Vinegar at mealtimes reduces risk factors for type 2 diabetes
Ingesting vinegar with meals reduced fasting blood glucose levels in an immediate and sustained manner in health adults who were at risk for type 2 diabetes, according to a new study from Arizona State University.
These effects were noted even though no other changes were made to participants’ diets.
The 12-week pilot study, published on 4 August 2013 in the Journal of Functional Foods, examined the effects of vinegar on markers of type 2 diabetes in at-risk adults. Average change in fasting glucose was reduced in the participants ingesting vinegar with meals, and fasting breath hydrogen (a measure of digestive processes) was elevated by 19 per cent. The average changes in fasting glucose were similar in the first six weeks of the study, and in weeks 7 to 12 of the study.
Researchers said the data indicated that vinegar has antiglycaemic effects in adults at-risk for type 2 diabetes.
How vinegar helps
Although the mechanisms of vinegar are unclear, it is thought that acetic acid, the defining ingredient of all vinegars, may interfere with carbohydrate ingestion, promote glucose uptake by muscle and/or increase beta cell insulin secretion.
In adults with type 2 diabetes, previous research has shown that daily ingestion of vinegar lowered fasting glucose concentrations and glycated hemoglobin (A1c). But the Arizona State University researchers said to date there has not been a long-term trial examining the efficacy of daily vinegar ingestion for lowering markers of diabetes in at-risk adults.
Participants were paired by gender, age, body mass index (BMI) and prediabetes diagnosis, and randomly assigned to the vinegar (drink) or control (pill) group. Participants maintained customary diet and activity patterns during the study and measured blood glucose concentrations twice daily, upon waking in a fasting state and 2 hours after the evening meal, using a calibrated glucometer with memory.
The study treatments (vinegar: 8 oz vinegar drink; control: 1 vinegar pill) were ingested twice daily with meals. The commercially available vinegar contained 1 tablespoon of vinegar (750mg acetic acid) per 8 oz. The commercially available vinegar pills contained trace amounts of acetic acid (40mg/tablet).
Baseline characteristics did not differ between groups but fasting glucose concentrations and A1c were elevated in participants diagnosed with prediabetes compared to other participants. A1c serves as a marker for average blood glucose levels over the months prior to the measurement.
Reported treatment compliance was 89 per cent of study days for the drink group and 77 per cent for the pill group.
Researchers said elevations in colonic fermentation, as evidenced by the increase in breath hydrogen and methane measurements, suggested that the anti-glycaemic effect of vinegar is related in part to carbohydrate maldigestion.
The research was funded by the Nutrition Research Fund of the Arizona State University Foundation, and vinegar products were donated by Bragg Live Food Products and the General Nutrition Corporation.
Diabetes rates in US and Australia
The prevalence of type 2 diabetes in the US and worldwide approaches 10 per cent and is predicted to rise in the coming decades. The risk of developing type 2 diabetes is estimated to be as high as 50 per cent for US adults older than 65.
In Australia, diabetes is the fastest growing chronic disease, with an estimated 280 Australian developing diabetes every day. Nearly 1 million Australians are currently diagnosed with diabetes, and in August 2013 the results of the most recent Australian Health Survey found that around one in five adults were not aware they had diabetes.
According to Diabetes Australia, the total number of Australians with diabetes and pre-diabetes is estimated to be 3.2 million. Up to 60 per cent of cases of type 2 diabetes can be prevented, according to Diabetes Australia.