Postmenopausal women may be able to combat the threat of diabetes by having a couple of alcoholic drinks a day, report researchers from the US.
The team from the Beltsville Human Nutrition Research Center, part of the US Department of Agriculture, said that the positive effects could be achieved from any kind of alcohol.
The researchers based their study on previous data which had shown that moderate alcohol intake could help improve insulin sensitivity in non-diabetic individuals. However, there had never been any controlled-diet studies which addressed the effects of daily moderate alcohol consumption on fasting insulin and glucose concentrations and insulin sensitivity.
With this in mind, the Beltsville team recruited 63 healthy postmenopausal women to take part in the trial, which was conducted at a clinical research centre in Maryland between 1998 and 1999. Participants were randomly assigned to consume 15 or 30 grams of alcohol (in an orange juice and ethanol mixture) per day for an eight-week period as part of a controlled diet. Another randomly assigned group consumed no alcohol at all during the period, and was instead given an isocaloric beverage.
The researchers measured fasting insulin, triglyceride and glucose concentrations at the end of each dietary period, as well as insulin sensitivity. They discovered that the group which consumed 30g/day of alcohol reduced fasting insulin levels by 19.2 per cent compared to the no-alcohol group. Triglyceride concentration was reduced by 10.3 per cent and insulin sensitivity was increased by 7.2 per cent.
There was no difference in the response of normal-weight, overweight and obese individuals.
The effects were less marked for the 15g/day group, which only showed a significant reduction in fasting triglyceride concentration compared to the no-alcohol group (7.8 per cent lower). There was no difference between consumption of 15 and 30g/day of alcohol, and fasting glucose concentrations were the same in all groups.
The team stressed that the trial had been carried out on only a small number of participants, and that more research was necessary to confirm the findings. Furthermore, since the researchers used ethanol - pure alcohol - in the trial, it is still unclear whether similar effects would be seen from 'normal' alcohol consumption.
The research was published in the latest edition of the Journal of the American Medical Association.