As a person struggling with CF-related diabetes, I've tried lots of things to balance my blood sugar over the years. It wasn't until 2020 when I discovered the ketogenic diet that my life really changed for the better and my blood sugar came under excellent control. Diet is the primary intervention for controlling most types of diabetes, but sometimes we may need medications and/or herbal medicines to assist with glucose control.
I recently taught an in-depth class on holistic nutrition and herbal medicine for diabetes and blood sugar imbalances including CFRD, types I and II diabetes, metabolic syndrome, reactive hypoglycemia, and glucose intolerance (which you can check out here). I cover the topics of diet and herbs very comprehensively in that class, but in this article I'll mention briefly a few medicinal herbs that I have used and recommended to other diabetics to assist with blood sugar control.
First, a disclaimer: the information here is not meant to replace medical advice from your medical provider. If you're using insulin or glucose-lowering drugs it is wise to consult a qualified herbalist or other healthcare practitioner to check on potential herb-drug interactions.
Now that that's out of the way, let's talk about a few herbs.
Stevia is a plant native to Brazil and Paraguay that contains a glycoside of the diterpene steviol, which is 30-320 times sweeter than sugar. But because cannot be broken down by the human digestive system into glucose or other monosaccharides, it does not raise the blood sugar. It is my only sweetener and I add it to my morning tea every day. Studies have shown it to reduce blood sugar and provide antioxidant effects. The leaf is used and it's very easy to grow in your garden as an annual. One plant provided me with enough for a full year because the dose of leaf powder that I add to my tea is very small (about 1/8-1/3 tsp) because it's so powerfully sweet! I recommend only using the whole powdered leaf, not the extract, because the extracts sold on supermarket shelves are primarily erythritol, a sugar alcohol derived from corn. You can tell if the stevia powder if from the whole leaf if it is green in color. Fake stevia powder (erythritol) is white. You can get this powder from your local apothecary or Railyard Apothecary. When first starting to use stevia, start with a very small dose. When I first started to use it I thought the taste was similar to artificial sweetener, but eventually I got used to it. Too much can taste yucky.
Bitter melon, Momordica charantia, is a melon used in traditional cuisines all over the world, especially in East Asian cooking. There are tons of studies showing it to be very effective at improving diabetes and blood sugar control. It's taste is very bitter (hence the name) and it works by inhibiting glucose absorption and promoting glucose utilization in the liver. Doesn’t seem to increase overall insulin levels produced by the pancreas though, which is important in the case of insulin resistance (because the more insulin we produce, the more resistant our cells become to it in the case of type II diabetes or metabolic syndrome). It contains an insulin-like polypeptide which can reduce blood sugar. It's not for use in pregnancy or children. Be careful if you're using metformin, because it may work similarly to metformin in improving insulin sensitivity. It may be used to replace metformin, but consult a practitioner on this to make the switch safely in order to prevent hypoglycemia. It may not be appropriate for people experiencing frequent hypoglycemia. Bitter melon would be most appropriate for people with type 2 diabetes, metabolic syndrome, or others with insulin resistance. Although you certainly can cook with it or drink the juice, the easiest way to ingest it is in capsules. The dose of the whole powder is 3-15g, starting with a low dose. The standardized extract in capsules is 100-200mg 3xday. If using juice the dose is 1-2 oz per day.
Gymnema sylvestre is from India and its common name means “the sugar destroyer”.
When the tincture (alcohol extract) is taken on the tongue it changes the taste buds that receive the sweet taste and deactivates them which makes sweet stuff taste really weird and a bit like cardboard. This may help us when trying to quit our sugar addictions. The effect on the tongue can last for several hours. There has been a lot of research on this herb and studies have shown that when taken in capsules it can improve fasting blood sugar, raise insulin levels, and lower A1c. Studies have shown it to be very effective for improving type 2 diabetes. Gymnema may be best to use for type 2 diabetics who are taking insulin, but be careful to adjust doses of medications in accordance with reduced need for them (consult a practitioner). The typical dose of capsules is 500mg twice a day before meals. The tincture dose is 1 mL, hold in the mouth for 30 seconds. It can help curb carbohydrate cravings.
Cinnamon (Cinnamomum verum – true/Ceylon cinnamon) is safe for almost everyone people. Like other culinary spices it is anti-inflammatory and sensitizes us to insulin. It has mucilage which slows the rate of glucose absorption and also has been shown to inhibit enzymatic breakdown of carbohydrates into glucose. Cinnamon can be great to cook with and add to foods, tea, or coffee. I used to use cinnamon regularly with every carbohydrate-containing meal. Capsule dose is typically 500-1000 mg per meal/snack as needed. Start low and work up. Be extra careful if you're a person who experiences reactive hypoglycemia (though if used at the right times it may help prevent it).
While the above herbs work primarily by improving insulin sensitivity, flaxseeds work to reduce blood sugar primarily by adding fiber and mucilage to meals which slows the rate of glucose absorption into the blood. They also provide anti-inflammatory omega-3 fatty acids (ALA) which can sensitize us to insulin by reducing systemic inflammation. Adding 1 tbsp of flax seed powder to liquidy meals like oatmeal or soups can lower their glycemic index. They have been show to lower blood triglycerides as well.
There are many more herbs that can help us control our blood sugar, but these are just a few that are common enough and easy to get ahold of. If you want to learn about more medicinal herbs for diabetes including adaptogens and nervines, please purchase my two-hour comprehensive class here.
Be well. :)
Mica McDonald (they/he) is a clinical herbalist, nutritionist, ecologist, and writer living in Abenaki territory (Vermont).