This is an N of 1 study on a specific supplement that reportedly has the outcome of lowered blood glucose levels. In June of 2015 I went on a ketogenic diet. I was enjoying the benefits of weight loss and increased alertness, but I noticed my blood glucose was creeping up in the daily readings. I wanted to see if I could turn that around and bring the readings lower.
I heard on the Ben Greenfield Fitness podcast that Bitter Melon lowers blood glucose levels. I purchased the supplement and decided to test it. The results were surprising, but not in a fun way.
Is Bitter Melon effective for in lowering my blood glucose and should I continue to take it?
What I Did
I took Bitter Melon on a randomized schedule for 20 days, then took it every day for another 14 days. As I did so, I recorded my glucose levels after waking, at 10am, and 3pm each day.
How I Did It
I used a Google Spreadsheet to generate a random “one” or “zero” for each day in the 20 day randomized period. This gave me instructions on whether or not to take the Bitter Melon. After 20 days, I took it every day for 13 days.
The daily dose was two tablets, which is 900mg of the supplement. I excluded readings on days where food intake was outside of a normal range, or something extraordinary was happening like a flight or no sleep.
At the end of the period, I looked at the difference on the randomized days using a TTest. I also looked at the effect on my glucose for the period where I was taking the supplement every day.
What I Learned
I had a disappointing outcome with Bitter Melon protocol. There was no change in the continued climb in my blood glucose levels. This graph shows the period from the beginning of the diet to the end of the Bitter Melon test:
The period of taking Bitter Melon was from 8/9/2015 onward, so for me it appeared to be ineffective in arresting the upward movement of the glucose levels.
The first measure I looked at was the morning readings based on having taken the supplement the day prior. There was no effect: p=.84. Recall that to have demonstrated a significant difference in the two data sets we are looking for p<.05.
The second measure was a 10am reading after having taken the pills at around 7am. Doing the TTest comparing the days where I had taken the supplement vs. not there was no effect: p=.25.
The final measure I compared was a measure at 3PM, comparing the days where I had ingested Bitter Melon vs. not. The test showed a significant difference (P=.057), but the result was reversed from what I would expect. The average glucose reading on the days I took Bitter Melon was higher than days I did not take the pills. That is an odd outcome.
Finally, looking at the effect of taking the supplement daily there was no significant change in the morning glucose level taking an intermittent dose versus a daily dose (p=.17).
As a result of this analysis I will no longer take Bitter Melon and save myself the money. And the data opens up another line of research. Something is driving my glucose levels upward. I am tracking my food intake and my carbohydrates are very low. I am not eating any processed foods. The next step is to eliminate all supplements and see if the source is there as well as up my fiber levels. One thing is for sure. A “one size fits all” ketogenic diet ripped straight from the podcasts is not the cure all for my physiology. Nor is it probably for yours either.