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Turmeric is the rhizome of a tall and leafy herb used as a medicinal and culinary spice. Known for its deep golden hue, its use dates back to nearly 4000 years in India. Sanskrit has at least 53 names for turmeric, including names that translate to words and phrases like “lucky,” “one that wins over diseases,” and “capability.”

The most well-known phytochemical in turmeric is a curcuminoid called curcumin. The other major curcuminoids in turmeric are demethoxycurcumin and bisdemethoxycurcumin.  When curcuminoids are degraded, the major end products are phytochemicals like ferulic acid and vanillin. Curcumin also contains vitamins like vitamin E, K, C, and B-complex, as well as minerals like iron, magnesium, manganese, zinc, selenium, calcium, and potassium.

Curcumin is highly pleiotropic with many biological targets, and it has therefore been researched for its role in a wide variety of conditions. Curcumin is perhaps most revered for its powerful anti-inflammatory effects and its ability to reduce inflammatory markers like C-reactive protein (CRP), IL-6, and TNFα. Curcumin and resveratrol, a phytochemical abundant in grapes and peanuts, have a synergistic effect and result in approximately 15% greater antioxidant effect when combined compared to the average of individual effects.

Health Benefits of Turmeric

Arthritis. Osteoarthritis involves several factors including inflammatory and metabolic factors. A systemic review sought to determine the efficacy of turmeric in patients with knee osteoarthritis, and it found that turmeric improved pain and physical function when compared to placebo. Findings also showed that turmeric and non-steroidal anti-inflammatory drugs (NSAID) therapy had similar effectiveness, though an optimal dose for turmeric was not determined. Another review found that turmeric was effective in reducing knee pain and improving physical function. Additionally, turmeric extracts resulted in 12% fewer adverse events compared to NSAIDs.  Curcumin may be synergistic with boswellia (boswellic acids), an herb used in pain management for osteoarthritis.

Curcumin can be useful in the treatment of rheumatoid arthritis, a painful autoimmune arthritis disease. Besides joint swelling, pain, edema, tenderness, redness, and stiffness, those with rheumatoid arthritis may experience joint muscle atrophy and joint deformity in later stages of the disease. A systemic review and meta-analysis of 10 randomized controlled trials concluded that curcumin supplementation reduced clinical symptoms of rheumatic diseases. A 2022 randomized controlled trial investigated the synergistic effects of curcumin with exercise in 90 patients with rheumatoid arthritis over a 24-week period. The first group consumed 180 mg curcumin per day and engaged in three 45-minute strength training sessions per week. The second group was given 180 mg curcumin per day but no exercise regimen. Results showed that the curcumin and exercise group had significantly higher reductions in pain, stiffness, CRP, and rheumatic factors.

Cancer. Curcumin may have anticancer effects against colon, lung, thyroid, and renal cancers, possibly by inhibiting proliferation and inducing apoptosis of cancer cells. Other cancers for which curcumin may have anticancer effects include prostate, gastric, and lung cancers. Because curcumin affects cancer via multiple cell signaling pathways, it may be helpful in avoiding the development of drug resistance, which can occur with some cancer therapies.

Methylation plays a role in the development of virtually all cancers. For example, hypermethylation of tumor suppressor genes can cause a loss of function, while DNA hypomethylation is involved in tumorigenesis. DNA methylation is responsive to environmental factors like diet, and curcumin may modulate dysregulated epigenetic events in cancer cells and prevent cancer in this manner, among others. One study found that treatment of a breast cancer cell line with curcumin for 72 hours reversed hypermethylation and reactivated the tumor suppressor gene glutathione S-transferase pi 1. Curcumin uptake into cells is also shown to be significantly higher in tumor cells, including breast cancer tumor cell lines, compared to normal cells.

Additionally, the antioxidant and anti-inflammatory properties of curcumin prevent the accumulation of reactive oxygen species and free radicals, which are implicated in cancer development. Interestingly, at high concentrations, the prooxidative effects of curcumin can increase reactive oxygen species – which are already higher than normal in cancer cells – and cause oxidative stress-induced cancer cell death, as shown in human gastric cancer cells.

Cardiometabolic Health and Body Composition. A meta-analysis of randomized controlled trials concluded that turmeric and curcumin can improve triglycerides and LDL cholesterol – but not HDL cholesterol – in individuals at risk of cardiovascular disease. The analysis also found a beneficial effect on total cholesterol levels in individuals with metabolic syndrome, suggesting that turmeric and curcumin may be more beneficial in individuals at high risk of cardiovascular morbidity. Another analysis of randomized controlled trials found that curcumin or turmeric supplementation is shown to significantly improve anthropometric measures of obesity, such as body weight, body mass index, waist circumference, and body fat percentage. It also found that it improved leptin and adiponectin, a cytokine secreted by fat tissue that protects against inflammation, enhances insulin sensitivity, and stimulates fatty acid oxidation.

Curcumin may promote cardiovascular health in a variety of ways. In the case of atherosclerosis, curcumin may attenuate inflammation by downregulating inflammatory cytokines like IL-6 and TNFα and by delaying the formation of plaque in arteries. After myocardial infarction, or heart attack, curcumin may activate NRF2, which reduces oxidative stress and prevents ischemia/reperfusion (I/R) injury. Curcumin may also help reduce scar size and prevent fibrosis after myocardial infarction by inhibiting collagens and matrix metalloproteinases (MMP), which may be harmful when excessive and play a role in plaque formation, platelet aggregation, and thrombosis. Risk factors like cigarette smoking, high homocysteine, diabetes, and high fat intake can activate MMPs.

In a 2020 randomized controlled clinical trial investigating the effects of curcumin on MMP gene expression, 70 individuals with coronary artery disease were given either 80 mg nanomicelle – which enhances solubility – curcumin per day or a placebo for 3 months. Results showed that the curcumin group showed significantly decreased expression of MMP-9 compared to placebo. Gene expression of MMP-2 was also decreased in the curcumin group, though it was not statistically significant. MMPs are implicated in other conditions such as endometriosis, psoriasis, cancer, and Alzheimer’s disease.

Finally, a 2021 meta-analysis also found that nano-curcumin supplementation may decrease fasting blood glucose, insulin, and HOMA-IR, which can increase risk for cardiovascular disease.

Cognitive and Mental Health. Curcumin may benefit Alzheimer’s disease by inhibiting amyloid-beta and hyperphosphorylated tau protein aggregation, as well as preventing oxidative stress, which can damage neurons and may be an important factor in Alzheimer’s disease development. Aging, diabetes, stroke, traumatic brain injury, and drug use are other pathways involved in increasing tau phosphorylation. Though curcumin has low ability to cross the blood-brain barrier, a 2023 Alzheimer’s disease animal model showed that brain and plasma levels of curcumin were significantly higher when combined with Gingko biloba, which is shown to increase permeability of the blood-brain barrier.

Curcumin may activate Nrf2 signaling after traumatic brain injury, which can protect the brain from inflammation that contributes to secondary brain damage and progressive damage. In an animal model of traumatic brain injury, rats were given curcumin or a control for 28 days after injury. Results showed that in addition to improving neuroinflammation, curcumin improved hippocampal neurogenesis and spatial memory.

The anti-inflammatory properties of curcumin may benefit depression. One study found that 1000 mg curcumin for 6 weeks – taken in addition to existing antidepressant medications – reduced depression rating scores, decreased inflammatory cytokines, increased BDNF, and decreased cortisol compared to placebo in male adults. Additionally, animal studies imply that curcumin may inhibit the overexpression of indoleamine 2,3-dioxygenase (IDO-1), an enzyme that is activated by pro-inflammatory cytokines, depletes tryptophan, and ultimately inhibits serotonin synthesis.

Reproductive Health. Polycystic ovarian syndrome (PCOS) is an endocrine disorder characterized by two or more of the following criteria: androgen excess, anovulation, and polycystic ovarian morphology. PCOS is multifactorial and may have a genetic component, and many of those with PCOS also experience insulin resistance and hyperinsulinemia. One study showed that, in 67 individuals with PCOS, 1500 mg curcumin for 12 weeks improved hyperglycemia and hyperandrogenemia, demonstrated by significantly decreased levels of fasting blood glucose and dehydroepiandrosterone (DHEA) compared to placebo.

Endometriosis is an estrogen-dependent inflammatory process that causes chronic pelvic pain and infertility in females of reproductive age. In endometriosis, shed endometrial tissue travels into the lower abdominal cavity. Curcumin may alleviate symptoms related to endometriosis through its anti-inflammatory, anti-angiogenic, and pro-apoptotic effects. Curcumin is also shown to have anti-proliferative effects by reducing estradiol. In the case of inflammation, curcumin may inhibit activity of the NF-κB pathway, which is implicated in inflammation as well as cell survival and growth in endometriosis. Endometriosis may have increased activity of MMPs that influence progression of endometriosis. For example, angiogenesis is initiated by MMPs and contributes to the detachment and migration of endothelial cells to new sites. Curcumin is shown to decrease  MMP-9 and MMP-2 activity.

Turmeric may be useful in reducing pain associated with menstruation. A 2023 randomized, double-blinded, placebo-controlled trial found that – compared to placebo – a single dose of a formulation containing turmeric, boswellia, and sesame provided menstrual pain relief in women with primary dysmenorrhea, or painful menstruation.

Though curcumin benefits the reproductive system, high doses may act as a contraceptive in both men and women by immobilizing sperm, reducing folliculogenesis, promoting apoptosis of oocytes and blastocysts, and decreasing embryo implantation.

Other Notable Health Benefits of Curcumin:

• Antimicrobial: Curcumin is effective against bacteria, such as aureus, E. coli, H. pylori, and M. tuberculosis. Additionally, infections caused by Candida have been treated with curcumin. Curcumin and quercetin have synergistic antimicrobial effects against S. aureus and P. aeruginosa when combined, possibly due to different modes of action.
• Bone Health: Curcumin may help maintain bone health by inhibiting osteoclast formation, promoting osteoblast proliferation, upregulating the expression of genes involved in bone formation, and reducing oxidative stress, which can reduce osteoblasts.
• Delayed Onset Muscle Soreness (DOMS): Curcumin may improve muscle damage, soreness, and strength; joint flexibility; and inflammation resulting from DOMS following exercise.
• Gastrointestinal Health: Curcumin may aid gastrointestinal health by promoting the growth of beneficial bacteria strains and improving the intestinal barrier. Additionally, a systemic review found that curcumin may help manage conditions such as IBS, ulcerative colitis, pylori infection, peptic ulcer disease, and Crohn’s disease.

How to Use Turmeric

Turmeric can be bought in whole rhizome form or as a powdered spice. It has a distinct, earthy flavor that can be used in both sweet and savory dishes as well as beverages. The downside of turmeric is that curcumin has low bioavailability and is quickly eliminated from the body. However, turmeric pairs well with black pepper, as the piperine in black pepper impairs biotransformation and enhances curcumin bioavailability by as much as 2000%.

Here are some ways to incorporate turmeric into the daily diet:

• Steep fresh grated turmeric to make tea
• Make golden milk by simmering ground turmeric and black pepper kernels in milk of choice
• Use curry powder, which contains turmeric, to make curry and other recipes
• Use ground turmeric on vegetables and in marinades
• Add peeled, fresh turmeric to smoothies
• Make a salad dressing with ground turmeric and other nutritious ingredients like pepper, ginger, lemon, and garlic
• Add ground or fresh grated turmeric to baked goods like carrot muffins
• Juice fresh turmeric with fruits and vegetables like oranges and carrots

Though curcuminoids degrade when heated, the degradation products possess similar properties, and cooked turmeric still has antioxidant activity. Curcuminoids degrade when exposed to sunlight, which may explain why turmeric stains. Purchasing turmeric in brown containers and storing it in a dark place are best practices to limit light exposure. Preferably, choose glass jars rather than plastic as these are a non-toxic alternative and more airtight compared to plastic.

To maintain the highest quality ground turmeric, it may be best to use it within 6 months. If ground turmeric becomes clumped or caked, it should be replaced as moisture has likely been introduced to the product and can contribute to harmful mycotoxins. To minimize exposure to moisture, always portion ground turmeric to a separate container before using it with steaming dishes. Fresh turmeric contains more phytochemicals and higher antioxidant activity compared to dried turmeric. It should be firm and can be stored in the refrigerator for several weeks in an airtight container.

Safety Concerns

Oxalates. Turmeric contains high levels of soluble oxalates, which can increase urinary oxalate excretion and the risk of kidney stones in susceptible individuals.

Lead Contamination. After turmeric roots are harvested, they are processed by boiling or steaming to improve odor and color. Unfortunately, lead chromate has also been used to enhance color at polishing mills, and turmeric recalls due to lead were not uncommon in the past. Due to the use of lead chromate in polishing, it may be best to use whole, unpeeled turmeric root to minimize exposure to lead. Notably, an intervention in Bangladesh in 2019 successfully reduced detectable lead in turmeric from 47% to none in 18 months, suggesting improvements are on the horizon.

Digestive Upset. High doses of turmeric in supplemental form may cause nausea and diarrhea. A personalized approach is recommended based on individual circumstances.

Contraindications. Turmeric may increase the risk of bleeding in those using warfarin and antiplatelet drugs. Though turmeric is considered a galactagogue in India, a 2021 in vitro study suggests curcumin may downregulate milk production. Due to the potential contraceptive effects of curcumin, men and women may want to avoid high doses of curcumin when trying to conceive.

If you have questions about which herbs, spices, or foods can best support your health, talk to your doctor, nutritionist, dietician, or another healthcare team member for personal options based on your circumstances. Note that spices can affect the metabolism of medications, so consult your pharmacist if taking any prescription drugs.