White Mulberry (Morus alba) - From Folklore to Fact

What Is Mulberry Leaf?

Morus alba, known as white mulberry, is a fast-growing, medium sized tree. The ripe fruit is edible and is widely used in pies, tarts, wines and tea and the leaves are used medicinally.  
White mulberry is native to northern China and is the food of silkworms. It was introduced into the United States in colonial times during an attempt to establish a silk industry and is widely cultivated and naturalized elsewhere.

The fruit of trees grown wild in areas other than China is deep purple, but in cultivated plants it varies from white to pink. The white mulberry is sweet but bland, unlike the more intense flavor of the red mulberry and black mulberry. The red and black variety are best for culinary use, while the white is used medicinally.

In China, mulberry leaves have been treasured as an herbal medicine since ancient times. China’s oldest book of remedies, “Huang Di Ba Shi Yi Nan Jing” , a book devoted to Chinese Medical Practice which is the bible for all herbal medicine, records the plant’s first use.

In Chinese traditional medicine, mulberry has been used as a "cooling" herb to remove excessive heats and toxins from the body. However, it was not until recent years that it started gaining attention by doctors and scientists for its promising blood sugar management properties. Studies have shown, among other things, that alkaloids and N-containing sugars isolated from mulberry leaves are potent inhibitors of alpha glucosidase, a key enzyme in carbohydrate and sugar metabolism pathways.

A recent “Dr. Oz Show” included a segment featuring white mulberry leaf tea and its ability to prevent blood sugar spikes and inhibit sugar digestion.  While this is news to most of us, clinical studies have been on-going for decades.

Andrew Weil, M.D, a widely-respected physician who has devoted the past thirty years to developing, practicing, and teaching others about the principles of integrative medicine, has also recommended the use of white mulberry since at least 2007.

Dr. Weil acknowledges that mulberry leaf has been traditionally used to treat diabetes by numerous cultures around the world and that evidence from human studies show that it significantly reduces the rise in blood sugar that occurs after a meal. He recommends a 6-oz cup of mulberry leaf tea before each meal of the day.

How does it work?

There are some chemicals in white mulberry that work in a similar way to some medicines used for Type 2 diabetes. They slow the breakdown of sugars in the gut so that they are absorbed more slowly into the blood. This helps the body keep blood sugar levels in the desirable range. The Journal of Agricultural and Food Chemistry has reported that mulberry leaves may help prevent diabetes in otherwise healthy adults by suppressing the rise in blood glucose levels and insulin secretion after meals.

Major clinical trials conducted by a team of researchers and doctors at the University of Minnesota (Minneapolis VA Hospital), demonstrate that mulberry leaf can help stabilize blood sugar levels and inhibit carbohydrate absorption in Type 2 diabetics by providing additional support which enables them to make better dietary and lifestyle choices. In these studies, using mulberry leaf was shown conclusively to reduce body's absorption of sugars and other carbohydrates and to lower post-meal blood sugar spikes and stabilize blood sugar levels

One of these studies published in Diabetes Care, the most widely read diabetes journal, reported an average 44% reduction in peak post-meal blood sugar elevations (or spikes). 

Active Ingredients in Mulberry Leaves and Berries

The leaves contain a powerhouse of highly active ingredients and beneficial minerals, such as beta-carotene, GABA-1, amino acids, carotenoids, flavonoids, chlorophyll, vitamin C, B1, B2, B6, A and they are rich in fiber.

The leaves contain six times more calcium than green tea, 25 times more than milk and 40 times more than cabbage. With respect to iron it contains 2.5 times more than green tea and 10 times more than spinach.

The ingestion ratio of the leaves’ fiber is 8 soluble to 45 insoluble. Furthermore, in 100g of mulberry dried leaves you can find 230mg of gamma-amino acid, which is believed to lower blood pressure. 100g of the leaves also contains 46mg of sitosterol which controls the absorption of cholesterol in the intestines, while the same amount of green tea provides 14mg of sitosterol.

The nutritional benefits of dried white mulberries are also impressive: an ounce of berries contains 16 percent of recommended daily fiber, 3 grams of protein, 130% of daily vitamin C, 20%  of iron and is just 90 calories. It’s also high in resveratrol, a proven antioxidant found in red wine.

What Is DNJ (1-Deoxynojirimycin)?

Of particularly interest is an ingredient called 1-deoxynojirimycin (DNJ) which can only be found in mulberry leaves. The chemical structure of 1-deoxynojirimycin is very similar to glucose. If the oxygen portion in the chemical structure of glucose were to be replaced with nitrogen, the composition would be exactly the same as the chemical makeup of DNJ. For this reason DNJ inhibits disaccharides (alpha-glucosidase) and can reduce the intestinal absorption of the amount in the body essentially helping to stabilize the level of sugar in the blood.

Simply speaking,  the intake of disaccharides, (alpha-glucosidase / sugar) is immediately dissolved and broken down and absorbed by the body. But if DNJ is introduced into the body and because of its similarities to glucose, the DNJ preferentially gets absorbed. During the process, the excess glucose moves to the colon without being broken down into monosaccharide and does not get absorbed into the blood. Instead it gets discharged. In effect this maximizes the body’s absorption of any remaining nutrition because disaccharides tend to displace or inhibit the body’s ability to absorb needed nutrients. This is why mulberry leaves, particularly the substrate DNJ, is now highly recognized as a promising herb which may help control carbohydrate absorption.       

Another “Super Food”? Yes!

New data from the U.S. Centers for Disease Control and Prevention (CDC) estimates that the prevalence of diabetes in America is growing at an alarming rate with 24 million people in the U.S. who are now living with diabetes versus 21 million only two years ago. That means nearly 8% of the U.S. population has diabetes, and approximately 90% of those patients have Type 2 diabetes, greatly linked with obesity, poor diet and a lack of exercise, experts say:

"What is so exciting and promising about the current research is that it shows the mulberry leaf, a simple natural ingredient derived from a tree, can nutritionally help improve the blood sugar levels in Type 2 diabetics who struggle every day to follow a balanced diet and maintain a healthy weight, which is essential for managing Type 2 diabetes. Maintaining stable blood glucose levels around meals is especially important for helping those Type 2 diabetics who are trying to make the right dietary and lifestyle choices to manage their health (or wellness). More and more studies have shown that controlling the blood sugar fluctuations (highs and lows) before and after meals is essential for helping those diagnosed with Type 2 diabetes. Maintaining normal blood sugar levels through nutritional support is vital for those who are trying to manage their blood sugar levels primarily through diet and exercise."

Note:

The health benefits of mulberry leaf  vary greatly with differences in extraction methods. Research shows that some extracts have basically no effects on blood glucose, while others are comparable to some pharmaceuticals.
Sugar Controller Tea with Mulberry Leaf has shown consistent, reliable results in those who drink the tea in addition to a maintaining a healthful lifestyle.

White mulberry has been shown to lower blood sugar levels in people with diabetes. Watch for signs of low blood sugar (hypoglycemia) and monitor your blood sugar carefully if you have diabetes and use white mulberry. It is recommend that you speak with your medical advisor before integrating mulberry extract or any other supplement into your existing treatment plan.