Cloves show genuine promise for people with diabetes. Research in both animals and humans suggests that compounds in cloves can lower fasting blood sugar, reduce insulin resistance, and improve long-term blood sugar markers like HbA1c. That said, cloves are a spice, not a medication, and the evidence is still building. Here’s what we know so far about how cloves affect blood sugar and what that means for you practically.
How Cloves Affect Blood Sugar
The main active compound in cloves is eugenol, which makes up roughly 80% of clove oil. Eugenol appears to work on multiple fronts that matter for diabetes. In animal studies, it significantly reduced blood glucose, triglycerides, cholesterol, and markers of inflammation. It also restored insulin levels and replenished the body’s natural antioxidant defenses, both of which tend to be depleted in diabetes.
A randomized, double-blinded human trial using a standardized clove bud polyphenol extract found improvements across several key diabetes markers: fasting blood sugar, post-meal blood sugar, HbA1c (a measure of average blood sugar over roughly three months), insulin levels, and a score called HOMA-IR that reflects how resistant your cells are to insulin. In other words, the extract didn’t just nudge one number. It improved the overall picture of how the body handles sugar.
One reason cloves may help is their effect on oxidative stress. Diabetes creates a vicious cycle where high blood sugar generates harmful molecules called free radicals, which in turn damage cells and worsen insulin resistance. Clove polyphenols boosted the body’s internal antioxidant system by as much as sixfold in the human trial, helping break that cycle.
Benefits Beyond Blood Sugar
High cholesterol and heart disease are among the most dangerous complications of diabetes, and cloves appear to address those risks too. In lab and animal studies, clove extract showed strong activity against several processes that drive heart disease: it blocked the oxidation of LDL cholesterol (the step that makes “bad” cholesterol actually dangerous), reduced the uptake of oxidized LDL by immune cells (a key step in plaque formation), and inhibited a protein involved in cholesterol transport.
In a zebrafish model fed a high-cholesterol diet, a clove extract group saw a 68% drop in serum cholesterol and an 80% drop in triglycerides. The same group gained the least body weight and showed the strongest antioxidant activity. While zebrafish aren’t humans, these are striking numbers that align with the broader pattern seen in other models.
Clove extract also showed potent anti-glycation activity. Glycation is the process where sugar molecules stick to proteins in your blood, eventually forming compounds that damage blood vessels, nerves, and organs. It’s a major driver of diabetic complications like kidney disease and retinopathy. By inhibiting glycation, cloves may help protect against the long-term damage diabetes causes, not just the high blood sugar itself.
How to Use Cloves Safely
The safest way to get cloves into your diet is simply cooking with them. Ground cloves work well in oatmeal, curries, stews, roasted vegetables, and spice blends. A pinch or two added to meals is a reasonable amount. Some people steep whole cloves in hot water to make clove tea, though the amount of active compound you absorb that way is unpredictable.
Clove oil is a different story. It can be toxic in relatively small amounts, with as little as two teaspoons potentially causing serious harm. Concentrated clove oil is not something to experiment with at home, especially if you’re managing diabetes with other medications.
The FDA has not approved any clove extract as a treatment for diabetes or any other condition. The human trial that showed positive results used a standardized polyphenol extract at a controlled dose, which is different from sprinkling cloves on your food. Cooking with cloves is unlikely to produce the same magnitude of effect seen in clinical research, but it contributes beneficial compounds with minimal risk.
Interaction With Diabetes Medications
This is the most important caution. Cloves can lower blood sugar on their own, and if you’re already taking insulin or oral diabetes medications, adding clove supplements could push your blood sugar too low. Hypoglycemia (low blood sugar) causes symptoms like dizziness, shakiness, confusion, and in severe cases, loss of consciousness.
If you use diabetes medication and want to try a clove supplement, monitor your blood sugar more frequently than usual and let your doctor know. Using cloves as a cooking spice in normal culinary amounts is far less likely to cause a problem than taking concentrated capsules or extracts. You should also stop clove supplements before any scheduled surgery, since cloves contain compounds that may slow blood clotting and affect blood sugar control under anesthesia.
What This Means Practically
Cloves aren’t a replacement for your diabetes management plan. But the evidence suggests they’re more than just a flavor. The combination of blood sugar reduction, improved insulin sensitivity, antioxidant protection, and cholesterol-lowering effects makes cloves one of the more promising culinary spices for people with diabetes. Adding them to your cooking is a low-risk way to get some of those benefits. If you’re considering a concentrated supplement, treat it like you would any new addition to your regimen and keep a close eye on your numbers.