Curcumin may prove useful for depression, but more research is needed.
Curcumin's therapeutic potential in the treatment of depression stems from its neuroprotective effects. Think of depression as a kind of stress-related injury to the brain. Curcumin bolsters antioxidant defense and reverses some of the negative changes incurred by depression.
You can start your research with these resources:
The study concluded: "This study provides first clinical evidence that curcumin may be used as an effective and safe modality for treatment in patients with MDD without concurrent suicidal ideation or other psychotic disorders."
- Curcumin and major depression: a randomised, double-blind, placebo-controlled trial investigating the potential of peripheral biomarkers to predict treatment response and antidepressant mechanisms of change
Conclusion: "Our findings demonstrate that curcumin supplementation influences several biomarkers that may be associated with its antidepressant mechanisms of action."
- Curcumin for the treatment of major depression: a randomised, double-blind, placebo controlled study
Conclusion: "Partial support is provided for the antidepressant effects of curcumin in people with major depressive disorder, evidenced by benefits occurring 4 to 8 weeks after treatment."
Curcumin has many properties that promote health and wellbeing.1 Curcumin has been noted to have these effects:
These properties enable curcumin to protect your body against several diseases and conditions including:2
- Alzheimer’s disease
Why You Should Consider Supplementing Curcumin
Curcumin drew my attention because it's naturally present in food like Indian curries. Though the health benefits of taking curcumin aren't fully fleshed out, it's unlikely to have serious negative health consequences.
Curcumin also piqued my interest because it:
- Increases BDNF (bran-derived neurotrophic factor), which keeps the brain resilient and plastic.20
- Dissolves beta amyloid plaques, which are the hallmark of Alzheimer's disease.21
- Enhances neurogenesis or protects against decrements in neurogenesis due to depression, genetics, stress, etc.22,23
Why You Should Remain Skeptical
As always, any supplement should be taken with water and a healthy dose of skepticism. Publication bias, financial incentives and other clandestine motives bias the results of scientific studies. For example many of the bioavailabity and absorption studies on curcumin are funded by particular brands of curcumin supplements. See this post for a discussion about the best curcumin supplements.
The Pollution of the Chemical Literature
A paper entitled Chemistry: Chemical con artists foil drug discovery named curcumin as a compound that can generate false-positives in drug screens. In other words, when biologists are looking for drug leads they screen compounds against proteins to see how they affect their activity. But curcumin is one of half a dozen compounds that show activity against 1/3 of all proteins it was screened against, dubbed a pan-assay interference compound (PAINS).
From the paper:
A typical assay screens many thousands of chemicals. ‘Hits’ become tools for studying the disease, as well as starting points in the hunt for treatments. But many hits are artefacts — their activity does not depend on a specific, drug-like interaction between molecule and protein. A true drug inhibits or activates a protein by fitting into a binding site on the protein. Artefacts have subversive reactivity that masquerades as drug-like binding and yields false signals across a variety of assays.
Origin and History
Curcumin is derived from the Tumeric, a relative of the ginger family. It was originally used in Asian countries as a medical herb to cure a wide variety of diseases.3
Curcumin is part of a group called curcuminoids that make up a large portion of the turmeric plant. In addition to its own health benefits, curcumin has synergistic effects with other curcuminoids to treat parasitic diseases.4
Bioavailability and Metabolism
Unfortunately, curcumin has a relatively low oral bioavailability. This means that large doses (3,600 to 12,000mg) are needed in order to realize its health benefits. However, since curcumin taken orally at high doses has no toxic effects, its low bioavailability is not a huge concern.5
Curcumin can also be taken with substances that improve its bioavailability. For example, curcumin plus L-piperonylpiperazine (the substance that gives black pepper that extra spice) increases curcumin's bioavailability up to 154%!
Antioxidant Properties of Curcumin
Curcumin is a powerful antioxidant that blocks the activity of harmful free radicals in multiple ways. Curcumin itself can directly inhibit free radicals through its unique structure.
It can also enhance the activity of antioxidant enzymes (such as catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx) and heme oxygenase-1 (OH-1) in the body to reduce free radical activity and inhibit processes that produce more radicals such as lipid peroxidation.6 Lastly, curcumin increases the activity of detoxifying enzymes in the liver and kidney to protect against cancer-promoting processes. Curcumin also protects the brain from oxidative stress by activating Akt/Nr2—a signaling pathway. This pathway protects nerve cells by suppressing ROS aka reactive oxygen species.7
Like with oxidative stress, curcumin decreases inflammation in a number of ways. Since oxidative stress can lead to inflammation, curcumin reduces inflammation by suppressing oxidative stress through activation of the Akt/Nr2 pathway.8 The supplement also inhibits pro-inflammatory proteins, such as cytokines, interleukins, chemokines and inflammatory enzymes (cycloxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS)). Through these behaviors, curcumin treats several inflammatory diseases such as9
- Rheumatoid Arthritis
- Inflammatory Bowel Disease
- Chronic Pancreatitis
- Chronic Gastritis
Curcumin prevents inflammation in respiratory diseases like allergies and asthma by downregulating levels of receptors that transmit inflammatory signals. Curcumin also binds to reactive oxygen species to prevent them from causing further oxidative stress. To treat joint pain in rheumatoid arthritis, Curcumin promotes cell death programs in synovial fibroblasts, which perpetuate the disease and inflammation.10
The benefits of Curcumin on Neurological Diseases
Curcumin has been shown to be effective in protecting nerve cells in several neurological diseases,11 such as:
- Alzheimer’s Disease - Parkinson’s Disease - Huntington’s disease
Curcumin protects these cells by applying a combination of its antioxidant, anti-inflammatory and anti-protein aggregation characteristics in vital regions of the central nervous system. Its inhibition of neuroinflammation is especially important in preventing the progression of neurodegenerative diseases. Take Alzheimer’s disease (AD) for example. People with AD form protein aggregates called Aβ plaques. The plaques cause a great deal of damage including inflammation. Dysfunction of the clearing mechanism in the AD patient brains prevents these plaques from being removed. However, curcumin can activate immune cells in the nervous system called microglia to remove these plaques. Curcumin can also inhibit the further formation of these plaques.12
In the case of Parkinson’s disease (PD), curcumin treatment was found to reduce nerve cell damage, prevent cell death, activate microglia and improve walking in animal models. Curcumin also improved movement and memory deficits in the mouse models of Huntington’s disease.
The benefits of Curcumin on Lung Injury
Curcumin has also shown to be effective in improving respiratory disease symptoms: The most notable diseases being:13
- Pulmonary Fibrosis - Allergies - Asthma
Curcumin improves the complications resulting from these diseases by suppressing inflammatory cell accumulation, inhibiting over-production of pro-inflammatory proteins and increasing reactive oxygen species scavengers (substances that bind to free radicals to prevent them from causing damage to the body). Curcumin suppresses inflammatory cell accumulation in pulmonary fibrosis primarily by decreasing mediators of the inflammatory response. The supplement behaves similarly to reduce inflammatory responses associated with asthma.
The benefits of Curcumin on Metabolic Syndrome
Not surprisingly, curcumin is also effective at reducing risk factors for metabolic syndrome. A metabolic syndrome is a group of risk factors that increase your chances of developing heart disease. These risk factors are associated with obesity, insulin resistance, and diet and can lead to the development of high blood pressure, high blood sugar, and obesity. Treatment with curcumin has been shown to regulate obesity and insulin resistance by decreasing pro-inflammatory proteins in diabetic animals.14 Other beneficial effects include:
- Reduction of blood sugar levels
- Reduction of fat in blood plasma
- Reduction of cholesterol and triglyceride
- Reduction in low-density lipoprotein (LDL; the bad cholesterol)
- Increase in high-density lipoprotein (HDL; the good cholesterol)
Anti-cancer Properties of Curcumin
Studies have investigated the anti-cancer potential of curcumin. Yet only a handful of reports has found treatment with the supplement to be therapeutically beneficial on its own.
So now researchers are investigating its use as an adjuvant anti-tumor therapy. Many promising results have emerged.
Curcumin treatment improved the outcome of mice with colon cancer by inhibiting processes that generate reactive oxygen species and activating those that reduce free radical activity.
Through regulation of several cancer-related genes, curcumin is also capable of inhibiting cancer progression and development. Curcumin also regulates pathways involved in cancer progression. Because inflammation is carcinogenic, curcumin is most effective through activation of pathways that modulate inflammation.15
Curcumin has a plethora of health benefits.
Leveraging its anti-inflammatory and anti-oxidant abilities, the plant derivative provides reduces the risk for diseases including neurological, cardiovascular, and lung diseases. With all these benefits, curcumin could potentially be used to develop future therapeutics.
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Zhang DW, Fu M, Gao SH, Liu JL. Curcumin and diabetes: a systematic review. Evid Based Complement Alternat Med. 2013;2013:636053. ↩
Hatcher H, Planalp R, Cho J, Torti FM, Torti SV. Curcumin: from ancient medicine to current clinical trials. Cell Mol Life Sci. 2008;65(11):1631-52. ↩
Funk JL, Oyarzo JN, Frye JB, et al. Turmeric extracts containing curcuminoids prevent experimental rheumatoid arthritis. J Nat Prod. 2006;69(3):351-5. ↩
Prasad S, Tyagi AK, Aggarwal BB. Recent developments in delivery, bioavailability, absorption and metabolism of curcumin: the golden pigment from golden spice. Cancer Res Treat. 2014;46(1):2-18. ↩
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Rajeswari A. Curcumin protects mouse brain from oxidative stress caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Eur Rev Med Pharmacol Sci. 2006;10(4):157-61. ↩
Aggarwal BB, Harikumar KB. Potential therapeutic effects of curcumin, the anti-inflammatory agent, against neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. Int J Biochem Cell Biol. 2009;41(1):40-59. ↩
Jacob A, Wu R, Zhou M, Wang P. Mechanism of the Anti-inflammatory Effect of Curcumin: PPAR-gamma Activation. PPAR Res. 2007;2007:89369. ↩
Abidi A, Gupta S, Agarwal M, Bhalla HL, Saluja M. Evaluation of Efficacy of Curcumin as an Add-on therapy in Patients of Bronchial Asthma. J Clin Diagn Res. 2014;8(8):HC19-24. ↩
Kulkarni SK, Dhir A. An overview of curcumin in neurological disorders. Indian J Pharm Sci. 2010;72(2):149-54. ↩
Cole GM, Teter B, Frautschy SA. Neuroprotective effects of curcumin. Adv Exp Med Biol. 2007;595:197-212. ↩
Venkatesan N, Punithavathi D, Babu M. Protection from acute and chronic lung diseases by curcumin. Adv Exp Med Biol. 2007;595:379-405. ↩
Yang YS, Su YF, Yang HW, Lee YH, Chou JI, Ueng KC. Lipid-lowering effects of curcumin in patients with metabolic syndrome: a randomized, double-blind, placebo-controlled trial. Phytother Res. 2014;28(12):1770-7. ↩
Wilken R, Veena MS, Wang MB, Srivatsan ES. Curcumin: A review of anti-cancer properties and therapeutic activity in head and neck squamous cell carcinoma. Mol Cancer. 2011;10:12. ↩
Franco-robles E, Campos-cervantes A, Murillo-ortiz BO, et al. Effects of curcumin on brain-derived neurotrophic factor levels and oxidative damage in obesity and diabetes. Appl Physiol Nutr Metab. 2014;39(2):211-8. ↩