A daily supplement of extracts from milk thistle significantly lowered fasting glucose levels by 15 percent, says a randomised clinical trial from Iran published in an international, peer-reviewed journal.
The herbal supplement was also found to have significantly beneficial effects on glycosylated haemoglobin levels, total cholesterol and LDL cholesterol levels, and triglyceride levels on the diabetics who took part in the trial.
“The results are very encouraging, and we now need to do further large multi-centre studies,” said lead author Fallah Huseini, from the Institute of Medicinal Plants, in Tehran, Iran.
Milk thistle (Silybum marianum) has been used for a long time as a food in Europe. Young leaves are used in salads, the stalks eaten like asparagus, and the heads boiled like artichoke.
The research study
The researchers recruited 51 people with type 2 diabetes to take part in the four-month randomised, double-blind, placebo-controlled clinical trial. Subjects were assigned to receive either a daily milk thistle supplement (200mg three times per day) or a placebo (three times per day).
The patients continued their conventional oral hypoglycaemic treatments and were examined monthly.
The researchers, writing in the journal Phytotherapy Research online ahead of print (doi:10.1002/ptr.1988), reported that fasting glucose levels of the supplementation group decreased from 156mg/dL of blood to 133mg/dL, while the placebo group’s fasting glucose levels increased from 167 to 188mg/dL.
Average glycosylated haemoglobin (HbA1c) levels also decreased in the milk thistle extract-supplemented group, by 1,04 percent after four months, compared to the 1,16 percent increase in the placebo group.
Blood levels of total cholesterol (12 percent), LDL cholesterol (12 percent) and triglyceride levels (25 percent) were also significantly reduced as a result of the milk thistle extract supplements. No significant change in the placebo groups’ total cholesterol or LDL cholesterol levels was measured, while triglyceride levels increased by 12 percent.
Exact mechanism unclear
“The results show that although there were no statistically significant differences between the two groups of patients at the beginning of the study, silymarin [milk thistle extract] significantly lowered HbA1c and fasting blood glucose levels in diabetic patients at the end of the study,” wrote the researchers.
The researchers could not say, however, what the actual mechanism behind the effects was, and called for more large multi-centre studies to further investigate the potential role of milk thistle extracts in type-2 diabetes.
“We don’t know the exact mechanism of action for this effect, but this work shows that silymarin could play an important role [against] type II diabetes,” said Huseini. - (Decision News Media, October 2006)
A-Z of Milk Thistle