Sunday, August 20, 2017

Than-lines: Does thanakha work as sunscreen?

This is the story of how I found myself lying shirtless on a sidewalk in Yangon’s downtown district at 2pm on a Sunday. You might have seen me. You should have seen me – a pasty white man with black tape dividing my torso into four distinct sectors, swatting flies away from my melting chest. As I was situated in front of St Mary’s Cathedral, some nervous church officials expressed concerns that my act was one of protest or condemnation; I did, after all, have a black cross taped to my body.

Intrepid Myanmar Times correspondent RJ Vogt prepares to put Myanmar's traditional sunscreen to the test. Photos: Myo Satt / The Myanmar TimesIntrepid Myanmar Times correspondent RJ Vogt prepares to put Myanmar's traditional sunscreen to the test. Photos: Myo Satt / The Myanmar Times

But it was no civil unrest. It was a science experiment, an endeavour to determine the sun-blocking potential of thanakha.

For context: I am almost preposterously white-skinned. Translucent, really – when standing in a swimming pool of clear water, my feet often blend in with the white pool bottom. In direct sunlight, I can burn in less than 20 minutes. Where others tan, I boil like a freshly caught lobster.

As a result I moved to tropical Myanmar with a stout supply of sunscreen. During my first week here I was shocked to find so many of my new neighbours wearing a sort of sunscreen of their own, the ubiquitous thanakha beauty cream that doubles as skin protectant. On my first assignment in Magwe Region, village children came running up to me to examine my fair skin; I was equally interested in the yellow thanakha cream, made from tree bark, adorning their cheeks.

The conventional explanation for the cream’s popularity is that it is equal parts cosmetic and ointment. Myanmar people have long ritually applied the cream to clear up acne, cool the skin and prevent UV damage. Even with the arrival of Western beauty products, thanakha remains the reigning cosmetic of choice among women and children (if less so for grown men, apprehensive of appearing too feminine).

It is, by most local accounts, a miracle cream, even used in organic products such as US-based Manda Organic Sun Paste and Thailand’s Organic Thanakha Soap. But would thanakha protect my body from sunburn as well as the Western sunblock I brought from home?

The experiment began. First, I split my torso into quadrants with some black electrical tape. Then, with the help of my colleague Myo Satt, I acquired a piece of the Limonia acidissima – or wood apple – tree bark that grows in central Myanmar and creates thanakha. He showed me how to make the paste, grinding the bark (K4000) into a coarse stone and mixing the remnants with water. It truly cools the skin, I discovered as I slathered it on the top right quadrant of my torso.

For the top left quadrant, I used the cheaper store-bought thanakha (K700) in order to compare authentic cream versus commercial. Sold in a small tub, this version was already pasty. I mixed it with water and applied it to my skin, coating the surface.

On the bottom right side of my stomach, I applied Coppertone SPF 30 brought from the US. Similar sunscreen in Myanmar can cost upward of K10,000, making it the most expensive option for UV protection.

As a control component, I braved a naked and unprotected bottom left side. I expected to be able to compare the three versions of sunscreen against the plain, steaming burn.

The results. Upper left quadrant: homemade thanakha. Upper right quadrant: store-bought thanakha. Bottom left quadrant: susncreen. Bottom right quadrant: bare and burnedThe results. Upper left quadrant: homemade thanakha. Upper right quadrant: store-bought thanakha. Bottom left quadrant: susncreen. Bottom right quadrant: bare and burned

The experiment went as planned, though I did not expect to generate so much curiosity. More than once, a concerned pedestrian informed me that I would get burned by the sun, laying out in the open like that. I know, I kept saying. That’s the point.

After an hour of sweating and another of hour of waiting for the burn to set, the evidence was clear – thanakha works as a sun protectant, especially if homemade. Though not as effective as SPF 30, both types of thanakha managed to keep my chest significantly less red than the unprotected region.

Part of the reasoning is physical – the paste acts as a protective layer on top of the skin, not unlike the way mud would protect against sunburn. And in a 2004 study conducted by students at Chung-Ang University in Seoul, South Korea, and published in The Journal of Plant Biology, an active compound in thanakha known as marmesin was found to absorb over half of the UV ray spectrum that reaches earth through the ozone layer. The study concluded that “marmesin could be commercially useful as a natural UV-A filtering product”.

So there may be a scientific aspect – thanakha’s active ingredient specifically helps with UVA rays, which contribute more directly to wrinkling, leathering, sagging and other light-induced effects of aging. UVB rays, which cause sunburn, are not absorbed as readily. This could be one reason why the thanakha-covered areas did see some slight reddening.

Still, Dr Christoph Gelsdorf from the SOS Clinic in Yangon pointed out that my experiment is only a case study and does not prove anything about thanakha‘s effects against skin cancer.

“You can say objectively that it caused less burn,” he said. “But the thing to remember is that with sunscreen, we’re protecting against more than sunburn – we’re protecting against skin cancer. Sunburn is just a proxy for skin cancer.”

A more extensive, randomised study conducted over large populations for extended periods of time is necessary before any kind of SPF rating could be accurately awarded to thanakha, but Dr Gelsdorf noted that this case study is a start to future research.

“I applaud what you’ve done because you’ve given literature a case study of the possible benefits of thanakha,” he said. “Though it does not prove causality, it could be a first step in additional research studies.”

Conclusion: In a pinch, use thanakha to keep your skin cool and relatively sunburn-free. But to prevent skin cancer, you’re better off using sunscreen – at least until a few more sidewalk studies are conducted.