Saturday, December 2, 2023

Alzheimer’s-fighting daffodils trialled in high country

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The soggy cold springs in the high country are far from ideal growing conditions, but stressing the plants at elevation is thought to boost its health benefits.
Unlike cattle, sheep don’t eat daffodils, another point in high-country sheep farms’ favour when it comes to growing the flowers for their medicinal properties.
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By Delwyn Dickey for Our Land & Water

A key ingredient in Alzheimer’s medication could come from daffodil crops grown in South Island high country. Five Canterbury and central Otago high-country sheep farms are growing trial plots of daffodils on different soils, from sea level up to 650m. 

The soggy cold springs in the high country are far from ideal growing conditions for the daffodils, but stressing the plants at elevation is thought to be behind them to producing more galantamine, an alkaloid substance that helps raise the levels of the chemical acetylcholine in the brain. 

This chemical is lower in people living with Alzheimer’s. Raising levels eases symptoms like memory loss while slowing down the disease’s progression. 

Though not a cure, one drug on the market that includes galantamine has already been shown to ease symptoms associated with the disease. It is one of few drug options available to treat the growing number of people who live with dementia connected to Alzheimer’s disease.

Galantamine can be found in many different plants, said crop technologist Nick Pyke of Leftfield Innovation. China and Bulgaria are also looking at extracting it from different plants. But these don’t produce as much of the compound, with the plants killed off at harvest – unlike the perennial daffodils, he said. 

Daffodil production has been underway for a number of years on high-country sheep farms in Wales, as a joint venture with Agroceuticals. But for year-round production, a southern hemisphere source is also needed. 

Pyke came on board with the project after a chance meeting with a representative of Agroceuticals at the National Agricultural Fieldays last year. This has now led to bigger trials getting underway, with funding through Our Land and Water’s Rural Professionals Fund.

Finding the conditions for the highest levels of galantamine is the reason the South Island trial plots have been planted at elevations from sea level up to 650m. 

“Welsh production has been limited to about 300m above sea level,” Pyke said, “so it’s not known if higher elevations are beneficial.”

There are limited options for sheep farmers looking to diversify in the rugged high hills and as sheep don’t eat daffodil plants, unlike cattle, this could see the therapeutic plant easily integrated into current sheep farming systems. 

Small plot trialling in New Zealand’s southern high country has already shown commercially viable amounts of galantamine can be produced. Some varieties of daffodil carry higher levels of galantamine.

Perennial bulb species like daffodils store energy from the sun in their bulb for the following year’s growth. Harvesting early every year, before they die down naturally, affects their ability to store energy for the following spring. With this in mind, a gap year from harvest is expected to be needed at some point to regenerate the bulb, said Pyke. They are looking at a break with no harvest after five years of production. 

“It will take several years before we know if this project is going to be an option for farmers, with potential for small-scale production possibly at year three.”  

Wakatū Incorporation in Nelson has experience with extracting bioactive substances and may be processing the plants should the cropping side of things get off the ground, Pyke said. 

A cropping co-operative with farmers focusing on long-term sustainability, and working alongside Wakatū is the aim, he said. 

Should all go well, some serious propagation will be needed to get the numbers of bulbs up to the amount needed for large-scale planting.

The dementia drugs market is likely to be worth around $60 billion globally by 2030 –  so the future could soon look bright  yellow  in spring for some high-country farmers. 

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