|"Now you've got me confused!"|
With 9 perfectly healthy, recreationally active men aged 23.9+/-1.9y and a BMI of 25kg/m² the results can however be taken as being representative for at least large parts of the ever-decreasing number of "normal-weight" individuals.
There is a potential string attached
Usually, the "on the other hands", are something I am talking about at the end of the article, but in this case, of which I expect that it's going to become pretty controversial it appears prudent to address them right away: there was a hitherto unexplained dichotomy in the insulin response of the 9 subjects after the ingestion of the 150 mg/kg body weight MSG or placebo capsules, the subjects ingested after an overnight fast and 30 minutes before they consumed a 75 g carbohydrate or a non-energy placebo drink.
|Figure 1: AUC for glucose and insulin across the trials (left); serum insulin and glucose concentrations in the post-prandial period during the glutamate and no-glutamate trials (Sebastiano. 2013)|
On average, we do the the same if not less insulin with a greater reduction in glucose
That being said, there is no debating that contrary to the scientists' working hypothesis, the average insulin secretion was not on augmented in the GLU+CHO, while the onslaught of glucose was significantly reduced (see figure 1, bottom right) compared with the CHO only trial.
Now this is quite astonishing as it would suggest that the co-ingestion of glutamate does actually improve the insulin sensitivity only in some. In those the effect must yet have been so pronounced, though, that the "non-responders" didn't carry any weight...
"[I]t appears that glutamate, when combined with carbohydrate, elicits one of two insulin responses, depending on the individual.
Epidemiology paints a different picture of MSG (learn more)
Although the present study was not designed to explore this question, we did remark that the differences between these two groups of participants were not explained by factors associated with glucose handling, such as habitual activity levels (assessed using the Baecke questionnaire), fasting glucose, available glutamate or insulin sensitivity." (Sebastiano. 2013)
Apropos weight, in order to confirm whether or not you can use glutamate to your advantage, we would need at least two follow up studies:
- One study to elucidate the long-term consequence of the addition of glutamate to every (high) carbohydrate meal in healthy human subjects (the hypothesis would be that we should lower HOMA-IR and HbA1C levels as a sign of improved glucose metabolism).
|Will the additional butter on top of the potatoes reduce the insulin response? Learn the answer to this other questions in one of the famous installments of the "True or False?" Series on the SuppVersity (learn more)|
- And another study to make sure that the obvious insulin-sensitizing effects glutamate appears to exert in at least some subjects are not adipose-tissue specific - or, in other words, that it is not an increase in fatty acid synthethase and subsequent storage of glucose as fat that's behind the significantly reduced glycemia the scientists observed.
|YamYol: Yeast extract = MSG|
- Di Sebastiano KM, Bell KE, Barnes T, Weeraratne A, Premji T, Mourtzakis M. Glutamate supplementation is associated with improved glucose metabolism following carbohydrate ingestion in healthy males. Br J Nutr. 2013 Jun 11:1-8. [Epub ahead of print]
- Verdich C, Toubro S, Buemann B, Lysgård Madsen J, Juul Holst J, Astrup A. The role of postprandial releases of insulin and incretin hormones in meal-induced satiety--effect of obesity and weight reduction. Int J Obes Relat Metab Disord. 2001 Aug;25(8):1206-14.