Forest Healthcare
Tropical forests provide a vast array of substances used in healing and healthcare, worth an estimated $108 billion a year. More than a quater of modern medicines originate from tropical forest plants. For example the Rosy Periwinkle found in Madagascar is used to treat lukemia whilst the anit-malarial drug quinine is taken from the bark of the cinchona tree. With only 4% of tropical plants tested for their medicinal properties the rainforest could yet provide cures to many diseases.
By releasing water slowly to rivers, intact forests can also provide a steady service of clean water to local populations. Many tropical forest ‘goods’, such as medicines, foods and fuel, do not enter markets, but are extremely useful to local people who depend on forests for their survival. Forest goods and services therefore help marginalised rural populations to cope with times of stress such as climatic shocks and so provide a form of health insurance.
The wonders of the wild yam...
The wild yam has greatly influenced the social and medical traditions of millions of people around the world. Diosgenin is extracted from the rhizome (underground stem) and roots of the yam and it forms the basis of the modern birth control pill. Since its discovery in the 1930s, it has been the foundation from which a variety of human sex hormones have been produced. In Central and South America is was traditionally used to prevent pregancy, whilst in China it is used to treat liver conditions. Yam extracts have been found to reduce inflammation and pain, and relax stiff muscles, and so are useful in treating arthritis and rheumatism.
Diosgenin is a 'saponin', a plant steroid which protects plants from attack by slugs and snails, insects and microbes. It is used as a natural insecticide, and in many cultures across the world it is also used to stun and catch fish. Photo © Mimi Camp, www.rain-tree.com
Effects of Deforestation on Health
Undisturbed tropical forests can have a moderating effect on infectious disease. 40% of the world’s population lives in malaria infested regions. Heavily deforested areas can see a 300 fold increase in the risk of malaria infection compared to areas of intact forest.
Deforestation changes the local climate and hydrology, which affects mosquitoes, but perhaps more important are social processes facilitated by roads such as migration, creation of new communities, and increased density of existing communities, that can affect pathogen transmission.
72 per cent of emerging infectious diseases that have leapt from animals to humans, such as HIV, come from wildlife as opposed to domesticated animals. Recent examples include Nipah virus in Malaysia, and the infamous SARS outbreak in Guangdong, China, which practically shut down international travel in Southeast Asia in 2002. Reducing human impacts on tropical rainforests may help to reduce the chance of future diseases jumping from wildlife to humans.
Rainforest Concern (2008) Kid's Guided Tour of the Rainforest. (www.rainforestconcern.org/education_resources/resources_for_schools) Rainforest Concern, London.
