Sunday, October 18, 2020

Seeing Strange Effects of MSG on Blood Sugar; Anyone have an Idea What's Going on?

This is an update on my experiments measuring the effect of dietary supplements and low-carb foods on blood sugar.

Summary:

  • That was a single experiment, though, so I over the last two weeks I repeated the experiment and also tested the effect in combination with insulin.
  • The results were very consistent, with 10g MSG causing a 30 mg/dL (2x) increase in peak blood glucose over 2h. This was 3x higher than the rise observed from MSG alone.
  • Surprisingly, when I tried the same experiment, but with my standard insulin dose, the MSG had virtually no effect (there was an ~10 mg/dL drop in the first couple hours, but this was followed by a rise to the same peak and is within normal day-to-day variation). 
  • I was really surprised by these results, particularly the fact that MSG has such a drastically different effect when taken with vs. without insulin. I'm really not sure what to make of that. The only two hypotheses I can think of are:
    • MSG inhibits endogenous insulin production (leading to the higher blood glucose rise), but does not impact insulin sensitivity (and therefore doesn't impact blood glucose in the presence of injected insulin).
    • MSG promotes gluconeogenesis when insulin concentration is low, but not when it's higher.
  • I'm not sure how to test these hypotheses with what I have available (blood glucose meter). 

Does anyone have other hypotheses as to what might be going on or how to test it? I'm also looking for anyone who might be interested in helping me test this effect. There's a huge range of variables here (amino acid type, quantity, protein/carb/fat ratio of the meal, whether the person has diabetes and what type). 

If you have any ideas or would like to help out, please let me know.

As always, if you have any comments, suggestions, ideas for new experiments, or want to participate, please let me know in the comments or send a PM via the contact form or to quantifieddiabetes_at_gmail.com.


Planned Experiments:

  • Baseline:
    • Glucose re-test
    • Fasting re-test
  • Low-carb foods:
    • Ketochow: Complete
    • Carbquick: Started
    • Eggs
  • Supplements:
    • Vinegar
    • MSG: this post

Preliminary Results: MSG
Figure 1.  Change in blood glucose vs. time for Ketochow + butter (blue), with MSG (orange), with my standard dose of insulin (brown), with insulin & MSG (red), and MSG alone (green).

Figure 2.  Peak blood glucose for Ketochow + butter (blue), with MSG (orange), with my standard dose of insulin (brown), with insulin & MSG (red), and MSG alone (green).


Figure 3.  iAuC for Ketochow + butter (blue), with MSG (orange), with my standard dose of insulin (brown), with insulin & MSG (red), and MSG alone (green).

Ingredient Background
Ketochow is a low-carb meal-replacement that is designed to have all the macro- and micro-nutrients you need to stay healthy. I have it for breakfast and lunch most days. It's extremely convenient and surprisingly good. 

Butter is a solid fat source. I use it with my ketochow meals as it doesn't mix with the powder until melted, giving the mixture excellent shelf-life.

Monosodium glutamate (MSG), is the sodium salt of glutamic acid (an amino acid). It's primarily used in cooking as a umami flavor enhancer. It's also been reported to reduce blood glucose when ingested along with a meal (references here). Most of the reported studies were done with high carbohydrate meals and on non-diabetics, so I was interested to test its effect with low carbohydrate meals for myself.


Procedure
Meals were prepared by mixing the specified quantities chocolate ketochow, butter, and enough hot water to reach a total volume of ~12 oz. MSG was dissolved in ~250 mL of water. Insulin was injected 20 min. prior to the meal. Blood sugar every 30 min for ~270 min. 

Quantities:
  • Control meals (labeled "ketochow + butter" or "+insulin" in graphs:
    • 54g chocolate ketochow, 28g butter
    • 54g chocolate ketochow, 56g butter
    • 54g chocolate ketochow, 56g butter
    • 54g chocolate ketochow, 56g butter, 2.25 units of Novolog insulin
  • Experimental meals (labeled "+MSG" or "+insulin, +MSG" in graphs:
    • 54g chocolate ketochow, 28g butter, 10g MSG
    • 54g chocolate ketochow, 56g butter, 10g MSG
    • 54g chocolate ketochow, 56g butter, 2.25 units of Novolog insulin, 10g MSG
  • MSG control (labeled "MSG" in graphs:
    • 10g MSG


Results
In a previous post, I reported that consumption of MSG significantly increased the rate of rise, peak, and iAuC of my blood glucose. This was really surprising, as the reported literature indicate that MSG reduces blood glucose when ingested with a meal (references here), though all studies I found were done high carbohydrate meals and on non-diabetics.

That was a single experiment, though, so I over the last two weeks I repeated the experiment and also tested the effect in combination with insulin. The results of these experiments are showing in Figures 1-3. The replicates of the previous experiments were extremely consistent: Ketochow + butter causes a consistent rise of ~30 mg/dL over ~2h, while the same meal with 10g MSG resulted in a rise of 60 mg/dL in the same time period. This is a 2x increase. 

As a control, I tested consumption of 10g MSG with no accompanying meal. This resulted in a rise of ~10 mg/dL over ~2h, only 30% of the increase caused by consuming MSG with a meal. This indicates a synergistic effect of consumption of MSG with a meal.

As a second test, I tried consuming MSG with my normal meal and insulin dose. Surprisingly, in this case the MSG had virtually no effect (there was an ~10 mg/dL drop in the first couple hours, but this was followed by a rise to the same peak and is within normal day-to-day variation). 


Discussion and Next Steps
I was really surprised by these results, particularly the fact that MSG has such a drastically different effect when taken with vs. without insulin. I'm really not sure what to make of that. The only two hypotheses I can think of are:
  • MSG inhibits endogenous insulin production (leading to the higher blood glucose rise), but does not impact insulin sensitivity (and therefore doesn't impact blood glucose in the presence of injected insulin).
  • MSG promotes gluconeogenesis when insulin concentration is low, but not when it's higher.
I'm not sure how to test these hypotheses with what I have available (blood glucose meter). 

Does anyone have other hypotheses as to what might be going on or how to test it? I'm also looking for anyone who might be interested in helping me test this effect. There's a huge range of variables here (amino acid type, quantity, protein/carb/fat ratio of the meal, whether the person has diabetes and what type). If you have any ideas or would like to help out, please let me know.

While waiting to see what others think, I'm going to test the bounds of the effect. I took a huge amount of MSG, far more than is used in cooking. I'm going to evaluate smaller quantities as well as alternate amino acids to better understand the effect.


- QD

Sunday, October 11, 2020

October Blood Glucose Stats & Upcoming Experiments

I'm about a week late on this, but here's an update on my monthly blood glucose stats. As before, I'll be looking at average blood glucose, coefficient of variation, and time in range

Here's the data broken out by month:


Figure 1.
 Average blood glucose (blue) & coefficient of variation (orange) by month.


Figure 2. Time-in-range vs. month.


Figure 3. Time-in-range vs. month, excluding "in-range."


No improvement vs. August. However, I had two bad sensors in September, which resulted in periodic large mismatches between my CGM and fingerstick meter. I don't have the data to quantify the impact, but I suspect that that was responsible for a substantial fraction of the Low and High time. A quick look at the first 1.5 weeks in October shows that I'm on trend for a meaningful drop in Low (currently 3%) with no change in average glucose (still 90 mg/dL). We'll see if it holds up.


Planned Experiments:

  • Baseline:
    • Glucose re-test
    • Fasting re-test
  • Low-carb foods:
    • Carbquick
    • Eggs
  • Supplements:
    • Vinegar
    • MSG: Preliminary tests here. I tried again, but this time while taking insulin, and saw no effect. I'm going to repeat the original test and then other variations to try to figure out what's going on.

As always, if you have any comments, suggestions, ideas for new experiments, or want to participate, please let me know in the comments or send a PM via the contact form or to quantifieddiabetes_at_gmail.com.


- QD

Sunday, October 4, 2020

Effect of Dietary Supplements & Low Carb Foods: Ketochow, Butter, & MSG

This post is an update on my experiments measuring the effect of dietary supplements and low-carb foods on blood sugar. This is going to be an on-going exploration. Rather than wait for complete sets of data (which would take a long time), I'm going to post each weeks worth of data as I collect it in the hopes of soliciting feedback to guide later experiments.

As always, if you have any comments, suggestions, ideas for new experiments, or want to participate, please let me know in the comments or send a PM via the contact form or to quantifieddiabetes_at_gmail.com.


Planned Experiments:

  • Baseline:
    • Glucose re-test
    • Fasting re-test
  • Low-carb foods:
    • Ketochow: This post
    • Carbquick
    • Eggs
  • Supplements:
    • Vinegar
    • MSG: Started 10/2


Preliminary Results: Ketochow, Butter, and MSG
Figure 1.  Change in blood glucose vs. time for Ketochow by itself (blue) and with 28g butter (orange), 73g butter (light blue), and 28g butter + 10g MSG (red).

Figure 2.  Peak blood glucose for Ketochow by itself (blue) and with 28g butter (orange), 73g butter (light blue), and 28g butter + 10g MSG (red).


Figure 3.  iAuC for Ketochow by itself (blue) and with 28g butter (orange), 73g butter (light blue), and 28g butter + 10g MSG (red).

Ingredient Background
Ketochow is a low-carb meal-replacement that is designed to have all the macro- and micro-nutrients you need to stay healthy. I have it for breakfast and lunch most days. It's extremely convenient and surprisingly good. I prepare 16 meals at a time and keep them in the fridge. When it's time for a meal, I just add hot water, mix, and wait for my insulin to kick in; about 1 min. total prep. time (all-in). It also comes in 18 different flavors, so I can rotate through the ones I like and not get bored. I've been using Ketochow for years, so I've got my insulin dose pretty well tuned for it. However, following a Reddit post by Chris Bair, the owner of Ketochow on its Glycemic Index, I decided to do a detailed test of its impact on my blood sugar.

Butter is a solid fat source. I use it with my ketochow meals as it doesn't mix with the powder until melted, giving the mixture excellent shelf-life.

Monosodium glutamate (MSG), is the sodium salt of glutamic acid (an amino acid). It's primarily used in cooking as a umami flavor enhancer. It's also been reported to reduce blood glucose when ingested along with a meal (references here). Most of the reported studies were done with high carbohydrate meals and on non-diabetics, so I was interested to test its effect with low carbohydrate meals for myself.


Procedure
I consumed 1.1 servings of the chocolate ketochow (54g, my normal amount) and the specified quantities of butter and MSG mixed with hot water to a total volume of ~12 oz. I then monitored my blood sugar every 30 min for ~270 min. 


Results
As shown in Figure 1, plain Ketochow shows a slow rise of ~40 mg/dL over ~2h. As discussed previously, this is similar to whey protein (the primary caloric ingredient in Ketochow is an 80:20 mix of casein & whey protein) and pretty much what you'd expect from the nutrition label and the amount of insulin I use to cover the meal.

Much more interesting is the impact of butter and MSG. The addition of butter significantly slowed the rise in blood glucose and gave an ~25% reduction in peak blood glucose and 30% reduction in iAuC. Interestingly, increasing the amount of butter from 28 to 73g did not increase the effect, though that was only a single experiment and I need to repeat it to confirm.

For MSG, in contrast to the reported literature, it significantly increased the rate of rise, peak, and iAuC of my blood glucose. This was a single experiment and I haven't yet done the proper controls (e.g. MSG by itself), but the magnitude of the effect was much larger than I would expect from the amount of amino acid consumed, suggesting it is real. Going forward, I'm going to test MSG by itself, smaller quantities, and also combined with glucose instead of protein fat (more similar to the literature. 


Interim Thoughts and Next Steps
From this preliminary data, it looks like there are meaningful effects of combining macronutrients as well as supplements. Given that, I'm going to stick with this line of experiments. I also like this approach of posting interim data as I collect it, then writing up a more detailed report & analysis once there's enough data to merit it.

As always, please let me know if you have any thoughts or suggestions.


- QD