Mon | Dec 10, 2018

Dr Bertram Reid | Perhaps periwinkle! - Jury still out on ‘bush tea’ in the treatment of diabetics

Published:Sunday | January 7, 2018 | 12:00 AM
Periwinkle used to beautify a home.

In many developing countries that I have been privileged to visit there is no ready access to medical care. As a result, many people resort to medication by 'bush tea'.

The predicament is not unlike that into which I was born in 1934 in Coleyville, Manchester. Teas from leaf-o'-life, 'surosee' (cerasee), guinea hen weed, etc, were administered for fevers, colds, bellyaches, worms and other illnesses.

At age six, I nearly severed my left middle finger while mishandling a machete. The nearest hospital was in Mandeville, 15 miles away and we didn't have a car, so my grandmother attended to the wound. Whatever she applied, before bandaging the finger, restored it perfectly.

That was a good story; but I also have a sad story. At a conference on malaria in Nairobi (Kenya) in 2009, a social worker told us about the high incidence of death among pregnant women who came down with malaria.

Mosquitoes are attracted to blood, and pregnant women are wonderful sources. Reliable bush teas may help the mother's malaria, but the chemicals in the drink are fatal for the foetus. This tragedy frequently resulted in death of the mother as well.

Bush teas are understandably a first resort when medical care is not available. Indeed, faced with a diagnosis of cancer, diabetes or the like, one can be forgiven for placing faith in anecdotal cures. We know the pharmaceutical industry can now discover truth from fiction; but who has time to wait?

The dilemma can be exemplified by my own father who was diagnosed with diabetes in the 1930s and lived with the ailment until the then ripe old age of 76. Insulin was available; but in those days (1930-1950), the drug had to be isolated from the pancreas of dogs and hogs, and as a result was expensive, and well beyond the budget of a rural schoolteacher.

But my father had faith in a tall glass of periwinkle tea. Monitoring the sugar in father's blood was complicated. Devices for testing a drop of blood on the finger, or a dipstick for testing urine were decades away.

My father had to test his urine by an elaborate procedure that was the first chemistry experiment I witnessed. An intricate procedure involving a blue solution, and a spirit lamp, both available at 'Miss Bailey's Drugstore', were involved in the experiment.

A drop of fresh urine was mixed with the blue solution which was then heated. If the solution changed from blue to brown, his 'sugar' was high and appropriate steps were required. Certainly another glass of periwinkle tea would take care of the problem.

Our family physician was Dr Ernest Douglas whose son, Dr Lawson Douglas, is one of our prominent surgeons. Lawson and I have been friends for all of our 83 years.

When I told him about my father's faith in periwinkle tea he recalled that his father also drank a nightly glass of the tea, which, he believed, saved him from the cursed diabetes that had afflicted all his siblings.

It is therefore most likely that when 'Dr Ernest' diagnosed my father with diabetes, he prescribed a daily glass of periwinkle tea.

My father dieted rigorously. He was 'thin as a rake' throughout his life He eschewed delicious, fatty pork in favour of fish, fish and more fish which, in the 1930s, arrived twice each week on the back of the fishmonger's motorbike.

Instead of our delicious hard dough bread, he chose whole wheat bread, two loaves of which arrived from Kingston once each week.







He must have read that exercise was good for diabetics and so, at a time when grown men in Jamaica did not exercise, he embarrassed his children by standing on the veranda, swinging away with his home-made dumb-bells every morning.

In view of the dieting and exercising, was the benefit of periwinkle tea real or imagined? Probably the theory was that the exceedingly bitter, astringent tea would 'neutralise' the sweet 'sugar'.

Scientific investigations of periwinkle are therefore revealing.

To begin with, my father's urine 'test' was unreliable. The only 'sugar' of interest to the diabetic is glucose, but this belongs to the large family of carbohydrates knows as aldoses.

Our bodies are full of them and they would have given the brown colour, which in my father's case was a false/positive. The poor man did not need all that periwinkle tea.

The periwinkle plant belongs to the class of shrubs known as vinca which thrive in the tropics. The variety with white flowers (vinca rosea) is used for the tea. At HEJ Research Institute in Pakistan, I saw acres of the shrub being cultivated.

I learnt that in developing countries, vinca rosea extracts are used for diabetes treatment and, as with most 'bush teas', for the treatment of cancers.

In the 1950s, a doctor in Jamaica sent a parcel of Madagascar periwinkle leaves to his brother (also a physician) in Florida. The brother sent it to a biochemist at Canada's University of Western Ontario who found that an extract caused a diminution of the white blood cells of rats.

Could this be a treatment for leukaemia, which is the abnormal increase in white blood cells.

Extensive collaboration over 10 years with the pharmaceutical company Eli Lilly of Indianapolis led to isolation of several potent alkaloids, specifically vinblastine and vincristine, which are now used for treatment of a variety of cancers.




But what about diabetes? The Eli Lilly scientists did not find a shred of evidence for any anti-diabetic activity.

In view of the fact that my diabetic father had lived to 76 relying heavily on periwinkle tea, I was concerned that the discovery of the novel, potent anticancer drugs might have detracted from pursuing the anti-diabetic potential of the tea.

In the late 1990s, I was consultant to a diabetes research company. We collaborated to reopen the search for a diabetes/periwinkle connection. The result was still negative.

Several questions arise.

1. Did the periwinkle tea inhibit cancers from developing in my father and in our many neighbours who also had 'suga', and relied on him to test their urine?

2. Dr Ernest drank a nightly glass of periwinkle tea. He lived to 67 without diabetes or any cancers. Did the tea protect him from both diseases?

3. Could the other potent alkaloids in the tea have induced abortions in pregnant diabetics?

4. Since periwinkle definitely contains anti-cancer compounds, could local preparations of the plant be used instead of the expensive Big-Pharma products?

Dr Lawson Douglas and I were both born around Christiana 83 years ago. Lawson is not diabetic - but I am. We are both free of any cancers. Neither of us drank periwinkle tea. Maybe I should have. We may never know.

- Dr Bertram Reid is a past professor of chemistry at Duke University. Feedback: