Psychology Department

Health Psychology Home Page

Papers written by students providing scientific reviews of topics related to health and well being

  HomeWeight LossAlternative Therapy | Supplements | Eating Disorders | Fitness | Links | Self-Assessment | About this Page |


The Fifth Taste: Is It Worth The Risks?

Cayla Conway

September 24, 2007



Many of us have seen the “No MSG upon Request” notice at the bottom of our menus at our local Asian restaurant.  Although some of us make this request, many of us do not.  If you knew that MSG could possibly put you at risk for obesity, would you think twice next time you ordered food prepared with MSG?




            Monosodium glutamate (MSG) is a sodium salt of glutamic acid, an amino acid which is found in all protein.  The flavor enhancing abilities of MSG were discovered in 1908 by Professor Kikunae Ikeda of Tokyo Imperial University.  Ikeda isolated the principal taste component of Japanese soup bases made from a type of seaweed.  After many chemical experiments, C5H9NO4 or glutamic acid was extracted. 

Ikeda described MSG as: “a taste which is common to asparagus, tomatoes, cheese and meat but which is not one of the four well-known tastes of sweet, sour, bitter and salty.” Ikeda named the taste and scientifically accepted term, umami, after the Japanese word umai meaning “savory” or “deliciousness.”  Umami is often considered the fifth taste. (  





Why all the fuss about MSG?

Many people think that MSG is only something found in Asian cuisine, however, free glutamic acid can be found in many foods: canned soups, frozen dinners, potato chips, and cookies, to name a few. MSG is a chemical that is found in a number of foods naturally (such as tomatoes and cheese) as well as an additive in many foods, thus, it is important to understand the effects it may have on our health.  (


“The Taste that Kills”

Extensive studies have been done on the particular relationship between MSG and obesity.  In Dani Varacity’s article, “The Link between MSG in Processed Foods & Obesity,” summarizes the results of animal studies performed by Dr. Russell L. Blaylock.  In his book, “Excitotoxins – the Taste that Kills,” Dr. Blaylock classifies MSG is an excitotoxin, a chemical that can overexcite neurons and cause cell damage.  The results of Dr. Blaylock’s studies show that excess MSG created a lesion in the hypothalamus and lead to abnormal development and problems, such as obesity, in the subjects. Veracity states that, “By avoiding foods with MSG, you are not only protecting your health and your family's health, you are also protecting society’s health […].” (




            Another research report, “Obesity, voracity, and short stature: the impact of glutamate on the regulation of appetite,” focused on the correlation between MSG and obesity by administering MSG during pregnancy and early development of rat pups.  Some of the pregnant rats were administered 2.5 g of MSG orally, another group was administered 5 g MSG, and the last group did not receive any MSG.  After the pups were weaned, MSG was administered directly to the pups respectively.

            The conclusion of the research was that increased administration of MSG during both pregnancy and development increases appetite in rats.  The animals fed 5 g MSG per day increased water uptake by threefold and food uptake by almost two-fold. Also, the influence of MSG was, in general, more prominent in males than in females.  Similar to the previous study, the results were attributed to affect of MSG on hypothalamic control.  High doses of MSG tripled the amount of insulin in the pancreas of the rats, which could also be a contributing factor to increased appetite and obesity in the test subjects.  (



MSG: Under More Scrutiny

            Other studies have been conducted to test the adverse effects of MSG and its relation to other medical problems.  The Chinese Restaurant Syndrome, also called monosodium glutamate symptom complex, includes symptoms such as sweating, headache, and flushing that some people experience after eating MSG-rich food.  Although there is no proven correlation between MSG and the Chinese Restaurant Syndrome, MSG is often the culprit used to explain these symptoms.  (

            It is also suspected that MSG might have an addictive property.  Glutamate and GABA (gamma-aminobutryic acid) are both neurotransmitters that control the brains level of excitation.  Similar to many addictive drugs, MSG affects GABA to cause stimulating effects on the brain.  An addiction to this sensation would create a desire for anything containing MSG.  It is obvious to see how this would increase the risk of obesity. (

There are also various hypotheses and studies concerning the correlation between MSG and Diabetes, Asthma, Hypertension, and the list goes on.  It is because of this controversy that the FDA requires MSG to be listed on all ingredient lists of foods containing the additive.



With the obesity epidemic on the rise, it is important to consider any possible contributing factors.  Although the Food and Drug administration declared MSG as a “generally recognized as safe” food ingredient under the Federal Food, Drug, and Cosmetic Act in 1959, there are still studies being conducted about the possible adverse effects of the additive. ( Although the research mentioned above has yet to be conducted on humans, it is important to keep the results of these experiments and the potential risk that MSG may pose to your health in mind the next time you desire food containing MSG.




Works Cited:


Du Plessis, Karen. (2004). A Case Study. Allergen Advisor Digest.


Hermanussen, M., & Treguerres JAF. (2005, Aug 31) Obesity, Voracity, and Short

Stature: the Impact of Glutamate on the Regulation of Appetite. European Journal of Clinical Nutrition. 60, 25-31.


Meadows, Michelle. (2003, Jan). MSG: A Common Flavor Enhancer. FDA Consumer



Veracity, Dani. (2005, July 9). The Link between Monosodium Glutamate (MSG) and Obesity.



Clip art from Google Image Search


Psychology Department

The Health Psychology Home Page is produced and maintained by David Schlundt, PhD.

Vanderbilt Homepage | Introduction to Vanderbilt | Admissions | Colleges & Schools | Research Centers | News & Media Information | People at Vanderbilt | Libraries |Vanderbilt Register | Medical Center 

  Return to the Health Psychology Home Page
  Send E-mail comments or questions to Dr. Schlundt