Pitfalls lurking amongst autumn beauty

Ted and Rachel Santi relaxing under a horse chestnut tree.

Horse chestnuts by name – but not even the horses will eat them.

“Only deer and wild boar can eat them because of their toxicity,” says Ted Santi of Gate Pa. But all this valuable information was gathered with hindsight, and too late to save wife Rachel from an unfortunate and unpleasant encounter with horse chestnuts.

“She woke me early one morning last week to tell me she was feeling quite ill, quite nauseous,” says Ted. He was a bit panicky and rang 111. A short time later Rachel was in A&E at Tauranga Hospital.

The day before Ted, Rachel and some Filipino friends had been taking in the autumn wonder at McLaren Falls in the Kaimai Range. “We saw these brown things on the ground and they looked like chestnuts. It  was late in the season and they’d shed their distinctive green spiky husk.”  The husk makes them look like a miniature flail, a medieval weapon of war.

 So the friends gathered what they thought were chestnuts and took them home. Oven roasted at 180 degrees for half an hour. “We had some three weeks ago and they were great,” says Ted.

Sweet, edible, mahogany brown chestnuts are not only non-toxic but are an incredibly healthy snack - low in fat, high in protein, gluten-free, high in vitamins and fiber, and, above all, delicious. Except these weren’t chestnuts.

These were bitter, had a distinctive sour taste and they made Rachel ill. And in the recesses of Ted’s mind there was something called a horse chestnut. “I remember them from my childhood – horse chestnuts or conkers.”

Out of their husks, horse chestnuts and ordinary chestnuts look similar, dangerously similar.

Tauranga Hospital’s Dr Derek Sage says saponins in the horse chestnut are gastrointestinal irritants. “Symptoms may include nausea, vomiting, diarrhoea, and abdominal pain. Serious toxicity is not expected and fatalities in humans have not been reported.” So Mrs Santi was never in danger. Although she’d had a nasty brush with horse chestnuts.  

Large ingestions may cause gastroenteritis with a risk of haemorrhage which is very rare, dehydration, and electrolyte imbalance.

While Ted Santi wisely got his wife to hospital, no specific treatment would normally be required following accidental, acute exposures. “There is no specific antidote,” says Dr Sage. “Treatment, if required, would be symptomatic and supportive. Mild gastrointestinal upset can be managed at home.” But larger consumptions may cause more severe gastrointestinal symptoms and warrant monitoring of fluids and electrolytes at hospital.

 “The medical emergency eventually passed,” says a grateful Ted. But he suggests there’s a lesson for everyone. “If you are unsure, don’t pick it up and don’t eat it. But if you do roast them up and they taste bitter, then don’t swallow it.”

There are also visuals checks. The edible chestnut is easiest to spot in its husk which is spiny and needle-sharp. The toxic, inedible horse chestnut, or conker,  has a husk that is much smoother, with only a few warts. The actual fruit of the edible chestnut has a point or a tassel, the inedible one has no point – it is smooth and rounded.

“My wife is just fine now thank you” says Ted Santi. But he still has a concern.

“Not many would know the difference between a sweet chestnut and a horse chestnut. And these horse chestnuts are lying around in a very public place and are a menace. Should there not be signs identifying the toxic fruit and advising people not to eat it?”

The Tauranga City Council has put responsibility back on park users. “If you are going to forage for food or nuts, it is important that you identify what you are planning to eat so you can be confident it is safe,” says the TCC’s Warren Aitken. Although it wishes Mrs Santi well.

At the same time Ted can understand why the horse chestnut trees are at the park. The stunning orange through to deep red leaves make the horse chestnut tree the very essence of autumn. And during spring there are clusters of pretty white or pink flowers.

How can something so beautiful be so nasty? But regardless of the Santi’s nightmare experience the horse chestnut trees are worth a trip up the Kaimai Range.

Subscribe to our weekly Newsletter