I AM NOT A DOCTOR THIS IS INFORMATIONAL ONLY
In general our goal is to keep out blood sugar relatively low, as high blood sugar leads to high insulin levels, leads to the potential of developing insulin resistance and potentially type 2 diabetes. I remember reading somewhere long ago that vinegar helped to suppress blood glucose levels, and curiosity led me to look into it.
The literature generally seems to point towards delayed gastric emptying as one of the mechanisms that vinegar may use to suppress blood sugar. Delayed gastric emptying basically means that the food stays in your stomach for longer, so the sugars from it are more gradually released into the blood stream. The more gradual release means that your body does not need to produce the same amount of insulin to counteract it.
This study published in Nature, does show a significant decrease in blood glucose levels and an increase in satiety (feeling of fullness), and insulemic response. This suggests that vinegar does have a significant effect on our body post meal.
However, it appears the effect may be more complicated than just a slowing of gastric emptying. This study shows that taking vinegar at bedtime was able to reduce fasting glucose in the morning for Type 2 diabetics, with a suggestion that acetic acid (the acid in vinegar) may contribute to a change in glycolysis. Glycolysis is the freeing of glucose molecules from storage in the liver and muscles.
These studies seem to suggest that vinegar may play a useful role in regulation of blood glucose levels. It seems especially useful around mealtimes. It’s even better news since so many foods can be improved with the addition of a little bit of vinegar.