Hot buns indeed! In a new experiment, 19 participants offered up their backsides in a test of cannabidiol (CBD) as a potential sun-screen agent.

CBD is an ingredient derived from the cannabis plant, gaining popularity globally as a cure-all.

Much of the evidence so far for CBD’s efficacy in treating pain, addiction or anxiety is either mixed, weak or based on animal studies.

This was a pilot clinical trial – from George Washington University School of Medicine and Health Science – that featured human participants.

It didn’t rely on questionnaires or participant feedback. The findings were based on objective evidence.

That is, the extent to which participants were damaged or not by (artificial) sunburn redness at the end of the ordeal. And the extent of damage to skin cells and DNA.

The sizzling study

The participants all had what’s known as Fitzpatrick skin types I-III. These are the three palest skin types.

These ranged from pure white skin that always burns and never tans … to skin that moderately burns and may tan gradually to a light brown.

The creams (experimental and control) were applied twice daily, for 14 days.

The idea was to prepare the skin with the cream during this time, in effect as a potential vaccination against ultraviolet radiation.

The treated buttocks were then exposed to up to three times the amount of ultraviolet-A radiation needed to burn or injure the skin.

After 24 hours, skin biopsies were taken for analysis to assess for cellular and DNA damage well known to be associated with UVA exposure.

Over-exposure to UVA can prematurely age the skin and potentially leads to skin cancers.

The results

According to a statement from George Washington, 21 per cent of participants showed less redness on CBD-treated skin. This is compared to control-treated skin at 24 hours post-exposure.

Skin thickening on biopsies, of the sort caused by sun exposure, was significantly reduced in the CBD-treated skin. Again, this was when  compared to controls.

This suggests that CBD prevented the expected UVA skin cell injury.

Most importantly, from the researchers’ perspective, application of CBD cream effectively reduced DNA damage and DNA mutations associated with UVA-induced skin ageing/damage and ultimately skin cancer.

What the researcher says

Adam Friedman is professor and chair of dermatology at the GW School of Medicine and Health Sciences. He is a corresponding author of the new paper.

He told Medical New Today: “We know that we need to throw everything we have at protecting our skin from the harmful effects of UV radiation.”

He said there were “even more limited options against UVA which penetrates deeper into the skin”.

No one approach “is perfect and foolproof”.

The study didn’t serve as an argument for a nano-CBD formulation to replace standard sunscreen.

However, he said that a CBD formulation could be an additional weapon against UVA’s harmful effects. This would be in combination “with our current modalities”.

CBD is derived from the same cannabis plant that also contains THC (tetrahydrocannabinol), the psychoactive compound that gets people high.

CBD has no psychoactive effects, and is widely considered to be safe.

It will be years before its effectiveness in treating a range of conditions is established or debunked. For the moment, marketing is way ahead of the science.

Expert reaction

Sherry Yafai, a Californian medicine physician and a cannabis researcher, not involved in the study, told Medical News Today: “It’s impressive, but I think there’s still a lot more that can be done.”

She said the 21 per cent effectiveness needed to be improved upon.

In terms of medicine, “we hope that things have at least 40 or 50 per cent effectiveness”.

If CBD was made more effective, she said, the number of people treated for damaged skin would go down.

“The next question becomes is it the amount of CBD that was being utilised?”

Yafai suggested the answer might be increasing the dosage.