual studies to arrive at firm conclusions, this is not the only one. Once again this is why I looked at an exhaustive systematic review paper of a wide variety of studies. Tarasoff and Kelly reported that only 14% of the human test subjects in their study responded to the placebo and 15% responded to MSG. On the surface, this would suggest that there are almost as many people imagining that they’re having an effect as those who are actually reporting an effect from the MSG itself. So, this wasn’t very helpful.
Obayashi and Nakamura reviewed studies done on a very wide range of circumstances with various levels of dose administration of MSG. Some far above what you would normally get in food and in a variety of different foods and liquids. The results from one study to another were pretty inconsistent. Although, there was a suggestion that there might possibly be more significant effect on some females than males. Again, not conclusive. They acknowledge that doing a double blind with liquids was pretty difficult, in fact pretty close to impossible. Because you can taste the MSG and the liquids distinctly
After analyzing all of the data together their conclusion was that, there was no causal relationship that could be established between the intake of MSG and headaches. Now that’s after reviewing a very wide number of studies under a really broad scope of circumstances. Headaches are of course only one symptom that are reported by people who seem to be sensitive to MSG. So, it’s clear to see why government agencies tell us that MSG is safe. They’re going on the available science that’s been published. In science, you have those things which are proven, those things which are disproven and those things that require further study.
In the case of MSG, clearly further study is required. I have seen many people in my career who I believe sincerely are suffering the effects of MSG. But without the science to substantiate it, we can’t draw the conclusions that many people are looking for at this point. So, just because the study hasn’t been shown yet to validate a causal connection between these unpleasant symptoms and the MSG, that doesn’t mean they’re not real. I believe they are.
So. if you consume a food or a food additive and have any symptoms that are less than pleasant or positive. The prudent thing to do is to avoid that food or food additive in the future. I wish that for the purpose of this episode, I could give you absolute conclusions. But unfortunately, the science isn’t there yet. So, that’s it for this episode of The Nugent Report. Remember be safe, be sensible and stay objective.
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《纽金特报告（The Nugent Report）》第4集：谷氨酸钠
《纽金特报告》，阐述健康与营养背后的科学。欢迎收听本集《纽金特报告》。《纽金特报告》是有关健康和营养客观信息的权威来源。由著名心理学家、作家、公共演说家、科学、健康、保健和营养方面的专家史蒂夫纽金特（Steve Nugent）博士主讲。我们的网站是“drnugent.com”，你可以在脸书（Facebook）、推特（Twitter）和Instagram @TheNugentReport上关注我们。