The nutritional analysis showed that 100 g of turmeric contains 390 kcal, 10 g total fat, 3 g saturated fat, 0 mg cholesterol, 0.2 g calcium, 0.26 g phosphorous, 10 mg sodium, 2500 mg potassium, 47.5 mg iron, 0.9 mg thiamine, 0.19 mg riboflavin, 4.8 mg niacin, 50 mg ascorbic acid, 69.9 g total carbohydrates, 21 g dietary fiber, 3 g sugars, and 8 g protein (Balakrishnan 2007). The quantity of curcumin, which is one of the key bioactive compounds in turmeric is averaging between 5-6.6%.
Curcumin is poorly absorbed by the body. This makes the bioavailability of curcumin in the form of natural turmeric still lower. When mixed with pepper bioavailability of curcumin is noted to improve.
Jagetia and Aggarwal at the Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, Houston, US, writes, “Interestingly, curcumin at low doses can also enhance antibody responses. This suggests that curcumin’s reported beneficial effects in arthritis, allergy, asthma, atherosclerosis, heart disease, Alzheimer’s disease, diabetes, and cancer might be due in part to its ability to modulate the immune system.”
As is true for any scientific analysis, there are multiple truths and there are diverging opinions. Curcumin is now available both from natural turmeric as well as synthetic sources. I have not come across any scientific evidence that will conclusively state that curcumin in natural or synthetic format is more effective. The advantage with natural turmeric is that it you benefit from its multiple components and not just curcumin.
To know more about turmeric and other herbs, you can take a look at the selection here.