Vinegar is an interesting food. It is tangy and tart, yet has a subtle sweetness that can seriously dress up a salad. But did you know that vinegar can help the body control blood glucose levels, and even reduce type 2 diabetes?
Vinegar exerts glycemic control
Research from Greece's Athens University Medical School tested 11 people with type-2 diabetes. They were tested twice, with a week between each test. Before the tests, the researchers examined the patients' plasma glucose, insulin, triglycerides, nonesterified fatty acids (NEFA), and glycerol.
Then they gave each patient either 30 milliliters of vinegar (6% acetic acid) or water (placebo) during a meal. They proceeded to test the patients' blood parameters every 30-60 minutes for the next five hours after the meal.
The researchers found that the vinegar significantly increased the diabetic patients' uptake of glucose within their cells. They also had reduced blood sugar levels. This was found by testing blood from the radial artery and from the forearm vein.
The research also found that the vinegar reduced blood levels of insulin and triglycerides.
The researchers concluded:
In type-2 diabetic patients, vinegar reduces postprandial hyperglycaemia, hyperinsulinaemia, and hypertriglyceridaemia without affecting lipolysis. Vinegar's effect on carbohydrate metabolism may be partly accounted for by an increase in glucose uptake, demonstrating an improvement in insulin action in skeletal muscle.
This last point is critical. The reduced levels of insulin in the blood along with reductions in blood glucose levels means one thing: That the vinegar reduced what is referred to as insulin resistance.
What is even more profound in this study is the fact that the vinegar had such an immediate effect.
When the researchers tested the patients a second time, but with different people taking the vinegar versus placebo, they found the same results.
Not the first study showing vinegar's effect on blood sugar
A 2010 study from Athens University Medical School also found that adding vinegar to a high-glycemic meal results in reduced blood sugar and insulin levels among diabetics.
The researchers divided 16 type 2 diabetes patients into two matched groups. Those in the first group were given a meal with a high glycemic index - including mashed potatoes and low-fat milk. The first day of the meal, vinegar was added to the meal. On the second day of the meal, vinegar was not included in the meal.
The second group was given a meal of the same nutritional value, except that it had a lower glycemic index. This meal included whole grain bread, low-fat cheese and lettuce. Once again they were given the meal on two consecutive days, with and without vinegar.
After each meal, each subject was tested for plasma glucose and insulin levels every thirty minutes for two hours.
Among the first group - those who ate the high-glycemic meal - blood glucose levels were significantly lower after the vinegar meals. Their glucose levels averaged 181 mmol min/l, while the patients who ate the high-glycemic meal without the vinegar averaged 311 mmol min/l glucose levels. In other words, blood glucose levels were nearly 42% lower after the high-glycemic meal with vinegar.
Insulin levels were also significantly reduced after vinegar was added to the first meal. The vinegar-added meal counts averaged 2368 microU min/ml, and the non-vinegar-added meal insulin counts averaged 3545 microU min/ml for IiAUC(120).
However, the difference between the blood sugar levels and insulin levels among the second group - those eating low-glycemic meals with and without vinegar - were not significantly different. Still, however, the vinegar meals resulted in lower levels, with 229 mmol min/l versus 238 mmol min/l for blood sugar and 2996 microU min/ml versus 3007 microU min/ml for insulin counts among the with- and without-vinegar meals, respectively.
The researchers concluded that:
The addition of vinegar reduces postprandial glycemia" following a high-glycemic meal among diabetic patients."
Other studies have confirmed similar findings for vinegar.
The research also clearly shows one of the health benefits of adding vinegar to our meals. Many health experts have heralded numerous benefits of raw apple cider vinegar, for example.
Why is vinegar such a source of health? Because it has been fermented by probiotic bacteria.
Lim J, Henry CJ, Haldar S. Vinegar as a functional ingredient to improve postprandial glycemic control-human intervention findings and molecular mechanisms. Mol Nutr Food Res. 2016 Aug;60(8):1837-49. doi: 10.1002/mnfr.201600121.
Mitrou P, Petsiou E, Papakonstantinou E, Maratou E, Lambadiari V, Dimitriadis P, Spanoudi F, Raptis SA, Dimitriadis G. Vinegar Consumption Increases Insulin-Stimulated Glucose Uptake by the Forearm Muscle in Humans with Type 2 Diabetes. J Diabetes Res. 2015;2015:175204. doi: 10.1155/2015/175204.
Mitrou P, Petsiou E, Papakonstantinou E, Maratou E, Lambadiari V, Dimitriadis P, Spanoudi F, Raptis SA, Dimitriadis G. The role of acetic acid on glucose uptake and blood flow rates in the skeletal muscle in humans with impaired glucose tolerance. Eur J Clin Nutr. 2015 Jun;69(6):734-9.
Liatis S, Grammatikou S, Poulia KA, Perrea D, Makrilakis K, Diakoumopoulou E, Katsilambros N. Vinegar reduces postprandial hyperglycaemia in patients with type II diabetes when added to a high, but not to a low, glycaemic index meal. Eur J Clin Nutr. 2010 Jul;64(7):727-32.