Back in the 1950s many Jamaicans believed that drinking a tea made from the leaves of Periwinkle (Vinca major) could help control their diabetes.

Vinca major Vinca major leaves and flower

In time a governess who wintered in Jamaica heard about the bush tea and took some leaves back to  Toronto to her doctor. This doctor happened to be the brother of Dr. Noble who worked with Dr. Banting, the discoverer of insulin. Dr. Noble brewed the tea and fed it to rats. The tea killed the rats but did nothing to their blood sugar.

However the “young laboratory technologist, Halina Czajkowska, shyly confessed that she’d also counted the rats’ blood cells, even though she’d been asked only to measure sugar. Vinca had destroyed white cells and bone marrow, she reported. It might kill cancer.”

So Vinca tea turned out to be unable to control diabetes but it could stop cancer!

Now it took 15 tons of dried Periwinkle leaves to produce 1 ounce of the active ingredient, Vinblastine, so Dr. Noble ended up growing a supply in his own greenhouses.

When combined with other agents, doctors discovered that Vinblastine cures 90% of testicular cancers. Used with other drugs, the Vinca agents allow 98% of patients with Hodgkin’s Lymphoma to live 5 years.

Then they discovered another ingredient in Vinca which they called Vincristine. Vincristine along with steroids has become the treatment of choice for Leukemias in children.

Today there’s another bush tea – from Guinea hen weed – that shows promise. This time another Jamaican doctor, Dr. Williams, has taken out an international patent for dibenzyl trisulphide, (DTS), the active ingredient of Guinea hen weed.

Dr. Williams published his paper in the West Indian Medical Journal detailing the effects of DTS on different cancers. He claimed that it caused cancer cells to die (apoptosis) in lab experiments against breast, lung, bladder, prostate and brain cancer. However, he has not used it in human subjects as yet.