Turmeric (tur mer' ik) is a widely used herbal product derived from the roots of Curcuma longa, a perennial plant belonging to the ginger family (Zingiberaceae) that is native to India but grown throughout Southern Asia and in central America. Extracts of the rhizomes of turmeric contain volatile oils and curcuminoids (such as curcumin, demethoxycurcumin and others) which are believed to be the active antiinflammatory components of the herb and are often collectively referred to as curcumin. The antiinflammatory effects of turmeric and curcumin are thought to be mediated by inhibition of leukotriene synthesis. Curcumin has also been reported to have antineoplastic effects, mediated perhaps by inhibition of intracellular kinases.

Turmeric has been used in traditional Indian (Ayurvedic) medicine to treat many conditions including indigestion, upper respiratory infections and liver diseases. Turmeric and curcumin are under active evaluation as antiinflammatory and antineoplastic agents, for treatment of diabetes and hyperlipidemia and as therapy of liver diseases including nonalcoholic steatohepatitis (NASH). The scientific bases for the purported effects of turmeric are not well established and rigorous proof of its efficacy in any medical condition is lacking. Commercial preparations of turmeric and curcumin vary widely in curcuminoid content. The recommended daily dose varies widely (100 to >1,000 mg daily), depending on the preparation used (curcuminoids vs turmeric extract), formulation (tablets, liquid, root extract, tea) and indications. Side effects are uncommon and mild but may include dermatitis and gastrointestinal upset.

Common Names: turmeric, turmeric root, Indian saffron

Latin Names: Curcuma longa, synonym Curcuma domestica; Curcuma aromatica

Background

• Turmeric, a plant in the ginger family, is native to Southeast Asia and is grown commercially in that region, primarily in India. Its rhizome (underground stem) is used as a culinary spice and traditional medicine.
• Historically, turmeric was used in Ayurveda and other traditional Indian medical systems, as well as Eastern Asian medical systems such as traditional Chinese medicine. In India, it was traditionally used for disorders of the skin, upper respiratory tract, joints, and digestive system.
• Today, turmeric is promoted as a dietary supplement for a variety of conditions, including arthritis, digestive disorders, respiratory infections, allergies, liver disease, depression, and many others.
• Turmeric is a common spice and a major ingredient in curry powder. Curcumin is a major component of turmeric, and the activities of turmeric are commonly attributed to curcuminoids (curcumin and closely related substances). Curcumin gives turmeric its yellow color.
• Turmeric dietary supplements are made from the dried rhizome and typically contain a mixture of curcuminoids. Turmeric is also made into a paste for skin conditions.

How Much Do We Know?

• Much research has been done on substances from turmeric, but their health effects remain uncertain.

What Have We Learned?

• Turmeric and curcumin have a variety of interesting biological activities, but they’re challenging to study because curcumin is unstable (it easily changes into other substances) and has low bioavailability (not much of it reaches the bloodstream) when it’s taken orally. In addition, curcumin products may differ in composition or contain more substances than expected, which makes the results of research on these products difficult to understand and compare. Because the actions of turmeric and its components in people are complex and not well understood, no clear conclusions have been reached about whether these substances have benefits for health conditions.
• NCCIH is funding research to determine whether and how curcuminoids may be converted in bone tissue into substances that may have effects on bone diseases.

What Do We Know About Safety?

• Turmeric and conventionally formulated curcumin products are probably safe when taken orally or applied to the skin in the recommended amounts.
• Efforts have been made to develop curcumin products with increased bioavailability, and many modified products are already on the market. Improving bioavailability might lead to increases in harmful effects as well as desirable ones.
• Turmeric may be unsafe for use during pregnancy in amounts greater than those commonly found in food. Little is known about whether it’s safe to use turmeric in amounts greater than those commonly found in food while breastfeeding.

Keep in Mind

• Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

Turmeric has a long history of use in Ayurvedic medicine for the treatment of inflammatory disorders. Curcumin, a chemical extracted from turmeric, is often used as a remedy for the treatment and prevention of inflammatory diseases. Preliminary findings from laboratory research suggest that curcumin, a chemical found in turmeric, may have anti-inflammatory properties, but in spite of its long history of use for inflammatory disorders, there is insufficient evidence to support the use of turmeric supplementation for these disorders.

What Does the Research Show?

• A 2021 systematic review of 10 studies involving a total of 1,287 participants found that compared with placebo, turmeric may have a beneficial effect, similar to that of nonsteroidal anti-inflammatory drugs, on knee osteoarthritis pain and function. However, the reviewers noted that variables such as optimal dosing, frequency, and formulation remain unclear at this time.
• A 2021 review found several studies highlighting the beneficial effects of turmeric and curcumin in different patent formulations for treating and preventing inflammatory and painful disorders including inflammatory bowel diseases, osteoarthritis, skin, and oral inflammation, as well as neuropathic pain. However, the reviewers noted that because of inadequate clinical trials, further high-quality studies are needed to firmly establish the clinical efficacy of this plant.
• A 2019 review evaluated current research on dietary ingredients for chronic musculoskeletal pain to inform decisions for practice and self-care, specifically for Special Operations Forces personnel in the U.S. military. Nineteen eligible dietary ingredients were assessed for quality, efficacy, and safety. Conditional evidence-based recommendations were made for the use of turmeric, as well as several other dietary supplements. In these cases, desirable effects outweighed undesirable effects, but there was uncertainty about the trade-offs, either because the evidence was low quality or because benefits and downsides were closely balanced.
• A 2020 systematic review of 11 studies found that the use of curcumin reduces the subjective perception of the intensity of muscle pain; reduces exercise-induced muscle damage through the decrease of creatine kinase; increases muscle performance; has an anti-inflammatory effect by modulating the pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-8; and may have a slight antioxidant effect.

Safety

• Turmeric is considered safe for most adults, but high doses or long-term use may cause indigestion, nausea, or diarrhea.

Preclinical studies have shown that curcumin targets inflammatory and antioxidant pathways as well as (directly) amyloid aggregation. However, the few clinical trials that have examined the effects of curcumin on Alzheimer’s disease are limited and inconsistent, making it difficult to draw conclusions about potential benefits.

What Does the Research Show?

A few preliminary clinical studies exploring the effects of curcumin on Alzheimer’s disease have been conducted.

• A 2019 systematic review found that preclinical studies have demonstrated beneficial effects of curcumin on cognition in Alzheimer’s disease. However, results of clinical trials are less consistent. Preliminary evidence from clinical studies suggests that curcumin may prevent cognitive decline in healthy populations, but the reviewers stated that more research to improve curcumin’s bioavailability is crucial and more human trials examining curcumin’s cognitive-enhancing effect are necessary.
• A 2016 randomized, placebo-controlled trial involving 96 community-dwelling, cognitively healthy, older adults found that curcumin had limited influence on cognitive function, mood, or general quality of life over 12 months. The researchers concluded that additional longitudinal studies are warranted to determine whether curcumin can slow neurodegeneration leading to cognitive decline and Alzheimer’s disease.

Safety

• Curcumin is considered safe for most adults, but high doses or long-term use may cause indigestion, nausea, or diarrhea.
• In animals, very high doses of curcumin have caused liver problems. No cases of liver problems have been reported in people.

• Curcumin comes from the underground stem of Curcuma longa, an East Indian plant. It is also called turmeric (see Question 1).
• The turmeric plant has been used for many years in traditional Asian medicine to treat many conditions (see Question 1).
• Curcumin can be found in curry powder, taken as a dried extract in pill form, or made into a paste (see Question 2).
• Few side effects have been reported from the use of curcumin products (see Question 5).
• The U.S. Food and Drug Administration (FDA) has not approved curcumin as a treatment for cancer or any other medical condition (see Question 6).

Questions and Answers About Curcumin

1. What is curcumin?

   Curcumin comes from the underground stem of Curcuma longa, an East Indian plant. It is also called turmeric. The turmeric plant has been used for many years in traditional Asian medicine to treat many conditions.

   Curcumin comes in different forms. The amount of curcumin in each product labeled as curcumin can vary, making it hard to know how much to use to treat medical conditions.

2. How is curcumin taken or given?

   Curcumin is taken by mouth as a dietary supplement. It is also found in curry powder, as a major part of turmeric. Curcumin can also be made into a paste to treat skin conditions.

3. Have any laboratory or animal studies been done using curcumin?

   In laboratory studies, tumor cells are used to test a substance to find out if it is likely to have any anticancer effects. In animal studies, tests are done to see if a drug, procedure, or treatment is safe and effective in animals. Laboratory and animal studies are done before a substance is tested in people.

   Laboratory and animal studies have tested the effects of curcumin. For information on laboratory and animal studies done using curcumin, see Laboratory/Preclinical Studies in the health professional version of this summary.

4. Have any studies of curcumin been done in people?

   Early phase trials have been done with small numbers of people to see if curcumin products are safe and work in the following ways:

   • To prevent cancer.
   • To treat cancer.
   • To improve quality of life.
   • To manage cancer treatment-related side effects.

   Researchers have looked at curcumin products for the prevention and treatment of a variety of cancers, including colorectal cancer, oral cancer, and liver cancer. There is not enough evidence to know if curcumin products can prevent or treat cancer.

   Cancer prevention and treatment trials

   • One study looked at the impact of oral curcumin on lesions in the lining of the colon and the rectum known as aberrant crypt foci (ACF). These lesions can be early warning signs of polyps and colorectal cancer. Although patients who received curcumin saw a decrease in ACF, the differences were not significant when compared to the group who did not receive curcumin.
   • A randomized trial looked at the use of an oral curcumin product in 223 patients with oral leukoplakia (thick white patches in the mouth). Compared to the placebo group, patients who received the curcumin product showed improved conditions that were maintained at 6 months. No further benefit was seen with treatment that lasted longer than 6 months.
   • Results from a study of 102 patients with nonalcoholic fatty liver disease (NAFLD) showed that a curcumin product was linked with reduced body mass index and waist size. Many patients who took the curcumin product showed improved liver ultrasound findings and biomarkers of liver inflammation in the blood, compared to the control group.
   • A later study that combined results from four randomized controlled trials of 228 patients with NAFLD who took curcumin products showed similar results for biomarkers of liver inflammation.
   • Results of studies that used curcumin products with traditional cancer treatments have been mixed. Studies of patients with adrenocortical cancer, breast cancer, prostate cancer, pancreatic cancer, or colorectal cancer have shown improved results when using a curcumin product as an adjuvant therapy. Other studies did not show an improvement in disease. For more information on these study results, see the Cancer Treatment section in the health professional version of this summary.

   Curcumin products have been studied in early phase trials to find out their impact on cancer treatment-related side effects and quality of life.

   Cancer treatment-related side effects trials

   • Although studies have been mixed on oral curcumin given to treat radiation-induced dermatitis, a small study reported a topical cream that contained turmeric reduced dermatitis from radiation therapy.
   • Delayed onset and severity of mucositis (often seen as sores in the mouth) has been reported in trials that used a mouthwash product or oral capsule that had curcumin in it.
5. Have any side effects or risks been reported from curcumin?

   Few side effects have been reported from the use of products with curcumin. The most common complaint is digestive problems. A small study of patients who took a curcumin product with an anticancer drug found that 1 in 3 patients stopped using the curcumin product because of constant bloating.

6. Is curcumin approved by the U.S. Food and Drug Administration (FDA) for use as a cancer treatment in the United States?

   The FDA has not approved the use of curcumin as a treatment for cancer or any other medical condition.

   Curcumin is available in the United States as a dietary supplement. The FDA does not approve dietary supplements as safe or effective. The company that makes the dietary supplements is responsible for making sure that they are safe and that the claims on the label are true and do not mislead the consumer. The way that supplements are made is not regulated by the FDA, so all batches and brands of curcumin supplements may not be the same.

Many natural products sold as dietary supplements are marketed for promoting health and well-being and preventing disease. However, there is often little to no evidence to support these claims. Here are five myths about popular natural products often used for disease prevention and wellness reasons and what the science really says about them for improving health.

Remember, take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

1. Myth: Herbs such as valerian, chamomile, and kava are effective for insomnia.
   Fact: Various herbs such as valerian, chamomile, and kava, and homeopathic medicines sometimes used as sleep aids have not been shown to be effective for insomnia, and important safety concerns have been raised about a few. For example, kava supplements have been linked to a risk of severe liver disease. However, there is evidence to suggest that using relaxation techniques, such as progressive relaxation, guided imagery, biofeedback, or deep breathing exercises, before bedtime can be helpful components of a successful strategy to improve sleep habits. Current evidence also suggests that melatonin may be useful in treating several sleep disorders, including jet lag, delayed sleep phase disorder, and sleep problems related to shift work.

2. Myth: The herb passionflower can reduce stress and improve overall health.
   Fact: There are very few studies of passionflower conducted in people and therefore insufficient evidence to determine whether passionflower is efficacious for any condition. However, there is some scientific evidence to date that suggests mindfulness meditation—a mind and body practice which cultivates abilities to maintain focused and clear attention, and develop increased awareness of the present—may help reduce symptoms of stress, including anxiety and depression. Results from a small body of research suggest that yoga may also affect stress and anxiety symptoms.

3. Myth: A daily dose of a vitamin C supplement will prevent the onset of the common cold.
   Fact: Several reviews have concluded that prophylactic vitamin C does not reduce the incidence of colds in the general population, but may be useful in reducing incidence of colds for people exposed to brief periods of severe physical exercise (e.g., marathon runners, skiers, and soldiers training in subarctic conditions). 

4. Myth: Taking garlic supplements will prevent heart disease.
   Fact: There is no evidence that garlic supplements prevent heart disease. However, evidence from small studies is mixed about whether garlic supplements reliably lower cholesterol levels or change other known risk factors for cardiovascular disease.

5. Myth:Turmeric (curcumin) and Ginkgo biloba supplements can prevent the onset of dementia and Alzheimer’s disease in people.
   Fact: Although there is some evidence in laboratory studies that curcumin may affect brain function and the development of dementia, these results have not been demonstrated in clinical trials. In several large clinical trials, Ginkgo biloba has not been shown to effective in reducing either the overall incidence rate of dementia or Alzheimer’s disease incidence.