Does Sourdough Bread Raise Blood Sugar?

During our lockdown in 2020, I jumped on the bandwagon like most of America and started baking sourdough bread at home. I’m a junky for simple foods with intricate preparation processes and learned so much from this YouTube channel, Proof Bread.

Yes, the hardcore keto diet followers of the world will hate me for admitting that, but it is what it is. I love cooking all types of food, despite being a believer that low-carb is the best baseline diet to follow!

The funny thing was in the months prior, my bad eating habits were creeping back up, and I had gained a bunch of weight by eating lots of crappy carbs. Then I realized it would be best if I got my health back to boost my natural immune system.

In the last year, I probably ate cleaner than I ever have in my entire life.

I was cooking everything from scratch, only using whole food ingredients. I seriously did not get takeout once by myself, excluding a few occasions with my immediate family where they were in charge of putting meals on the table.

My one indulgence was sourdough bread every 2-3 weeks in between periods of low-carb maintenance. From what I’ve learned, the fermentation associated with sourdough makes it easier for your body to digest and absorb nutrients.

That’s why I was intrigued to see how sourdough bread affects my blood sugar. In the future, I may try a storebought loaf of bread and see how the results compare.

Below is the macronutrient breakdown for this test.

My baseline measurement was similar to the previous test where I ate four eggs.

The hope was perhaps my glucose didn’t spike as much as you’d think considering bread is a heavy carbohydrate load.

Unfortunately, the 1-hour response was the highest out of any test to date, both in absolute (157 mg/dL) and relative (78%) measurements.

Perhaps the one silver lining was the 2-hour response was lower than several other tests, with only an 8% increase over the baseline reading.

If I had to guess, I think it’s because there wasn’t much fat and protein to dampen the response. Instead, it was mostly simple carbs.

The most comparable macronutrient breakdown is probably the quinoa test at 50 grams of net carbs vs. 58 grams for the sourdough slice. They both have roughly 12 grams of protein and 3 grams of fiber, but the quinoa has a few grams of fat while the bread has almost none.

The responses look quite different, however, with the quinoa registering a 45% increase at 1-hour and a 25% increase at 2-hours.

Could that little amount of fat be the difference?

I’ll be testing quinoa again at some point soon as my first duplicate food. The previous test was back in 2016, so I’m curious as to whether the numbers will be close or not!

Here are the results:

• Date: 5/4/2021
• Food: Sourdough Bread
• Fast: ~15 hours
• Base Blood Sugar: 88 mg/dL
• 1-Hour Response: 157 mg/dL
• 2-Hour Response: 95 mg/dL