What About MSG?

Have you ever thought "what is the deal with MSG?" Many of my patients, colleagues and even I try choose foods without MSG, but do you know why you're avoiding it and what it is? If you're a curious soul like me, read on to get some facts about MSG.

Monosodium glutamate is a salt formed from the amino acid glutamate, sodium, and water. It originally was extracted from seaweed kelp by Japanese chemist Ikeda Kikunae.  It is used in our food industry to enhance natural flavors and is often found in soups, crackers, potato chips, casseroles, meat, seafood, prepared pastas, Chinese food, broths, spices/ seasonings, gravy and sauce mixes. Glutamate is used in our bodies to make protein and also naturally occurs in dairy, meats, tomatoes, mushrooms, potatoes, grapes, peas, corn, and cheeses such as Parmesan and Roquefort.

The FDA states that MSG is “generally recognized as safe” (GRAS). However, some people identify themselves as sensitive to MSG and report symptoms of headache/ migraine, facial pressure, burning/ tingling, nausea, flushing, chest pain/ palpitations that appear ~20 minutes after consumption and resolve within 2 hours. If this reaction consistently occurs after MSG ingestion, the best treatment is to read ingredient labels and avoid MSG.

A study conducted in 2008 on 752 healthy Chinese participants looked at MSG intake and body mass index (BMI). The population was from rural China and 82% of participants used MSG powder as seasoning in their cooking. Participants were asked to shake out the amount of MSG they added to their daily cooking onto a scale; weighed amounts were recorded. MSG in soy sauce and restaurant foods were also accounted for. Results showed that those who used greater MSG had higher BMI and were more likely to be overweight than non-MSG users.
A 2014 study that looked at specific DIAR newborn mice who were treated with MSG and without. The BMI and blood sugar levels of MSG treated mice was found to be higher. The MSG mice also showed cholesterol accumulation in the liver. However it is important to remember that injecting MSG into neonatal mice is different than a human consuming small amounts of MSG orally within the food supply.

Alternatively, a 2010 study looked at 1282 participants; MSG intake and body weight were assessed in 2002 and then in 2007. When other food items and dietary patterns were accounted for within statistical analysis, no association between MSG and weight gain was found in the study.

Due to conflicting evidence, it is still difficult to clearly determine if MSG leads to weight gain, liver toxicity, increased blood sugar and/ or allergic reactions. A simplified question to ask could be does the use of flavor enhancers lead to more frequent over-eating in our population? If so, how does this affects our choices, health, blood sugar, cholesterol, and weight?

Information Sources:
http://www.hc-sc.gc.ca/fn-an/securit/addit/msg_qa-qr-eng.php
http://www.eatrightontario.ca/en/Articles/Food-allergies-intolerances/The-Truth-about-MSG.aspx#.U4OxP_ldV-g
http://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm328728.htm
http://www.healthcastle.com/msg.shtml
http://www-ncbi-nlm-nih-gov.ezproxy.library.ubc.ca/pubmed/?term=intermap+study+monosodium+glutamate
http://www-ncbi-nlm-nih-gov.ezproxy.library.ubc.ca/pubmed/20370941
http://www-ncbi-nlm-nih-gov.ezproxy.library.ubc.ca/pubmed/24730643