Of course, including turmeric in your diet does not have a therapeutic effect. The therapeutic dose as I know it is 200-500mg of active curcumin, however there are other components of whole turmeric, which can also be helpful and enhance absorbability of the curcumin. I believe adding turmeric into your diet can be helpful and used to support the body, not as any sort of cure-all :)
References:
1. Sharma, R. a., Gescher, a. J. & Steward, W. P. Curcumin: The story so far. Eur. J. Cancer 41, 1955–1968 (2005).
2. Gupta, S. C., Kismali, G. & Aggarwal, B. B. Curcumin, a component of turmeric: From farm to pharmacy. BioFactors 39, 2–13 (2013).
3. Nguyen, T. A. & Friedman, A. J. Curcumin: a novel treatment for skin-related disorders. J. Drugs Dermatol. 12, 1131–7 (2013).
4. Shehzad, A., Rehman, G. & Lee, Y. S. Curcumin in inflammatory diseases. BioFactors 39, 69–77 (2013).
5. Zhou, H., Beevers, C. S. & Huang, S. The targets of curcumin. Curr. Drug Targets 12, 332–347 (2011).
6. Aggarwal, B. B. & Harikumar, K. B. Potential therapeutic effects of curcumin, the anti-inflammatory agent, against neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. Int. J. Biochem. Cell Biol. 41, 40–59 (2009).
7. Anand, P., Kunnumakkara, A. B., Newman, R. a. & Aggarwal, B. B. Bioavailability of curcumin: Problems and promises. Mol. Pharm. 4, 807–818 (2007).
8. Heng, M. C., Song, M. K., Harker, J. & Heng, M. K. Drug-induced suppression of phosphorylase kinase activity correlates with resolution of psoriasis as assessed by clinical, histological and immunohistochemical parameters. Br. J. Dermatol. 143, 937–49 (2000).
9. Sonavane, K. et al. Topical curcumin-based cream is equivalent to dietary curcumin in a skin cancer model. J. Skin Cancer 2012, 147863 (2012).
10. Gupta, S. C., Patchva, S. & Aggarwal, B. B. Therapeutic roles of curcumin: lessons learned from clinical trials. AAPS J. 15, 195–218 (2013).
11. Reddy, S. & Aggarwal, B. B. Curcumin is a non-competitive and selective inhibitor of phosphorylase kinase. FEBS Lett. 341, 19–22 (1994).
12. Gupta, S. C. et al. Downregulation of tumor necrosis factor and other proinflammatory biomarkers by polyphenols. Arch. Biochem. Biophys. 559, 91–99 (2014).
13. Aggarwal, B. B. et al. TNF blockade: an inflammatory issue. Ernst Scher. Res Found Work. 161–186 (2006).
14. Thangapazham, R. L., Sharad, S. & Maheshwari, R. K. Skin regenerative potentials of curcumin. BioFactors 39, 141–149 (2013).
15. Briganti, S. & Picardo, M. Antioxidant activity, lipid peroxidation and skin diseases. What’s new. J. Eur. Acad. Dermatol. Venereol. 17, 663–669 (2003).
16. Kurd, S. K. et al. Oral curcumin in the treatment of moderate to severe psoriasis vulgaris: A prospective clinical trial. J. Am. Acad. Dermatol. 58, 625–631 (2008).
17. Antiga, E., Bonciolini, V., Volpi, W., Bianco, E. Del & Caproni, M. Oral Curcumin ( Meriva ) Is Effective as an Adjuvant Treatment and Is Able to Reduce IL-22 Serum Levels in Patients with Psoriasis Vulgaris. Biomed Res. Int. 1–7 (2015). doi:10.1155/2015/283634
18. Cheng, A. L. et al. Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions. Anticancer Res. 21, 2895–900 (2001).
19. Shoba, G. et al. Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Med. 64, 353–356 (1998).
20. Chandran, B. & Goel, A. A randomized, pilot study to assess the efficacy and safety of curcumin in patients with active rheumatoid arthritis. Phytother. Res. 26, 1719–25 (2012).
21. Belcaro, G. et al. Efficacy and safety of Meriva®, a curcumin-phosphatidylcholine complex, during extended administration in osteoarthritis patients. Altern. Med. Rev. 15, 337–344 (2010).
22. Hutchins-Wolfbrandt, A. & Mistry, A. M. Dietary turmeric potentially reduces the risk of cancer. Asian Pacific J. Cancer Prev. 12, 3169–3173 (2011).
23. Polasa, K., Raghuram, T. C., Krishna, T. P. & Krishnaswamy, K. Effect of turmeric on urinary mutagens in smokers. Mutagenesis 7, 107–109 (1992).
24. Frenkel, M. et al. Integrating dietary supplements into cancer care. Integr. Cancer Ther. 12, 369–84 (2013).
25. Toda S, Miyase T, Arichi H, et al. Natural antioxidants. Antioxidant compounds isolated from rhizome of Curcuma longa L. Chem Pamacol Bull (Tokyo) 1985;33:1725-1728.
26. Zhao B, Li XJ, He RG, et al. Scavenging effect of extracts of green tea and natural antioxidants on active oxygen radicals. Call Biophys 1989;14:175-185.
26. Deodhar SD, Sethi R, Srimal RC. Preliminary studies on anti-rheumatic activity of curcumin (diferuloyl methane). Ind J Med Res 1980;71:632-634.
27. Satoskar RR, Shah SJ, Shenoy SG. Evaluation of anti-inflammatory property of curcumin (diferuloyl methane) in patients with postoperative inflammation. Int J Clin Pharmacol Ther Toxicol 1986;24:651-654.
28. Ammon HP, Wahl MA. Pharmacology of Curcuma longa. PLanta MEd 1991;57:1-7.
29. Kiso Y, Suzuki Y, Wantanabe N, et al. Antihepatotoxic principles of Curcuma longa rhizomes. Planta Med 1983;49:185-187.
30. Lim GP, Chu T, Yang F, et al. The curry spice curcumin reduces oxidative damage and amyloid pathology in an Alzheimer transgenic mouse. J Neurosci 2001;21:8370-8377.
31. Lutomski J, Kedzia B, Debska W. Effect of an alcohol extract and active ingredients from Curcuma longa on bacteria and fungi. Planta Med 1974;26:9-19.
https://www.ncbi.nlm.nih.gov/pubmed/28771714
https://www.ncbi.nlm.nih.gov/pubmed/28059453
https://www.ncbi.nlm.nih.gov/pubmed/27213821
http://www.whfoods.com/genpage.php?tname=nutrientprofile&dbid=8
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3882399/