From page 28 of the July-August 2010 issue of Women's Health:
As one of the more "aged" members of this collective, I felt compelled to address the benefits of turmeric, also known as Indian saffron because of its deep golden color. According to The World's Healthiest Foods:
Turmeric has a peppery, warm and bitter flavor and a mild fragrance slightly reminiscent of orange and ginger, and while it is best known as one of the ingredients used to make curry, it also gives ballpark mustard its bright yellow color.
Turmeric comes from the root of the Curcuma longa plant and has a tough brown skin and a deep orange flesh. Turmeric has long been used as a powerful anti-inflammatory in both the Chinese and Indian systems of medicine. Turmeric was traditionally called "Indian saffron" because of its deep yellow-orange color and has been used throughout history as a condiment, healing remedy and textile dye.
Fellow Scientopian Krystal D'Costa of Anthropology in Practice has blogged about the use of turmeric in Gaye Holud, a Bengali wedding ritual, where its yellow color sanctifies the couple the evening before their vows. The post confirms what I remember most from dropping curry in my lap: it stains!
To further demonstrate this property of the spice, I performed an experiment (once a scientist, always a scientist). First I put 1/4 teaspoon of lotion (my vehicle) in each of two stainless steel containers. I then mixed 1/8 teaspoon of turmeric into one of the containers.
I applied roughly equal amounts of each onto the back of my left hand. Even after rubbing both in, a yellow cast can be seen on the turmeric side, even on my olive skin. My fair-skinned daughter would look positively jaundiced!
When googling turmeric and skin care, one site provided a realistic, sober assessment of the spice's active ingredient, curcumin:
If you asked a dermatologist or skin care scientist what features they would want in a beneficial skin care ingredient, the answer may include the ability to neutralize free radicals, reduce inflammation, modulate abnormal cell growth, reduce UV damage, and inhibit accumulation of age-related pigments. Interestingly enough, curcumin's resume matches all of the above quite well. Also, considering that skin is a lipid rich tissue (just as the brain is), curcumin may turn out to be not just neuroprotector but skin protector as well.
That said, the research into the effects of curcumin on skin aging is scant or absent (depending on where you draw the quality line). There is some evidence that topical curcuminoids reduce the incidence of skin tumors in mice as well as partly prevent UV damage. However, realistic human clinical studies are required to assess practical skin benefits of curcumin, if any.
Being a sciencey-type person, I then went to the primary literature via PubMed. My search used the terms "topical" and "curcumin" and located 58 citations, including 10 review articles. One that caught my attention studied its use in photoaging in mice; a portion of the abstract includes the following:
Curcumin (diferuloylmethane) is a phytochemical with diverse antioxidant and antiinflammatory properties. However, it shows a poor topical bioavailability.
The authors went on to test the effects of encapsulated vesicles of curcumin and demonstrated that it restored redox balance to damaged skin. Free curcumin in lotion did nothing, presumably because it cannot penetrate skin!
So leave your turmeric in the kitchen (unless you're Bengali or otherwise engaged in a paint-the-body-yellow ritual of some sort); it is not going to stop wrinkles mixed in your moisturizer! Studies are underway using non-pigmented metabolites and effective delivery vehicles, so someday curcumin may be in our make-up case and sunblock. In the meantime, eating curry and yellow mustard may provide some anti-aging benefits, as well as delicious foods!