Duckweed plant beneficial for diabetes? Mankai duckweed shows potential in glycemic control

06 Aug 2019 --- Mankai, a high-protein aquatic plant strain of duckweed, has shown potential in providing glycemic control after carbohydrate consumption. This is according to a study from Ben-Gurion University of the Negev (BGU), Israel. Touted as a “superfood,” Mankai is a highly sustainable plant that requires little water in its cultivation and could also be used as an alternative, plant-based protein ingredient. The new study, published in Diabetes Care, the official journal of the American Diabetes Association (ADA), highlights Mankai’s potential in controlling blood sugar levels and curbing appetite.

The Mankai duckweed aquatic plant is grown in Israel and other countries in a closed environment and it’s sustainable angle lies in that it requires only a fraction of the amount of water to produce each gram of protein compared to soy, kale or spinach. It can also be grown year-round using hydroponic cultivation.

In the study, Hila Zelicha, a registered dietician and Ph.D. student in the BGU Department of Public Health, and her colleagues researched the glycemic aspect of Mankai duckweed. The researchers compared Mankai shake consumption to a yogurt shake equivalent in carbohydrates, protein, lipids and calories. Following two weeks of monitoring with glucose sensors, participants who drank the duckweed shake showed a much better response in a variety of measurements including lower glucose peak levels, morning fasting glucose levels, later peak time and faster glucose evacuation. The participants also felt more full.

Duckweed has been consumed for hundreds of years in Southeast Asia, where it is known as “vegetable meatball” due to its high-protein content.The research group, led by Professor Iris Shai, a member of BGU's S. Daniel Abraham International Center for Health and Nutrition and the School of Public Health, has found in several previous studies that Mankai duckweed has tremendous health potential as a superfood. This new research is a sub-study of the Dietary Intervention Randomized Controlled Trial – Polyphenols Unprocessed, which explores the effects of a green Mediterranean diet.

Duckweed has been consumed for hundreds of years in Southeast Asia, where it is known as “vegetable meatball” due to its high-protein content – more than 45 percent of the dry matter. It includes the complete protein profile of eggs, containing all nine essential and six conditional amino acids. In addition, Mankai is very rich in polyphenols, mainly phenolic acids and flavonoids (including catechins), dietary fibers, minerals (including iron and zinc), vitamin A, vitamin B complex and vitamin B12, which is rarely produced by plants.

A previous duckweed study conducted by Alon Kaplan, a Ph.D. student in Professor Shai's lab, published in Clinical Nutrition, showed that the absorption of the essential amino acids from Mankai was similar to the soft cheese and plant (peas) equivalent in protein content, reinforcing its role as a high-quality protein source.

Furthermore, a study published earlier this year in the Journal of Nutrition by BGU Ph.D. student Anat Yaskolka Meir R.D. indicates that a Mediterranean diet with Mankai, elevates iron and folic acid levels, despite low quantities of red meat. This study also determined that iron from Mankai was efficient in treating iron-deficiency anemia in anemic rats to the same degree as the common treatment.

It is the collection of all of these properties which seem to make the easily integratable, tasteless and odorless Mankai plant, a good candidate to become a superfood, the researchers explain. Harvard University apparently agrees, as Mankai smoothies were introduced in the Harvard School of Public Health cafeteria recently.

Edited by Kristiana Lalou