Almost a century after its discovery and patenting a process for manufacture of Mono Sodium Glutamate popularly known as MSG, the controversy regarding its safety is still being debated though it is used extensively by the food industry as a flavor enhancer. It has an E number 621 which signifies that it is safe for human consumption, though compulsory labeling is mandated. In many countries there is no upper limit restriction for its use in any food. Oriental countries like Japan and China are the pioneers in this field with practically every food they consume containing MSG. Though it was made till some years ago using wheat gluten as the raw material by hydrolysis, emergence of gluten allergy amongst many people led to the development of alternate technology based on fermentation using starch as substrate.
Recognition of the fifth basic taste Umami as a new one besides the traditional salty, sweet, sourness and bitter tastes, owes its origin to MSG and the bound glutamate in products like tomato, cheese and cured ham are supposed to represent purest form of Umami taste. Added to this, specific receptors for Umami have been identified on human tongue confirming the existence of this fifth taste category. Ajinomoto Company is considered the pioneer in commercial manufacture and promotion of MSG globally and with an annual business turn over of more than $ 13 billion, it is a leading player in areas like food ingredients, pharmaceuticals, beverages, amino acids, specialty chemicals with operations in 122 countries. Naturally with such massive spread, clout and economic muscle Ajinomoto has been able to ride the storm caused by uncertainties regarding the safety of MSG.
More than 80% of the annual production estimated at 2.2 million tons is consumed in Asia with mainland China guzzling a whopping 1.2 million tons working out to 1.2 kg per capita consumption per year. Added at 0.1 to 0.8% to different foods, the main objective is to enhance the flavor of the final food preparation. While many consider MSG as one of the exitotoxins affecting brain functions, other critics point an accusing finger at MSG for a variety of reactions after consumption that include neurological problems, cancer, fibromyalgia, depression, obesity etc none of which has been supported by any scientific evidence. For fear of adverse effect on brain functions, MSG is not generally permitted in foods targeted at children below the age of 3 years because of their underdeveloped but growing brain. This situation is similar to the present state of HFCS which, though a natural constituent of sucrose, is being blamed by many as responsible for creating the obesity epidemic through foods rich in this sugar with not much scientific evidence to support such a theory.
It is against this context that the recent reported alliance between the US Department of Agriculture's Agricultural Research Service (ARS) and Ajinomoto Company for taking up a joint R & D project to explore whether, this chemical used to enhance the taste of foods, has any beneficial effects on eating behavior and body weight management. According to the their agreed program trials are to be conducted by ARS' Western Human Nutrition Research Center (WHNRC) to assess in overweight women whether adding sodium glutamate to foods can facilitate a better control of appetite and caloric intake, and prevent body weight rebound following a period of moderate energy restriction and weight loss. This is based on the surmise that for many people, long term improvements in eating behavior and body weight control are difficult to maintain calling for an in-depth study on the mechanisms involved in such cases. The study team believes that MSG inclusion in regular diet can improve the quality and quantity of food consumed while at the same time providing "emotional and pleasurable" factors resulting in lesser motivation for consumption of calorie dense foods.
Though the alliance between the government agency and Ajinomoto with vast business interest in MSG may be controversial, the step may be in right direction as long as the industry partner in this study does not throw its weight around in influencing the study in any way favoring its interests. The ability of MSG in reducing sodium intake from savory foods is another interesting line of pursuit as there are some studies reporting 20% to 40% reduction in salt requirement to achieve acceptable taste when MSG was present in formulated food products at low concentrations. Probably while pursuing these studies in collaboration with Ajinomoto, USDA should keep in mind the concerns of a significant segment of the consumer population regarding the safety of MSG in general.