Or in laymen’s terms, consuming an acidic food/ingredient alongside carbohydrates will decrease the size of the resulting blood sugar spike in your bloodstream.
This is part of the reason why sourdough bread (which contains lactic acid, produced by the lactobacillus bacteria that are involved in the fermentation of sourdough bread) has a lower glycemic index, compared to regular bread.
The mechanism for how acid decreases blood sugar is uncertain. Some research has suggested that acid delays gastric emptying (the release of food from your stomach), while other studies have postulated that it may inactivate the amylase enzyme that breaks down carbohydrate.
Either way, this random food fact gives insight into the unique power that foods have when consumed in combination. So don’t hesitate to squeeze some lemon on those potatoes, it could do you some good!
I learned about this fact from:
Liljeberg HG and Björck IM. Delayed gastric emptying rate as a potential mechanism for lowered glycemia after eating sourdough bread: studies in humans and rats using test products with added organic acids or an organic salt. Am J Clin Nutr. 1996 Dec;64(6):886-93.