Plants have been used as medicines throughout history and studies on wild animals show that they also instinctively eat certain plants to treat themselves for certain illnesses.
Though previously thought to be over harvested due to high demand of herbal medicine globally, scientists now warn that the expanding herbal products market is now highly threatened by climate change more than ever before.
According to Dr Lou Verchot, a senior scientist at the Centre for International Forestry Research (CIFOR) planting of exotic trees in disregard to the indigenous species could lead to extinction of medicinal plant species worldwide.
“Scientists and university researchers must now embark on efforts to preserve both indigenous plant populations that are highly valued for their medicinal value besides planting exotic trees to sustain traditional medicine,” Verchot observes.
He notes that whereas planting of exotic trees is of great significance to conservation of forests and biodiversity, such trees lack the medicinal efficacy needed to sustain traditional medicine.
Speaking at the second World Agroforestry Congress in Nairobi, Dr Verchot attributes the poor health standards of people in rural areas to the demise of some valued trees that communities have relied upon from time immemorial as medicine.
A consultant on animal production systems in environment with the International Development Research Centre (IDRC) in Malaysia Dr. C. Devendra wants scientists to define medicinal trees and embark on their protection to help save livestock.
Dr. Devendra warns that the demise of indigenous trees is likely to cause untold suffering to livestock and animals since drugs used in their cure comes from the natural products.
“Global warming is contributing immensely to the depletion of useful plants that are used in herbal medicine,” says Dr. Michael Odotte, a virologist and inventor.
Dr. Odotte warns that unless conservation of indigenous tress is done in botanic gardens at home and institutions, herbal medicine is soon not going to be lucrative business.
He says some species that could to be found in certain areas are getting extinct due to wanton cutting of trees for charcoal burning, timber and lack of rainfall.
“Stinging nettles (Utica masaica), a common herb used in the HIV Aids management that is only found in Nyanza Province, particularly in Rachuonyo District is no more,” he notes.
This worrying climate change is forcing some species like tylosema fasioglemisis (ombasa) to develop short maturity seeds with some having one or none instead of 10 inside a pod.
The Chairman of the National Council of Associations for Alternative, Complementary Medicine Research (NCAACMR), Dr. Stephen Odongo observes that hot climate makes herbs in certain areas very bitter compared to the ones in cooler areas.
Odongo says that the conditions makes it difficult for people living with HIV who rely on herbal medicinal concoctions regularly to remain stable.
“Many people believe that because medicines are herbal (natural) or traditional they are safe,” Odongo says.
From his assessments, patients’ report that the herbs turn bitter in hot weather, forcing them to skip taking the medicine.
According to the World Health Organisation (WHO) herbal medicines are the most lucrative form of traditional medicine, generating billions of dollars in revenue.
In some Asian and African countries, 80 per cent of the population depends on herbal medicine for primary health care as it treats various infections and chronic conditions.
More than 100 countries have regulations for herbal medicines treatments which form the most popular type of traditional medicine, and are highly lucrative in the international marketplace.
WHO indicates that annual revenues in Western Europe reached $5 billion in 2003-2004, in China sales of products totaled $14 billion in 2005 while Brazil earned $160 million in 2007.
WHO attributes that herbal medicine has been used for thousands of years with great contributions made by practitioners to human health, particularly as primary health care providers at the community level.
“It has maintained its popularity worldwide. Since the 1990s its use has surged in many developed and developing countries,” WHO says on its website.
Climate change is a global phenomenon. Increase in population interferes with nature, leading to increased demand on limited resources and this impacts negatively on the environment.
Herbal materials are collected from wild plant populations and cultivated medicinal plants. The expanding herbal product market could drive over-harvesting of plants and threaten biodiversity.
Currently biodiversity treasures and rich traditional herbs provide rich source for discovery and patenting of new drugs in the market.
Nearly 40 per cent of the new drugs approved in the United States are directly derived from natural products.
According to scientists, global climate change could ultimately lead to loss of key medicinal and aromatic plant species.
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