They tracked four men and seven women who have type 2 diabetes and were not taking insulin. These people kept 24-hour diet records for three days and measured their fasting blood glucose at 7 a.m. for three consecutive days. They took either 2 tablespoons of apple cider vinegar or water at bedtime with 1 ounce of cheese (8 grams of protein, 1 gram of carbohydrate, and 1.5 grams of fat).

The result was that when they took the vinegar, they cut their fasting blood glucose by about 5 mg/dl (0.26 mmol/l). That was twice as much as what the placebo group did.

And when Dr. Johnston and her associate took a closer look at the data, they found that the vinegar treatment was particularly effective for those people who had a typical fasting blood glucose level of more than 130 mg/dl (7.2 mmol/l). Vinegar helped this group reduce their fasting blood glucose by 6 percent compared with a reduction of 0.7 percent in those people who had a typical fasting blood glucose of less than 130 mg/dl (7.2 mmol/l).

It might not have been just the vinegar that was at work, the authors concluded. Cheese might have a synergestic effect with it. Nobody knows yet, and taking it with the vinegar could be a good idea, especially since it makes the vinegar more palatable.

But “this is the first report describing a hypoglycemic effect of vinegar apart from mealtime,” they concluded. It is a big step forward in our continuing attempts to control the dawn phenomenon.

UPDATE January 9, 2008: Another strategy to control the dawn phenomenon may be to drink a little alcohol with dinner. A study reported in the December 2007 issue of Diabetes Care that the fasting plasma glucose of volunteers who drank 13 grams of wine in the three-month trial dropped 32.5 mg/dl compared with those in the control group.