Monosodium glutamate (MSG) has been a staple ingredient in Asian cooking since it became commercially available in the 20th century. It is now a convenient flavour booster for many foods.
But there are plenty of restaurants that declare their dishes are MSG-free, and chefs who proclaim that their food is enhanced only with natural ingredients. But for every person against the use of the food enhancer, there’s another who champions it wholeheartedly.
Eating with the enemy?
While it has its uses, eg, making bland diets more appealing to children, the elderly and the sick, the judicious use of MSG is still important.
The Nutrition Research and Development Division of the Department of Science and Technology, Philippines, conducted a study on 67 healthy seniors from a home for the aged. It reported increased food intake with MSG compared to just seasoning with salt, with no adverse hypertensive effect. Nevertheless, it still advises the moderate use of flavour enhancers for the elderly.
Another study, conducted by the University of the Philippines-Philippine General Hospital, noted how MSG can encourage diabetics to consume food items with a low glycaemic index, but points out that increasing the recommended amount of MSG in a dish may actually lead to decreased palatability – hence the necessity of a light hand when using the seasoning.
“I agree [with the studies, but] of course, moderate intake is a must,” says nutritionist and dietician Felicidad Velandria. MSG is 30% sodium and 70% chloride, while table salt is 40% sodium and 60% chloride, she says.
Of mice and MSG
Studies have also been conducted on guanylate, a substance much like glutamate, and its effects on the digestive system. Beyond tongue perception, humans also detect guanylate as it is absorbed via the stomach or intestines.
In a paper published recently in The Journal of Neuroscience, genetically-mutated mice deprived of the ability to taste umami, the fifth taste that food enhancers add, still gravitated to water flavoured with MSG compared with plain water – showing a post-ingestive appreciation that human beings also have for the protein.
Humans are innately wired to like glutamate, from the first exposure in the womb, where it is present in amniotic fluid, as well as in human breast milk, where its concentration exceeds that in cow’s milk by 10 times. Glutamate and other umami triggers like inosinate and guanylate occur naturally and can be found in many savoury dishes, eg, miso soup, steaks and pizzas that feature tomatoes and cheese. It is also found in patis, soy sauce and Worcestershire sauce. That dashi broth flavoured with seaweed and bonito flakes that you see in episodes of Iron Chef? That’s the fusion of inosinate and guanylate in a stockpot.
Many studies have debunked MSG’s alleged harmful properties by attributing allergies, headaches or other symptoms to other factors involved in eating food items seasoned with it. It is interesting to note that a report commissioned in 1995 by the US Food and Drug Administration and performed by the Federation of Societies for Experimental Biology (FASEB) found no proof to link the adverse claims of anti-MSG proponents – but acknowledged reports that asthmatics may be more sensitive to MSG than the general population.
The FASEB study also claimed the possibility of 1% of the test population exhibiting MSG symptom complex, popularly known as Chinese restaurant syndrome, after they were fed an oral dose of 3 g in the absence of food. Other studies have pointed out a link between MSG sensitivity and vitamin B6 deficiency.
Whether one is truly deficient in vitamin B6, asthmatic, or just a hypochondriac – ‘better safe than sorry’ seems to be the approach in choosing food items without MSG.
As a flavour enhancer, MSG does the job in giving dishes more oomph. Its creation from naturally umami-producing sources does not make it an artificial ingredient, claim its manufacturers. Nevertheless, if a meal to begin with is deficient in vitamins or nutrients, or does not provide the necessary calories, the human body’s response is to seek more calories. People consume calories to both satiate hunger and fulfil the desire for a delicious meal. But if our meals do not adequately meet what our body needs, we may unwittingly consume more than we require, leading to lifestyle diseases like obesity.
As an aid to make dishes tastier, MSG can help people eat nutritionally-rich, but bland, food items. Some may argue that dishes can already be improved with patis, soya sauce, Worcestershire sauce, or the use of ingredients like shiitake mushrooms, red tomatoes, Parmesan cheese or bonito flakes –hence, why use MSG at all?
Convenience lies at the heart of its creation. It doesn’t quite end world hunger, but try arguing about that when you raid the kitchen pantry at midnight for instant noodle.