The Effect of Turmeric on Diabetes

Turmeric is a golden yellow spice that has been widely used for its medicinal properties. It contains a polyphenol called curcumin that has antioxidant and anti-inflammatory effects.

While research is ongoing, recent evidence suggests curcurmin can be used to prevent and manage type 2 diabetes, a chronic condition characterized by decreased secretion of insulin.

Insulin is a hormone that pulls glucose (sugar) from the bloodstream into cells to be used for energy. When there isn't enough insulin to do that, it causes an ongoing state of elevated blood sugar, also known as hyperglycemia, and results in metabolic disruption and inflammation.

bowl of turmeric powder

Westend61 / Getty Images

Benefits of Turmeric for Diabetes

Regulating Lipid Metabolism 

Metabolic syndrome refers to a group of conditions characterized by altered metabolic processes that are associated with a higher risk of type 2 diabetes. Metabolic syndrome includes insulin resistance, high blood sugar, high blood pressure, low high-density lipoprotein (HDL) cholesterol, high low-density lipoprotein (LDL) cholesterol, increased triglyceride levels, and obesity.

Curcumin can help regulate lipid metabolism in people with diabetes by altering the activity of enzymes involved in metabolic processes to lower the levels of triglycerides and cholesterol in the blood.

A systematic review and meta-analysis of several randomized control trials found that turmeric can potentially lower levels of blood triglycerides by an average of 19.1 mg/dL, total cholesterol by an average of 11.4 mg/dL, and LDL cholesterol by an average of 9.83 mg/dL. However, more research is needed to confirm these suggested effects.

Curcumin can also have beneficial effects in reducing other symptoms of metabolic syndrome by decreasing insulin resistance through improving insulin sensitivity, suppressing the production of new fat cells, and lowering blood pressure.

Oxidative Stress

Clinical research suggests that curcumin can improve markers of oxidative stress throughout the body by increasing levels of certain protective antioxidants like superoxide dismutase.

Curcurmin can also increase the activation of enzymes, like lipid peroxides and glutathione peroxidase, that break down harmful free radicals. Free radicals such as reactive oxygen and nitrogen species are unstable molecules that can cause widespread cell damage throughout the body.

Inflammation 

Inflammation underlies many chronic conditions, including diabetes, and increases oxidative stress and complications. Increased oxidative stress can also cause free radicals to turn on cell signaling pathways that increase the activation of inflammatory responses throughout the body, resulting in a chronic cycle of inflammation.

Tumor necrosis factor is an inflammatory protein that becomes elevated with inflammatory conditions like obesity, diabetes, and metabolic syndrome. Tumor necrosis factor becomes activated in the presence of high blood sugar that occurs with diabetes.

Recent studies suggest that curcumin can block this activation, which helps reduce inflammation in the body. A randomized controlled trial found that supplementation of one gram of curcumin per day for eight weeks helped lower levels of tumor necrosis factor by an average of 16.22 pg/mL in women with metabolic syndrome.

Effect of Specific Organ Systems As They Relate To Diabetes

Liver Disorders

It is common for patients with diabetes to have fatty liver disease or other liver disorders. Research suggests that curcumin can help regulate liver enzymes that control the levels of lipids and glucose due to its anti-inflammatory properties.

A meta-analysis of four randomized controlled trials found that daily supplementation of curcumin of one gram or more for eight weeks reduced levels of alanine aminotransferase by an average of 11.36 IU/L and reduced levels of aspartate aminotransferase by an average of 9.22 IU/L.

Adipose Tissue Dysfunction

Diabetes is often associated with dysfunction of adipose, or fat tissue, which controls the levels of glucose throughout the body. Adiponectin is a hormone primarily found in fat tissue that regulates blood sugar levels and the breakdown of fatty acids. In type 2 diabetes, secretion of adiponectin is disrupted and reduced due to high blood sugar levels.

Curcumin can benefit adipose tissue dysregulation by regulating the secretion of adiponectin. Curcumin has the potential to help decrease inflammatory markers, such as tumor necrosis factor and nitric oxide, that cause irregular accumulation and activation of macrophages (specialized cells involved in the detection and destruction of bacteria and other harmful organisms) within adipose tissue, which disrupt the secretion of adiponectin.

Diabetic Neuropathy

Diabetic neuropathy is a common symptom of diabetes characterized by injury to peripheral nerves that transmit signals to and from the arms and legs. Diabetic neuropathy results from injury to blood vessels that supply the nerves of the arms and legs. This is caused by widespread inflammation resulting from disrupted blood sugar levels.

Elevated levels of inflammatory proteins called advanced glycation end products (AGEs) become altered by the presence of excess blood sugar and cause oxidative stress and chronic inflammation in diabetic neuropathy. Curcumin contains both phenols and flavonoids that can scavenge free radicals and slow the oxidative damage that occurs. Curcumin can also increase the activation of antioxidant enzymes, such as superoxide dismutase, to further combat free radicals.

Diabetic Nephropathy

Diabetic nephropathy, also called diabetic kidney disease, affects the kidney's ability to filter and remove waste and fluid from the body. It is characterized by the presence of albumin in the urine, increased arterial blood pressure, and a decreased glomerular filtration rate, an indicator of proper kidney functioning.

Curcumin can help manage diabetic nephropathy by promoting the clearance of creatine and urea from the body, decreasing the levels of albumin and enzymes in the urine, and regulating the activity of kidney enzymes.

Diabetic Vascular Disease

Vascular disease as a result of diabetes occurs from damage to both small and large blood vessels throughout the body caused by widespread inflammation. Studies suggest that curcumin can help reduce complications from diabetic vascular disease in a variety of different ways.

These include suppressing accumulation of inflammatory AGE proteins and inhibiting activation of certain cells that promote oxidative stress and cell damage. Curcumin can also improve wound healing and formation of new blood vessels and reduce tumor necrosis factor that causes excessive contraction of blood vessels.

Other Diabetes-Associated Complications

Use of curcumin may also be beneficial for reducing other complications of type 2 diabetes, including musculoskeletal diseases by suppressing bone resorption and reducing enzymes that break down bone. Curcumin also helps skeletal muscles increase glucose uptake to reduce insulin resistance.

Curcumin may also help reduce other complications associated with type 2 diabetes like erectile dysfunction and gastroparesis, a condition caused by delayed emptying of stomach contents, by decreasing levels of inflammation and oxidative stress.

Turmeric Challenges

Bioavailability

Bioavailability refers to the amount of a substance that can be absorbed that reaches the bloodstream for systemic circulation. Substances delivered directly into a vein through an IV have the highest bioavailability, but when substances are taken by mouth, their bioavailability decreases as they are digested and absorbed through the intestines.

Taking curcumin by mouth does not necessarily mean someone can get its beneficial effects because curcumin has poor bioavailability due to poor absorption through the intestines, rapid metabolism (it is broken down very quickly), and rapid elimination, where it is excreted from the body before it can exert its positive effects.

Research suggests that these issues of absorption, metabolism, and elimination can be reduced by consuming curcumin with piperine, a chemical compound found in black pepper. When combined with piperine, the bioavailability of curcumin can increase by as much as 2,000%, significantly increasing its effects.

Side Effects

Curcumin has been approved by the Food and Drug Administration (FDA) with a label of “Generally Recognized As Safe” due to good tolerability, safety, and efficacy, including dosages between 4,000 and 8,000 mg/day. While curcumin is generally considered safe to use, some negative side effects, including headache, nausea, diarrhea, rash, and yellow stool, have been reported.

Curcumin may also have potential interactions with certain medications such as blood thinners (anticoagulants), antibiotics, antidepressants, cardiovascular medications, and cancer drugs.

A Word From Verywell

Turmeric should not replace other treatment plans for diabetes prescribed by your doctor. Always make sure to ask your doctor about taking turmeric or any other forms of treatment or dietary supplements to ensure it is safe for you and will not interact with any medications you are taking. Any changes to your treatment regimen for managing diabetes should always be discussed with a healthcare professional, such as your primary care provider or endocrinologist.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Pivari F, Mingione A, Brasacchio C, Soldati L. Curcumin and type 2 diabetes mellitus: prevention and treatment. Nutrients. 2019;11(8):1837. doi: 10.3390/nu11081837

  2. Hewlings SJ, Kalman DS. Curcumin: a review of its effects on human health. Foods. 2017 Oct 22;6(10):92. doi:10.3390/foods6100092

  3. Yuan F, Dong H, Gong J, et al. A systematic review and meta-analysis of randomized controlled trials on the effects of turmeric and curcuminoids on blood lipids in adults with metabolic diseasesAdv Nutr. 2019;10(5):791-802. doi:10.1093/advances/nmz021

  4. Panahi Y, Hosseini MS, Khalili N, Naimi E, Simental-Mendía LE, Majeed M, Sahebkar A. Effects of curcumin on serum cytokine concentrations in subjects with metabolic syndrome: A post-hoc analysis of a randomized controlled trial. Biomed Pharmacother. 2016;82:578-82. doi: 10.1016/j.biopha.2016.05.037

  5. Mansour-Ghanaei F, Pourmasoumi M, Hadi A, Joukar F. Efficacy of curcumin/turmeric on liver enzymes in patients with non-alcoholic fatty liver disease: A systematic review of randomized controlled trials. Integr Med Res. 2019;8(1):57-61. doi:10.1016/j.imr.2018.07.004

  6. Zhang DW, Fu M, Gao SH, Liu JL. Curcumin and diabetes: a systematic review. Evid Based Complement Alternat Med. 2013;2013:636053. doi:10.1155/2013/636053

  7. Grover M, Shah K, Khullar G, Gupta J, Behl T. Investigation of the utility of Curcuma caesia in the treatment of diabetic neuropathy. J Pharm Pharmacol. 2019;71(5):725-732. doi: 10.1111/jphp.13075. 

By Kristen Gasnick, PT, DPT
Kristen Gasnick, PT, DPT, is a medical writer and a physical therapist at Holy Name Medical Center in New Jersey.