From the Vaults – The Science of MSG

Editors note: To welcome any readers that may be coming to my blog from my recent post regarding GMOs on LIVESTRONG.COM, I’m reposting one of my earlier discussions about another misunderstood topic in food: monosodium glutamate, or MSG.

As discussed in last week’s article, some creative scientists are examining the changes in Hawaiian seafood menus over time for useful data about fishery abundance. If researchers were to study another set of menus, those of Chinese restaurants in the United States, they would find a similarly interesting trend: from the early 1970s onward, many menus began to advertise the absence of monosodium glutamate, or MSG, in their cuisine. The U.S. Food and Drug Administration, however, has labeled MSG as a “generally recognized as safe” food ingredient since 1959. A sudden change in public perception led to these changes, but the roots of that perception are surprisingly obscure.

Courtesy of closter1chinesefood.com

Although MSG was only formally discovered in the early 20th century by Japanese chemist Kikunae Ikeda, the compound from which it is derived, glutamic acid, is one of the 20 amino acids necessary for proteins (and therefore life itself). The body recognizes the importance of glutamic acid through the sense of taste in foods like asparagus, tomatoes, cheese and meat. Just as the tongue’s taste buds detect sodium chloride as salty, sucrose as sweet, or quinine as bitter, they register glutamic acid as its own unique taste, designated by Ikeda as “umami,” a Japanese word for “delicious” or “yummy” that is often translated as “savory.” MSG is simply glutamic acid that has been stabilized through the addition of sodium; for comparison, MSG contains one-third the amount of sodium per unit volume as table salt.

Asian cooking traditionally derived umami flavor from ingredients such as seaweed (from which Ikeda first isolated glutamic acid) and dried tuna, but by the 1950s, purified MSG was available to the United States as the seasoning Ac’cent. Restauranteurs and food processors were quick to adopt the ingredient as an inexpensive way to bolster the flavor of their products. No concerns were raised by the substance’s inclusion until 1968, when a Chinese-American doctor named Robert Ho Man Kwok reported feeling a number of ill effects after eating at Chinese restaurants in the United States.

As BuzzFeed’s John Mahoney outlines, Dr. Kwok hypothesized in the New England Journal of Medicine that his symptoms may have been “caused by the monosodium glutamate seasoning used to a great extent for seasoning in Chinese restaurants,” and after the New York Times covered the story, a flurry of experiments were conducted to confirm his suspicions. Many of these studies did report an association between high doses of MSG and symptoms such as headaches and flushing, but they lacked the proper scientific rigor of double-blind design (in which both the experimenter and subject do not know which treatment is being administered) or placebo controls.

Better designed experiments over the following decades failed to confirm the results of earlier research, and a comprehensive review by the Federation of American Societies for Experimental Biology concluded that were was no association between MSG and short- or long-term health issues in humans. Despite this research, a number of groups have continued to advocate about the perceived dangers of the compound, and MSG has been absent from baby food since 1969. Yet as the scientific consensus stands, one should feel no fear in enjoying a plate of egg foo young from a Chinese restaurant, even if the menu is silent about the presence of MSG.

From the Vaults: A Wooly Issue – Deextinction of Mammoths

Editor’s note: Thanks to you, the readership of Sword of Science has significantly increased from my first posts nearly a year ago. I recently started volunteering at the Cincinnati Museum Center, and in honor of their emblematic Ice Age Trail, I’m reposting one of my earliest pieces, about efforts to bring back extinct species such as the woolly mammoth.

A little less than a week ago, a team of Russian scientists announced a startling find in the frozen wastes of Siberia: the complete carcass of a woolly mammoth, a relic from the most recent ice age over 10,000 years old. Although mammoths have been unearthed from the permafrost before, they are rarely recovered in such pristine condition, and never have they been found with liquid blood. Of course, there are only two words that come to mind when the blood of extinct species is mentioned: “Jurassic Park.”  The central conceit of Michael Crichton’s novel is that dinosaur DNA from blood trapped in amber-preserved mosquitoes is used to resurrect the Mesozoic beasts, with dire consequences.

While it’s unlikely that a herd of woolly mammoths will go rampaging through an ice age theme park anytime soon, it is becoming increasingly feasible that the genetic resources necessary to clone a mammoth will be developed. Blood itself is actually a rather poor medium from which to extract ancient DNA: red blood cells, or erythrocytes, do not contain any genetic information, and white blood cells, or leukocytes, are fairly fragile. In the words of Stephen Schuster, the biologist behind the sequencing of the mammoth genome, the genetic material in the mammoth blood is probably “as shattered as if you took a mirror and threw it on the floor.” Research is already in progress to clone a mammoth from bone marrow cells, which are more resilient and have better-preserved DNA.

A frozen baby mammoth, courtesy of National Geographic

Considerable amounts of effort are being invested in this project, but why (or is it even) a worthwhile investment? The “wow” factor of bringing back an extinct species is certainly a large part of the rationale. The sense of reaching back into the past, of letting people see something that hasn’t been seen for millenia, excites the imagination and draws attention to science in general. Conservation biology has a similar concept in the “flagship species,” a charismatic large animal that serves as a focus for  the ecological concerns of the general public. The plight of the manatee, for example, draws in attention and funding for the preservation of the Florida Everglades. Bringing back a mammoth would encourage a new generation of young scientists to explore the fields of molecular biology and paleontology. This kind of project may also put a more favorable public light on genetic technology, which has recently received a lot of negative attention due to the fight over GMO labeling and a recent Supreme Court case involving the agribusiness giant Monsanto.

Some scientists, like Jose Folch, see a bioethical imperative for work on de-extinction. Folch, whose team successfully cloned the extinct Pyrenean ibex (albeit one with a lifespan of seven minutes), believes that his work may serve as a basis “for future cloning-based conservation.” There is a sort of inherent justice in the thought that species wiped out by direct human impacts, like the passenger pigeon and the Steller’s sea cow, might one day be restored by direct human effort. However, there are many steps remaining between cloning an individual and reestablishing a population of an extinct species. Clones are genetically identical, and therefore rather vulnerable to disease or ecological stresses. Evolution and migration have shaped ecosystems in the absence of extinct species, even over the short timespans some have been extinct, and it is likely that not all species would fit comfortably back into their niches. A less obvious danger is the thought that with this sort of technology, the importance of traditional conservation is somehow reduced. Why bother with protecting existing species if we can call them back at will? Yet as scientists have continually learned, all species are connected; the loss of one obvious organism could have unforeseen effects on countless others, and it’s best to conserve as many as possible while we try to understand the web of life.