Complementary therapies are an appealing option for many patients with chronic disease. A recent study suggests supplementation with mulberry leaf extract may help decrease blood glucose levels after meals in patients with type 2 diabetes.
Mulberry leaves have a history of anecdotal use in Asia to treat glucose irregularities and studies in diabetic rats have associated ingestion of mulberry leaf extract with a reduction in blood glucose after feeding. Similar results have been reported in uncontrolled and short-term human studies, but there is a need for more thorough investigations on mulberry leaves as a complementary therapy.
A research team at the University of Mississippi recently carried out a randomized double-blind placebo-controlled pilot study to determine whether mulberry leaf extract can be used as a complementary treatment for type 2 diabetes and published their study in Complimentary Therapies in Medicine. A total of 24 non-insulin dependent type 2 diabetic patients who were on oral therapies were recruited into this three-phase study.
In the first phase, all patients took a placebo 3 times daily and monitored their blood glucose to establish baseline levels for a period of 2 weeks. During the second phase, patients were randomized into either a placebo group oral 1000 mg mulberry leaf extract group. Each group ingested their respective capsules 3 times daily along with meals for a period of 3 months. Follow-ups were carried out at 4 weeks and 3 months into this second phase and involved clinical examinations, questionnaires, self-monitoring of blood glucose (SMBG) evaluations and safety laboratory tests. The final phase of the study consisted of A1C hemoglobin assessment to determine average blood glucose levels over the previous 3 months.
Of the 24 patients who enrolled, a total of 17 completed the study. Patients who ingested mulberry leaf extract were found to have a significant decrease in post-meal SMBG level after 3 months compared to placebo. There was no significant change in pre-meal blood glucose levels. Several patients reported adverse gastrointestinal side effects, but there was no difference in these effects between the two study groups. A1C hemoglobin assessments did not find a significant difference between baseline and 3 month follow-up levels between both groups.
The discrepancy between the SMBG and A1C hemoglobin results may be due to the 3 month time period since the authors suggest at least 6 months treatment may be necessary to see changes in A1C hemoglobin. Other limitations of the study include its small sample size, high patient dropout rate, and a baseline difference in weights between the two study groups which may have affected results.
This is the first placebo-controlled study evaluating mulberry leaf extract used in type 2 diabetes over a longer term 3 month period. Results suggest that mulberry leaf extract can help lower blood glucose levels following meals in non-insulin dependent type 2 diabetics. The authors hope that larger scale, longer term trials will be carried out in the future to explore the potential of mulberry leaf extract as a complementary therapy for type 2 diabetes.
Written by Agustin Dominguez Iino, BSc
Riche DM, Riche KD, East HE, Barrett EK, May WL. Impact of mulberry leaf extract on type 2 diabetes (Mul-DM): A randomized, placebo-controlled pilot study. Complementary Therapies in Medicine. 2017;32:105-108. doi:10.1016/j.ctim.2017.04.006.