5 Herbs for Blood-Sugar Balance
The Science Behind the Power of Plants
Nutrients known to support healthy blood-sugar regulation include B vitamins, alpha lipoic acid (ALA), chromium, magnesium, vanadium, and zinc.* Many of these can be supplied in a multivitamin and mineral formula. Plant compounds, such as berberine and myricetin, also support healthy glucose metabolism.*
Another way to support healthy blood-sugar is with herbal preparations. Traditional cultures worldwide have relied on herbs for centuries to support energy, metabolism, and overall health. But how much has modern science been able to support the traditional uses of herbs for blood-sugar balance?
From cell cultures to clinical trials, here’s a look at the published research examining the use of banaba leaf, bitter melon, fenugreek, ginseng, and gymnema to support blood-sugar balance.*
Banaba (Lagerstroemia speciosa L.) is a species of crepe myrtle tree native to Southeast Asia. The banaba plant grows more than 30 feet tall, producing delicate pink and lavender flowers in the spring. Its leaves, which can be up to seven inches long, are commonly used in the Philippines, Taiwan, and Japan to make tea and also dietary supplements.
Banaba leaf extracts often contain a standardized amount of corosolic acid—a compound that has been isolated and evaluated in cell-culture and animal studies. These studies suggest that corosolic acid supports cellular uptake of glucose, healthy insulin function, and antioxidant defense systems.*
Banaba leaves also contain ellagitannins. These compounds haven’t been studied as extensively as corosolic acid, but might offer synergistic support for blood-sugar regulation and metabolic health.*
The most widely cited study of banaba is a 2003 randomized trial of banaba leaf extract, standardized to 1 percent corosolic acid. The product (both 32 mg and 48 mg per day for two weeks) demonstrated a significant ability to support healthy blood-sugar.*
Bitter melon (Momordica charantia) is a vegetable commonly eaten in China, India, Thailand, East Africa, and other parts of the subtropical world, and also known as bitter gourd, balsam pear, or karela. Dietary supplements can be prepared from the fruit, skin, stem, leaves, or skin of the plant.
More than 200 different plant compounds have been isolated from bitter melon. Some of these, including charatin, polypeptide-p, vicine, and momordin, have been shown in laboratory studies to support healthy blood-sugar metabolism.*
Polypeptide-p has a chemical structure that closely resembles bovine insulin, and is therefore commonly referred to as “plant insulin.” Despite this intriguing fact, however, oral consumption of polypeptide-p has never been evaluated in a human clinical trial.
But over the last several decades, there have been numerous human studies evaluating bitter melon in the context of blood-sugar regulation and metabolic health. Although many of these studies have been small, and only a few have been randomized and controlled, most suggest that bitter melon supports healthy blood-sugar and metabolic health.*
One thread that’s consistent throughout the studies is that higher intakes of bitter melon yield more dramatic results. In a four-week randomized, controlled trial, 2,000 mg of bitter melon per day supported healthy blood-sugar balance.* However, taking 500 mg or 1,000 mg per day didn’t have the same effect. And in another study, daily intakes of both 2,000 mg and 4,000 mg supported healthy glucose metabolism. *
There may also be individual differences in how people respond to bitter melon. A study published in 2017 that evaluated the short-term effects of consuming a bitter melon drink found that it supported healthy blood-sugar regulation in only 50 percent of participants. The specifics of why some people might benefit from bitter melon while others may not has not been evaluated.
Fenugreek (Trigonella foenum-graecum) seeds are widely used in cooking and are traditionally used to support digestive and metabolic health.* Dietary supplements can be made with whole ground fenugreek seeds or standardized extracts that concentrate specific plant compounds.
The most extensively studied fenugreek compounds are diosgenin, 4-hydroxyisoleucine (4-OH-Ile), and the fiber component of the plant. Studies show that diosgenin supports the health of pancreatic beta cells, along with healthy hepatic glucose metabolism and liver health. 4-OH-Ile is a branched-chain amino acid that supports healthy insulin secretion. And fenugreek’s soluble fiber supports gastrointestinal motility, digestive enzymes, and other aspects of digestive health.*
A meta-analysis of 10 randomized, controlled trials of fenugreek was published in 2014. Study sizes ranged from five to 69 participants; intakes of fenugreek ranged from 1 gram to 100 grams per day; and study durations ranged from 10 to 84 days. Fenugreek was given as a seed powder, an alcohol extract of the seeds, or as an ingredient in bread. The meta-analysis concluded that fenugreek supports healthy blood-sugar regulation, but only when taken in amounts equal to or greater than 5 grams per day.*
Since the publication of that meta-analysis, an additional randomized, controlled trial of fenugreek was released. It involved 140 people who were given 5 grams twice a day of fenugreek, or a placebo, for three years. The study found that fenugreek had a significant ability to support blood-sugar regulation and metabolic health.*
Gymnema (Gymnema sylvestre) is an herb native to India, Africa, and Australia, where it has a long history of traditional use for supporting metabolic health.* The leaves of the plant are used to make tea, tinctures, and powders for dietary supplements. Gymnema is commercially available as a whole plant extract or as an extract that’s standardized to the gymnemic acid content—the compound that’s attracted the most scientific interest.
Gymnemic acid’s chemical structure is enough like glucose that it interacts with glucose receptors in the mouth—blocking the sensation of sweetness. Swallowing a capsule of gymnemic acid won’t achieve this result—but swishing tincture or tea in the mouth will. The numbing of the sweet taste receptors can be invaluable for people who are trying to significantly reducing their sugar intake and manage sugar cravings.
Gymnemic acid has also been shown, in animal and cell-line studies, to delay absorption of glucose from the digestive tract, support the healthy normal release of insulin from the pancreas, and support healthy cellular metabolism of glucose.*
The bulk of published research on gymnema comes from animal studies. One of the few clinical trials of gymnema extract found that 600 mg per day supported healthy body weight, but didn’t affect insulin function. While this herb is prized by many clinicians to support blood-sugar regulation, most of its evidence comes from traditional wisdom and experience.
There are 11 commercially available species of ginseng, including American ginseng (Panax quinquefolius L) and Korean ginseng (Panax ginseng). Several of these species have been studied in the context of glucose metabolism and metabolic health.
Ginseng’s unique compounds include more than 150 ginsenosides. These compounds are thought to underlie the ability of ginseng to support healthy glucose and insulin balance.* Ginsenosides concentrate in the root, which is the part most often used in herbal preparations.
A meta-analysis of eight studies of ginseng was published in 2016. All studies were randomized, double-blind, placebo-controlled trials. The number of participants in each study ranged from five to 43. Duration of studies ranged from four to 20 weeks. The combined analysis from these studies concluded that ginseng supports healthy glucose and insulin metabolism.* It’s interesting to note that the benefits of ginseng were only seen in study participants who weren’t taking medications.
It’s not clear which type of ginseng is most useful in supporting metabolic health. The 2016 meta-analysis included studies of American ginseng, fermented red ginseng, hydrolyzed ginseng extract, Korean red ginseng, Ginsam, renshen jianxin capsules, and Panax quinquefolius saponin.
FROM TRADITION TO SCIENCE
The traditional use of herbs often involves a combination of multiple botanicals for synergy. Researchers, on the other hand, tend to evaluate the effects of single herbs. But the few studies that have examined herbal combinations show promise for blood-sugar balance.*
Botanical formulations that have been shown in clinical trials to support healthy glucose metabolism include a mixture of mulberry leaf, Korean red ginseng, and banaba leaf, as well as a mixture of bitter melon, jamun seed, and fenugreek.*
So whether you rely on the wisdom of your elders or the data in the medical journals, there is evidence to suggest that traditional botanicals support healthy-blood sugar balance and metabolic health.* But, as always, what’s most important is evaluating each individual patient’s response for improved energy, mood, metabolism, and overall quality of life.
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