By David Mendosa
Most of us know that when we eat protein, fat, or fiber our blood glucose levels won’t go up. Yet few of us are aware of other foods that will actually reduce these levels. All you need is a little acid. But it matters a lot what type of acid.
Acetic acid seems to be the most effective. You don’t eat or drink acid? Actually, acetic acid is the chief acid of vinegar. The best types to use are red or white wine vinegars. The most common vinegar, white, is cheap but somewhat harsh-tasting, so it’s not a good choice for most recipes. The other common vinegar, cider vinegar, is milder and less acidic. The less common but well-known balsamic vinegar is much sweeter and would probably be a poor choice. So too is rice vinegar, which has a sweet flavor and light acidity. Vinegar is a key ingredient in several different dishes. Typically, it is used together with oil to dress salads and vegetables. Its presence in pickles is also noticeable. Lemon juice is just as powerful as vinegar. Lime juice is likely to work just as well. A surprisingly small amount is effective. A typical vinaigrette dressing of oil and vinegar works well and can taste wonderful. Add mustard powder, garlic, and your favorite spices. The glucose response in one study with vinegar was 31 percent lower than without it. In another study vinegar significantly reduced the glycemic index of a starchy meal from 100 to 64 (where white bread = 100).
Fermented foods also reduce blood glucose levels. The natural fermentation of starch and sugars by a yeast starter culture that produces lactic and propionic acid is what makes sourdough bread. In a third study the glycemic index of sourdough bread was 68 compared 100 for non-sourdough bread. All these foods will help you hold your blood glucose in check. They do that by slowing the speed with which your stomach empties. Your best bet is to include a side salad with an olive oil and vinegar or lemon dressing in as many meals as possible. Your body will thank you.
Liljeberg H, Bjorck I. “Delayed gastric emptying rate may explain improved glycaemia in healthy subjects to a starchy meal with added vinegar.” Eur J Clin Nutr. 1998 May;52(5):368-71.
Liljeberg HG, Lonner CH, Bjorck IM. “Sourdough fermentation or addition of organic acids or corresponding salts to bread improves nutritional properties of starch in healthy humans.” J Nutr. 1995 Jun;125(6):1503-11.
Brighenti F, Castellani G, Benini L, Casiraghi MC, Leopardi E, Crovetti R, Testolin G. “Effect of neutralized and native vinegar on blood glucose and acetate responses to a mixed meal in healthy subjects.” Eur J Clin Nutr. 1995 Apr;49(4):242-7.
Brand-Miller, Jennie, Kaye Foster-Powell, and David Mendosa. “What is the advantage of vinegar, lemon juice, and sourdough bread?” in What Makes My Blood Glucose Go Up…and Down? New York: Marlowe & Company, 2003, p. 141-2.
This is by far the most extensive discussion of the advantage of acidic foods in the popular literature.