Are breads made with sourdough significantly healthier than breads made with commercial yeast?
There are many claims out there that sourdough is healthier due to 1) increased digestibility from the yeast cultures, 2) the increased lactic acid, and 3) because there is apparently less gluten in a sourdough bread.
I know a lot of people have trouble digesting breads from the supermarket, but I imagine this is due to the poor quality of the flours used and the numerous preservatives and additives. So taking into consideration that you are baking bread with nothing more than yeast, quality flour, salt, and water- is bread made with levain truly healthier- or are these claims mostly speculative/anecdotal?
Also, there are also poor quality instant yeasts on the market, so also take into consideration that you are using a good quality instant yeast like Le Saffre.
Regarding #1- Aren't there yeast cultures in commercial yeasts as well, and why would they be less healthy than the ones in a sourdough culture, especially if you are starting with a small amount of commercial yeast, and allowing for a long fermentation which would help break down the less digestible properties of flour?
Regarding #2- I've read claims that the increased lactic acid in sourdough lessens the spike in your blood sugar from eating bread. However, eating carbohydrates with fat dramatically decreases any spike in blood sugar- and I think most people eat their bread with butter, olive oil, or as a part of meal that includes protein and fat anyway. So, unless you are eating a ton of bread on it's own, I don't imagine the lactic acid makes a huge difference in maintaining your blood sugar.
Regarding #3- I don't see why this should matter, since bread is a glutinous product either way.
One thing I do notice is that instant yeast has the additive "sorbiton monostearate"- I don't really know anything about this additive or whether it's in significant amounts to worry about.
I'm interested to hear your thought on this, and the reasons you prefer to use sourdough starter other than health benefits. I know bread baked with levain is supposed to have more flavor, but I only have a minimum amount of baking experience so I can't claim this from personal experience yet. I do find the process of maintaining my starter fun, interesting, and rewarding, however. But there is no question that maintaining a starter is a bit more work and commitment than just taking a spoonful out of a jar of instant yeast.