FILE - In this April 2, 2014 file photo, Teresa Lynch, owner of Dynamic Tanning in DeKalb, Ill., wipes down a tanning bed. Tanning beds and sun lamps will carry new warnings that they should not be used by anyone under age 18, under a government action Thursday, May 29, 2014, aimed at reducing rising rates of skin cancer linked to the radiation-emitting devices. (AP Photo/Daily Chronicle, Monica Maschak, File) MANDATORY CREDIT Teresa Lynch, owner of Dynamic Tanning in DeKalb, Ill., wipes down a tanning bed.  (AP Photo/Daily Chronicle, Monica Maschak)

One recreational activity demands a beach towel and a pair of sunglasses.

The other requires a dealer and a safe place to cook up and tie off.

Catching some rays seems much more wholesome than injecting heroin.

However, a recent study found commonalities between lying on a beach and the deadly drug that played a role in the deaths of Philip Seymour Hoffman, Sid Vicious and Samuel Taylor Coleridge.

“It may be necessary … to more proactively protect individuals, including teens, from the risks of an avoidable, potentially life-threatening exposure and to view recreational tanning and opioid drug abuse as engaging in the same biological pathway,” researchers led by Gillian L. Fell and Kathleen C. Robinson of Harvard Medical School concluded in a study published in the journal Cell.

The link between tanning and Mr. Brownstone: endorphins.

The BBC’s worthy summary of the study’s methodology:

Mice with a shaved back were exposed to the equivalent of half an hour of midday Florida sun every day for six weeks.

They showed UV radiation led to the production of a protein in the skin called proopiomelanocortin. This is broken down into the pigment melanin, which gives you a tan, but the team showed pleasure chemicals, or endorphins, were also produced.

The chemicals act on the same systems in the body as other opioids such as heroin and morphine.

Giving the mice drugs to block opioids, which are used in rehab clinics, led to withdrawal symptoms including shaking and tremors.

The mice then started to avoid the place where the drugs were being administered, which the researchers said was a hallmark of addictive behaviour.

Another doctor thought the study worthwhile, but thought comparing tanning to opioid use was extreme.

“You would have people giving up their family lives to get access to sunshine, you would have people who lose their jobs because they spend their day on the beach, people would maintain UV-seeking behaviour to the detriment of their everyday life,” David Belin of the University of Cambridge told the BBC. “British people would go on holiday to the south of France and would never come back.”

This is not the first time researchers have speculated about tanning addiction.

The Skin Cancer Foundation, a nonprofit, called tanning “the new form of substance abuse.” In 2006, a similar study of a small group of human tanners found similar results to the Harvard research.

Though the organization did not mention tanning addiction, sun lamps and tanning beds earned an FDA warning last month.

The good news: Sunscreen may prevent a tanner with golden shoulders from becoming “The Man with the Golden Arm.”

“While the effects of sunscreen have not been reported in this context, it does appear likely that sunscreen use would protect against UV-induced addictive behaviors,” according to the study.