FACT CHECK: Do clove and cinnamon improve insulin sensitivity?

CLAIM:

Eating a mixture of clove and cinnamon may improve insulin sensitivity, help regulate blood sugar levels, and reduce glucose spikes after meals. The claim also suggests that compounds in these spices can mimic insulin action, support pancreatic health, and reduce inflammation linked to metabolic disorders. 

FACT:

Current research suggests cinnamon and clove may have compounds that modestly influence blood sugar regulation and metabolic health in some cases. However, scientific evidence remains mixed and limited, with several studies showing little or no significant improvement in insulin sensitivity, especially in humans. Experts say these spices may offer mild antioxidant or metabolic benefits but should not be considered substitutes for diabetes treatment, exercise, weight management, or other medically proven ways to improve insulin resistance.

In a recent Instagram post by the page ‘lijiwellness’, which has over 5.31 lakh followers, claims surrounding clove and cinnamon improving insulin sensitivity have sparked discussion online. The post mentions that, “Study found mixing clove and cinnamon will help improve insulin sensitivity.”

The caption of the post further describes the spice combination as “Metabolic Harmony: Clove & Cinnamon” and questions whether the “aromatic spice duo” could be “the secret to balancing your blood sugar and improving insulin response.” It claims that both spices contain compounds that “mimic insulin and help move glucose into your cells more efficiently,” while also suggesting that adding the mix to meals may help reduce blood sugar spikes after eating.

According to the post, the spices are also “rich in polyphenols that protect the pancreas and support metabolic longevity” and may provide “inflammation support” by reducing systemic inflammation linked to hormone signalling. The caption concludes by calling the blend “a simple, flavorful way to support your metabolism with every bite,” encouraging users to add it to “morning oats or tea.”

Do clove and cinnamon improve insulin sensitivity? 

Current research suggests that cinnamon and clove may have compounds capable of influencing blood sugar regulation and metabolic health in certain settings. However, evidence remains inconsistent, many studies are small or short-term, and effects appear to vary depending on dosage, preparation, health status, and whether supplements or extracts are used. Scientists also emphasise that these spices should not be viewed as substitutes for medical treatment for diabetes or insulin resistance.

A widely cited 2010 review examined cinnamon’s potential role in metabolic health and noted that metabolic syndrome is associated with “insulin resistance, elevated glucose and lipids, inflammation, decreased antioxidant activity, increased weight gain, and increased glycation of proteins.” According to the review, cinnamon had shown beneficial effects across “in vitro, animal, and/or human studies.” The authors stated that human studies involving individuals with metabolic syndrome, type 2 diabetes, and polycystic ovary syndrome had reported improvements in “glucose, insulin, insulin sensitivity, lipids, antioxidant status, blood pressure, lean body mass, and gastric emptying.”

However, the review also stressed that findings across studies were inconsistent. It noted that “not all studies have shown positive effects of cinnamon,” adding that factors such as the “type and amount of cinnamon,” along with participants’ health conditions and medications, could influence outcomes.

Subsequent clinical trials produced similarly mixed results. A 2014 randomised study involving 21 individuals with impaired glucose tolerance investigated whether consuming capsules equivalent to 6 g of cinnamon twice daily for 12 weeks could improve insulin sensitivity. Researchers found that “the ingestion of 6 g C. cassia twice a day for 12 weeks had no significant effect on insulin sensitivity, HbA1c, fasting glucose or BMI.” The study ultimately concluded that cinnamon supplementation “did not change the insulin sensitivity” in subjects with impaired glucose tolerance.

Another 2015 study explored whether Cassia cinnamon affected glucose handling in young, sedentary, obese women. Researchers observed that a 5 g dose of cinnamon lowered the peak blood glucose response during an oral glucose tolerance test at the 30-minute mark. However, the study found “no improvement in IS and IR,” referring to insulin sensitivity and insulin resistance. The researchers concluded that while cinnamon “may reduce the peak BG response and improve glucose tolerance,” it did not significantly improve insulin sensitivity.

Some later studies reported more promising outcomes, particularly among people with type 2 diabetes. A 2018 clinical trial involving 140 patients with type 2 diabetes found that cinnamon supplementation improved several metabolic markers, including “fasting insulin and insulin resistance,” along with fasting glucose, HbA1c, and lipid levels. Researchers also noted that these benefits were “significantly more prominent” among participants with higher BMI.

At the same time, evidence regarding cinnamon’s anti-inflammatory effects has remained uncertain. A 2020 randomised controlled trial involving adults with type 2 diabetes examined whether cinnamon supplementation affected inflammatory markers such as hs-CRP, IL-6, TNF-α, NF-kB, and SIRT1. The study reported that cinnamon had “no beneficial effects” on most of these inflammatory markers, despite some isolated differences observed in NF-kB levels.

More recent research has continued exploring cinnamon’s effects on blood sugar regulation. A 2024 trial involving participants with obesity-related prediabetes found that cinnamon supplementation was associated with lower 24-hour glucose concentrations and reduced glucose peaks compared to placebo. Researchers concluded that cinnamon “may contribute to better glucose control when added to the diet in people who have obesity-related prediabetes.” However, the study focused on controlled supplementation and did not establish cinnamon as a standalone treatment for insulin resistance.

When it comes to cloves, much of the evidence remains preliminary, though some studies suggest possible metabolic benefits. A 2017 laboratory and animal study examined clove extract and one of its active compounds, nigricin. Researchers reported that clove extract “decreases free fatty acid-mediated insulin resistance in mouse myoblasts” and improved glucose tolerance and insulin signalling in diabetic mice. The study concluded that clove extract and nigricin “can be potential therapeutic agents for alleviating insulin resistance.” However, these findings were based primarily on cell and animal models rather than large-scale human trials.

Human research on cloves has also produced early but limited findings. A 2019 study involving 13 volunteers examined the effects of polyphenol-rich clove extract supplementation for 30 days. Researchers observed reductions in postprandial blood glucose levels and found that the extract enhanced glucose uptake in cell-based experiments. The study concluded that the findings “underscore the therapeutic utility” of clove extract for maintaining healthy glucose metabolism, while also emphasising the need for “larger-scale clinical trials.”

Similarly, a 2022 randomised double-blind study investigating a clove polyphenol extract called Clovinol in adults with metabolic syndrome reported improvements in fasting blood sugar, HbA1c, insulin resistance, cholesterol levels, and antioxidant markers. Researchers stated that Clovinol “may be a safe and relatively simple cost affordable approach for metabolic syndrome” and noted reductions in inflammatory markers such as IL-1β and TNF-α. However, the study focused on a specific standardised extract rather than everyday dietary use of cloves.

What experts say

Dr Rajiv Kovil, Head of Diabetology and Weight Loss Expert at Zandra Healthcare, said the claim that clove and cinnamon “mimic insulin” is highly misleading and oversimplifies how insulin actually works in the human body. According to him, while spices like cinnamon and clove may contain antioxidant compounds and could offer minor metabolic benefits, there is no strong human evidence proving that they act like insulin or reverse insulin resistance.

“I think that all this ‘mimicking insulin’ itself is a very misleading phrase,” Dr Kovil said. He explained that biologically, the statement implies that these substances work in the same way as insulin inside the body, “and there is absolutely no human data to suggest that.”

He further noted that cinnamon has shown “a little bit of data” in some metabolic studies, whereas for clove, “there is nothing as such.” According to him, both ingredients are “good kitchen spices” with antioxidant properties, but “not anti-diabetic medicine.” He added that claims suggesting they can dramatically improve insulin resistance are “very, very exaggerated.”

Explaining the science behind insulin sensitivity, Dr Kovil said the process is far more complex than social media posts often suggest. “It’s not like something is opening the door and you are getting in,” he said, referring to the claim that glucose is simply “pushed” into cells. “It’s a whole signalling pathway where multiple hormones are acting on multiple pathways.”

Dr Kovil also stressed that no single “superfood” has been scientifically proven to significantly improve insulin sensitivity on its own. Instead, he pointed to lifestyle interventions as the most effective approach. “Exercise is the best, and weight loss,” he said. He added that “better sleep, stress correction, reducing ultra-processed foods, good aerobic activity, and healthy sleep cycles” are the factors that genuinely help improve insulin sensitivity in humans.

While certain micronutrients such as chromium and zinc have shown some evidence in metabolic research, Dr Kovil said that claims around spice “additives” dramatically improving insulin resistance should be interpreted cautiously.

Agreeing to this, Dr Narendra BS, Lead Consultant – Endocrinology & Diabetology at Aster Whitefield Hospital, said that while some studies suggest cinnamon and clove may offer modest benefits for blood sugar regulation and insulin sensitivity, the evidence remains mixed and not strong enough to support sweeping social media claims.

According to him, cinnamon has shown “some mild improvements” in fasting blood sugar and insulin response in certain studies, while evidence for clove in humans is still limited. He also clarified that the phrase “mimic insulin” can be misleading. “Some plant compounds may influence insulin signalling pathways, but that does not mean these spices work like insulin medication or replace the hormone produced by the pancreas,” he said.

Dr Narendra further noted that many positive findings come from laboratory or animal studies, whereas human trials have shown inconsistent results. He stressed that the effects of using cinnamon or clove in normal dietary amounts are generally mild and should not replace medical care, lifestyle changes, exercise, weight management, or diabetes medication.

This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS