But mulberry splits along two lines, both of which were mentioned on the show: ingredients from the fruit, and those from the leaf. The fruit yields an anthocyanin-rich extract which has been shown to have weight management potential in a recent mouse study. And extracts of the leaf have been shown to have blood sugar management potential.
“The genie is out of the bottle, a relatively inexpensive botanical that is excellent for reducing blood sugar along with maintenance of a healthy lipid profile (triglycerides)has been brought to the forefront by Dr Oz. Combined with the many studies and the quick beneficial provable result this is a formula for mulberry leaf extract to emerge as a main stream botanical extract,” Frank Li, president of California-based distributor Phytochem International Inc. told NutraIngredients-USA.
India-based manufacturer Phytotech Extracts PVT has been selling the extracts in Japan for more than a decade and recently entered the South Korean market. The company only recently started bringing the extracts to the US through their North American distributor Phytochem.
Method of action and science backing
The main actives in mulberry leaf extract is a compound called 1-deoxynojirimycin (DNJ) and some of its derivatives, all of which fall under the umbrella of iminosugars, which are reported to inhibit the activity of a carbohydrate digesting enzyme called alpha-glucosidase. By slowing or stopping this enzyme, the digestion of starch and oligosaccharides is slowed, which suppresses blood glucose spikes after eating.
Mulberry leaf extracts have a history of use for blood sugar management, with the extracts being used to treat diabetes in some Asian countries.
DNJ is similar in its chemical structure to Acarbose; a synthetic analogue and prescription drug in Germany, China and elsewhere. This drug works as an alpha-glucosidase inhibitor and is used to treat Type II and pre-diabetes. In the US it is sold under the brand name Precose.
According to Phytochem, mulberry leaves also contain number of essential phytonutrients and many other phytochemical such as Flavonoids, Vitamin C, quercetin, isoquercetin and anthocynidines which are believed to be responsible for reducing the blood sugar level and for maintenance of a healthy lipid profile. It’s also high in Vitamin C.
There have been some recent studies supporting the action of mulberry leaf extracts, including one in South Korea in which the extracts showed a positive effect on blunting post-prandial blood glucose spikes.
Mulberry leaf ingredients are available as encapsulated powders, ratio extracts, and standardized extracts. As with all botanicals, the strength of the actives varies, depending on the source material. And adulteration can be issue.
According to Phytotech, Phytochem’s Indian supplier, bargain basement mulberry ratio extracts may be understrength, or may be diluted with excipients such as maltodextrin. And low quality extracts may be extracted with hexane or other problematical solvents.
As for the standardized extracts, caution must be used to guard against products that have been laced with synthetic DNJ, according to Venkitachalam Harihan, CEO of Phytotech.
“There is fake material and adulterated extract (with synthetically produced 1-DNJ molecule) in the market. Be very careful about purchasing cheap Mulberry Extract from such a supplier,” he said.
Just a fad?
As with all botanicals that have benefited from Dr Oz publicity, the question arises, how long will the demand remain strong? In the case of mulberry leaf extract, the prospects look good, in that it has strong science backing and is relatively inexpensive.
In addition, the ingredient is said to manifest its blood sugar management properties quickly, giving customers immediate positive feedback, said Tom Winn, sales and marketing manager for Phytochem.
“Whenever the result of taking a botanical extract is easily measurable and the result is very good, the botanical becomes very popular and eventually goes mainstream,” Winn said.
And Winn said the potential market is big. Statistics from the American Diabetes Association showed that in 2011, 25.8 million children and adults in the US suffered from diabetes.
Source: Journal of Functional Foods
Volume 5, Issue 3, Pages 1502–1506, doi: 10.1016/j.jff.2013.04.015
“Acute intake of mulberry leaf aqueous extract affects postprandial glucose response after maltose loading: Randomized double-blind placebo-controlled pilot study”
Authors: H.I. Chung, J. Kim, J.Y. Kim, O. Kwon