Ginkgo – Living fossil or potential wonder drug

With Maggie Chaplin “Ginkgo Biloba supports mental focus and memory” reads the label on a bottle of widely available herbal tablets. We could probably all do with a bit...

With Maggie Chaplin

“Ginkgo Biloba supports mental focus and memory” reads the label on a bottle of widely available herbal tablets. We could probably all do with a bit of help with our mental focus and memory, and a preparation with a name like ginkgo biloba is bound to have some special properties isn’t it? Extracts from the ginkgo tree have been used medicinally for thousands of years and its popularity shows no sign of waning. Ginkgo is one of the most frequently bought over-the-counter “natural” preparations currently available, and that’s no surprise when you realise the variety of claims made for its benefits, not just to boost brainpower. But does it work?

Ginkgo was apparently used to treat asthma and bronchitis as far back as 2600 BC and more recently it has been tried as a remedy for dozens of different maladies ranging from altitude sickness to haemorrhoids. Efficacy is mostly inconsistent. More convincing are the studies that suggest that ginkgo extract  has a beneficial effect on brain function by improving blood supply, and that it may also have antioxidant properties, hence the claim that it can enhance concentration and memory. However, results of even these researches are often conflicting, although investigation into the possible benefits of gingko in treating Alzheimer’s and other dementias is ongoing.

So, what is ginkgo apart from being the source of a potential cure-all? The ginkgo is an amazing and unique tree. It’s a distant relative of the conifers and is often referred to as a “living fossil” because geological evidence shows that similar trees flourished when dinosaurs roamed the earth more than 200 million years ago.

The plant originates in China and Japan and “ginkgo” is a corruption of its Chinese name. “Biloba” refers to the unusual shape of its leaves, which resemble those of the maidenhair fern – hence its alternative name, the maidenhair tree. There is doubt as to whether there are any natural trees in the wild today, and its survival may be due the fact that it’s considered sacred and has for thousands of years been cultivated in the vicinity of eastern temples. Ginkgos can live for an incredibly long time – the oldest living specimen is believed to be around 3,500 years old.

It’s also a very resilient species. Six trees growing within a radius of 2 km of the site of the atomic bomb dropped on Hiroshima in 1945 survived, whilst almost all other living things in the area were destroyed. It’s fitting that the ginkgo is the official tree of Japan’s capital Tokyo, whose symbol is the ginkgo leaf.

In China the ginkgo has been a staple of traditional medicine for centuries, and with the growing western market for ginkgo preparations, the Chinese cultivate acres of hedges of ginkgo to meet the demand for leaves for use in teas, tablets and cosmetics. Mature trees are also grown by the hundred for the seeds, which are roasted and eaten as a delicacy in China. Despite its age-old significance in Eastern culture, Ginkgo didn’t come to Europe till the early part of the 18th century when the first seeds were imported and grown in Britain. It has proved to be a very versatile tree.

As well as having a reputation as a medicinal source, ginkgo has all the right qualities for an urban tree and is now often to be seen in city parks and arboreta – there are several at Batsford – and for landscaping town streets. There’s at least one in Chipping Norton. Because it’s relatively slow growing and rarely tops 100ft it doesn’t dominate its surroundings, unlike the often-planted city tree, the lime. It’s also pollution tolerant and resistant to disease and insects, so you can park under it without your car getting covered in sticky aphids, neither does it sprout masses of unsightly water shoots round the base as limes do. The leaf canopy provides good shade and although when its twigs are bare in the winter you probably wouldn’t give it a second glance, once the buds begin to open in the spring, the ginkgo show starts.

My first encounter with a ginkgo tree was when I was at university and I was introduced to one growing in the college grounds by a friend who was a botany student. She raved about its unique history, which I found fascinating, but I was also struck by its beauty. It was a clear November day and the unusually shaped leaves shone radiant gold and orange in the autumn sunshine. I resolved to have one.

It was many years later that I had a garden big enough to plant a tree in, and then only just. When I moved house, my little ginkgo sapling had to come with me. It resented the disturbance and though I chose a sunny spot and gave it space to grow, it didn’t budge. It doesn’t help that my current soil is heavy clay, and for years it just sat there and did nothing. The shrubs near it weren’t so fussy and grew to dwarf its puny presence. I resigned myself to having the only stumpy ginkgo in Oxfordshire. Fortunately it didn’t die either. Then a couple of years ago it must have managed to push its roots into the clay and it suddenly spurted into growth. It’s now a respectable 12 ft high, although its cousin that inspired me is probably 100ft tall by now.

I got mine for its (potential) good looks, but if you fancy having a ginkgo as an exotic nut tree, there are things to bear in mind. As well as a fair bit of space, you’ll need a male and ideally two female trees, and patience, lots of patience. Ginkgos don’t do anything in a hurry. They’ll be at least twenty and maybe more like forty years old before they even think of flowering. (My stripling’s nearly thirty, but it’s had a hard life). They or their close relatives have been around for about 200 million years so what are a few decades in that timescale? 

You’ll also have to have a good deal of trust in your garden centre. The chances are you’ll buy juvenile trees, and the sex is important – not only for breeding purposes. If your only interest is in an ornamental tree, you still need to know – and definitely go for a male. Female ginkgos stink! The fruit of the ginkgo is orange and about the size of a ping-pong ball – and in this case it’s mostly pong. The odour of the fruit pulp has been likened by some to that of dog poo, and by others to the smell of vomit, neither of which endears it to garden culture. The edible kernel is inside a thin shell in the middle of this smelly mush.

 You can’t tell the sex of immature trees and at one time it was rather hit and miss and some female saplings found their way into urban environments, only to be considered very unwelcome years later when they started to fruit. Having your car pelted by smelly, squishy little bombs is considerably worse than a coating of sticky aphids. Fortunately modern cultivation methods mean that most of the ginkgos sold today are clones of male trees.

Ignoring the potential nut harvest, the decision to set up your own pharmaceutical source shouldn’t be taken lightly either. There are safety concerns. No part of the ginkgo should be consumed raw. The pulp of the fruit is particularly toxic – although the smell should put anyone off accidental ingestion – and it can cause severe allergic skin reactions on contact, so processing may be tricky. The nuts too must be roasted before eating – fresh seeds could kill, which is worrying when you find that raw ones are readily available via the internet.

It’s ginkgo leaves that are the main commercial crop, but even they need careful preparation. Perhaps the message should be, if you’ve got the space, plant a ginkgo tree for its beauty of form, breath-taking autumn colour and unique history, but if you seek the medicinal benefits that ginkgo may provide, buy a properly prepared standardised extract and be safe.

Thousands of people worldwide regularly take ginkgo in one form or another and are convinced of its value. There’s much anecdotal evidence for the effectiveness of these preparations in treating a variety of ills, but there’s a shortage of concrete scientific

back-up for these claims.To quote Sir Muir Grey CBE, visiting Professor at Oxford University and internationally renowned medical authority: “I have found no evidence to convince me of the need to take gingko. There may be benefits, but it is better to take 3,000 extra steps a day, and if you want to keep mentally active take up sudoku.”

So, I’ll not be nibbling the leaves of my ginkgo tree any time soon and it’s back to walking the dog, then settling down with the puzzle page of the newspaper – if I can remember where I’ve put it . . .