When I graduated from nursing school exactly 30 years ago, my brother presented me with a tombstone of an ancient medical text he found while combing the aisles of a used book store.  It’s entitled “Library of Health” and it was published in 1916.  The hefty tome has 1,774 pages and the front cover bears the inscription: “You can do nothing to bring the dead to life but you can do much to save the living from death.”

One of the most fascinating aspects of working in healthcare is seeing the sweeping changes that shift medical practice as newer research develops. It’s not a science set in stone.  Flipping through the yellowed pages of my 1916 text is both a history lesson and hilarious “blast from the past” entertainment.  Under the chapter titled “Diseases Peculiar to Women”, for example, we learn that “the greater majority of women are constipated”, due to various causes including “inconvenient privies”.  As a neurology nurse, my personal favorite diagnosis moniker at that time was “dropsy of the brain” found in the Nervous System chapter, most likely referring to hydrocephalus.

Curiosity led me to find a reference to cannabis, all of two paragraphs in the medicinal plant chapter.  Although the author warns that frequent use results in “permanent mental damage”, he admits that medicinal purposes include the quieting of spasms, mental calmness and that the tincture can treat coughs, restlessness and delirium.

Poking around in the history of cannabis is like putting a giant puzzle together.  The pieces come from many, many places and are scattered across thousands of centuries.  To understand cannabis and its medical applications, a big-picture view is enlightening because it points to the efficacy of a plant long-known for its healing properties.

By most accounts, the earliest records of medical cannabis use date back to about 2700 B.C. in China.  Already using hemp for cloth and rope as early as 4000 B.C., the Chinese made a tea made from cannabis leaves to treat conditions like gout and malaria. According to legend, the emperor Shen Nung (considered the Father of Chinese medicine] discovered marijuana’s healing properties as well as those of two other mainstays of Chinese herbal medicine, ginseng and ephedra. In drug recipes compiled in 1 AD [Pen Ts’ao Ching], based on traditions from the time of Shen Nung, marijuana is recommended for more than 100 ailments, including rheumatism, malaria, and absentmindedness.

Other regions of the world followed China’s lead in cannabis usage.  We know from medical papyri that the ancient Egyptians (circa 1000-1700 BC) used cannabis to treat foot and eye problems, even hemorrhoids.  In Greece, the first written record comes from Herodotus, who wrote in 500 B.C. that Scythians, a group of ancient Iranian nomads, took vapor baths using marijuana.  There’s written mention of using cannabis for ridding oneself of tapeworms, nosebleeds, and inflammation.  A Greek physician named Pedanius Dioscorodes (circa AD 40-90) was a Roman army doctor who studied plants and included cannabis in his book titled De Materia Medica (On Medical Matters). Published about AD 70, it became the most important medical reference of its time. Dioscorides stated that the plant produced a juice that was used to treat earache and “suppress sexual longing.”

But it’s in India where medicinal usage became more creatively concocted and also integrated with spirituality.  Cannabis was mixed into special drinks used both for enjoyment and for medical reasons. One of the most popular of these drinks is bhang and is still made today — a mix of cannabis paste (made from the buds and leaves), milk, ghee, and spices.  If you view photos of people making bhang, it looks like a green-colored smoothie.

In the Hindu text known as the Atharvaveda which means “Science of Charms,” ancient Indian writers refer to bhang as one of the “five kingdoms of herbs… which release us from anxiety.” As the drink gained popularity, it was purported to make people mentally better as well as removing “wind and phlegm. “  More practical uses came along in later writings like the “Sushruta Samhita” (an Ayurvedic medical text circa A.D. 300) which includes treating pain, insomnia and headaches. The line between magic and real science is pretty blurry here but history shows that the drug had been largely incorporated in medical life in India for thousands of years.

Fast-forward to the Middle Ages where cannabis is readily found on the shelf of working herbalists and healers.  One such herbalist, Nicholas Culpeper of Great Britain, wrote in his 1652 The English Physitian (sic) that hemp extract ‘”allayeth Inflammations in the Head, eases the pains of the Gout, Knots in the Joynts, [and] the pains of the Sinews and Hips”.  I love this! Another British scholar Robert Burton suggests cannabis as a treatment for depression in his 1621 book The Anatomy of Melancholy.

The standout in the long cast of characters from cannabis history is William O’Shaughnessy, an Irish physician who some credit as the catalyst for medical cannabis usage in modern times. In 1833 O’Shaughnessy took a job with the East India Company to work in Calcutta as an assistant surgeon, beginning his lifelong interest in Indian medicine.  There the Irish doctor learned about therapeutic effects of cannabis from his interactions with indigenous people.

To test the claims made by locals about cannabis O’Shaughnessy undertook a range of experiments. He started his research on animals such as mice, rabbits, and rats, then moved onto humans. He recorded and presented case studies of patients suffering from ailments such as Cholera, rheumatism, hydrophobia, tetanus, rabies and convulsions in infants. Eventually he published The Bengal Pharmacopoeia in 1844 which included a 25-page section on cannabis.  Other Western doctors took note, igniting a flurry of studies.

It strikes me that history, at least the history of cannabis, is beginning to repeat itself.  So many years ago, cannabis was revered for its healing properties, then it was vilified, and now is revered again, at least in some circles.  Last week while on a business trip, I picked up a copy of USA Today (a staple of chain hotel lobbies).  The cover story was titled “Medial Marijuana Used Pot’s Emotional Connection to Spread Nationally” and covered how our view of this plant, once the butt of Cheech and Chong routines, has changed and become a credible healthcare product as more states allow medical use.

When I look back at the colorful history of cannabis, the past purposes of uses seem both ridiculous (sexual diminishment) and pragmatic (pain, mood disorders).  But any science, medical or otherwise, must take what it knows from any given point of time and go from there.  We adjust our thinking as the old tenets fall away and new textbooks are written.   And always we have to keep an open mind about what we think we know and what’s really true just as our ancestors did.  That part of history bears repeating.