Traditional healthcare systems are based on significant local knowledge of medicinal plants. Traditional medicine is therefore often highly available and accessible to people in developing countries, and poor and marginalized people – especially those in rural areas –are often highly reliant on it.

Many pharmaceutical products are derived from tropical forest species; some of these products are now synthesized, but others are still collected in the wild. The economic value of traditional medicines derived from forest species (mainly plants) is considerable: the global value of the annual market for these products was estimated at US$60 billion in 2002.

Interest in traditional knowledge and medicine has grown in the last two decades, stimulated by the role of such knowledge in the development of new commercial products, including pharmaceuticals, herbal medicines, seeds, cosmetics, and personal care and crop protection products. Traditional knowledge is used in screening plants for medically active compounds.

The commercial users of traditional medicines (“bioprospectors”) are often companies and scientists in technologically advanced countries. Concerns have arisen in recent years about “biopiracy” – the unauthorized commercial use of genetic resources and traditional knowledge and the lack of sharing of the benefits with the countries and communities of origin, as well as the patenting of spurious “inventions” based on such knowledge and resources. In the case of traditional medicine, pharmaceutical companies have sometimes been charged with reaping unacceptably and disproportionally large benefits from the knowledge of forest peoples, many of whom live in highly impoverished conditions. Other more general threats to traditional knowledge and forest-based medicines are those posed by deforestation, forest degradation and over-exploitation, and the consequent loss of genetic diversity among therapeutic species, and the loss of traditional knowledge under fast-changing social and environmental conditions.

There is evidence that exposure to natural environments or green spaces has positive health impacts. Exposure to forests specifically has stress-reducing effects – possibly due to the recovery effect of viewing attractive or aesthetic forest landscapes, as well as the forest climate, light conditions and air composition (including essential oils).

Forest environments may also pose risks to human health. For example, people with frequent interactions with forests may be exposed to forest-related infectious diseases. Several emerging infectious diseases (EIDs), the incidence of which in humans has increased in recent decades and could increase further in the future, are associated with forests. The proximate causal factors in the emergence of EIDs include deforestation and other land-use changes, increased contact with forest pathogens among people lacking previous exposure, and pathogen adaptation. EIDs may be transmitted via non-human primate hosts or insect vectors, with a variety of intermediate hosts, including domestic animals.

The role of forests and forest management in the emergence of infectious diseases in humans appears to involve three separate but interacting dynamics:

1. land-use change and the expansion of human populations into forest areas, resulting in the exposure of immunologically naïve human and domestic animal populations (i.e. those lacking previous experience with microparasitic fauna) to pathogens occurring naturally in wildlife;
2. forest clearing and alteration producing an increase in the abundance or dispersal of pathogens by influencing host and vector abundance and distribution; and
3. the alteration of ecohydrological functions such as water infiltration, peak discharge and runoff, thereby facilitating the survival and transport of water-borne pathogens in watersheds and catchment basins.

These changes are often linked to forest clearing and increased edge habitat, the fragmentation of the forest landscape, and disturbance of the vertical structure and diversity of forest stands.

The virus that causes yellow fever is maintained in a transmission cycle involving arboreal monkeys and sylvatic (jungle) mosquitoes, and a frequent cause of outbreaks is the expansion of human settlements into forests. In many areas, malaria – which causes the largest number of deaths and disabilities of any infectious disease, by far (300 million–500 million cases annually, with a death toll as high as 2.7 million) – is transmitted by forest-associated mosquitoes.

Forests have other risks for human health, such as those posed by forest fires (and associated smoke hazes) and landslides. Forests may harbour dangerous wildlife and toxic plants and fungi. The stings and bites of forest insects, snakes and other animals may cause irritation, pain and, in some cases, deaths in humans. Some forest plants produce pollen, a major cause of allergies, pointing to a clear need to identify non-allergenic or low-allergenic trees and other plants when designing parks and managing urban forests.

The diversity of forest types, wildlife, disease vectors, human populations and cultures, and interactions among these factors, all affect human health. It has been projected that the incidence of disease in forested areas and elsewhere will increase as the climate changes.

People residing in and near forests typically obtain a considerable, although variable, amount of nutritious foods from forests – with poor people generally most dependent on such food. Trees provide a variety of healthy foods – such as fruits, leafy vegetables, nuts, palms, roots and tubers, seeds and edible oils, mushrooms and insects – that can diversify diets and address seasonal food and nutritional gaps. Forest foods contain proteins, fats, carbohydrates, vitamins and minerals, as well as phytochemicals such as phenolics and carotenoids. However, forests may not always be able to provide balanced diets, and some forest foods contain toxic compounds.

Forests provide a food safety net in case of food shortages, and they can mitigate food insecurity and malnutrition. Forest foods may provide nutrients not otherwise available, and they can help people survive famine, wars and drought.

Forests are genetic reservoirs of plants and animals with the potential to contribute to food security and nutrition in the future. Forests also supply numerous goods (and environmental services) that indirectly support the provision of food, such as poles (for supporting fruit trees or fencing crops), beehives and fodder.

More knowledge is needed on the nutritional values of forest foods. Nutrition education can play an important role in empowering rural populations, with the potential to generate tangible benefits for households and communities in achieving food security and nutrition, sustainable forest and landscape management, and health. There is a need to develop or adapt forest management practices that can conserve and make efficient use of food species. It is difficult to overstate the importance of the traditional knowledge of indigenous peoples and local communities in gathering, hunting, managing and using forest foods and medicinal forest plant species.

Forests are important repositories of medicinal compounds in wild organisms, including some already-common foods, drinks and drugs (e.g. cocoa, cola nut and ginger). Forests are a rich reserve of compounds that can be used as pharmaceuticals and nutraceuticals.

Forest trees and other plants contain a wide variety of bioactive compounds with potential as anticancer drugs, antiatherogenic compounds, and antioxidants. Forest species contain alkaloids such as reserpine, quinine, quinidine, ipecac, ephedrine and caffeine, as well as antibacterial and antifertility compounds. Quinine and quindine, which derive from Andean forest trees in the genus Cinchona, have been the world’s main defence against malaria for decades, saving countless lives. The Madagascar periwinkle (Catharanthus roseus) is used in the treatment of leukaemia, Hodgkin’s disease and other diseases. Forest animals also provide a source of medicines, including toxins purified from venomous snakes, spiders, insects and scorpions.

There is a wealth of indigenous and local knowledge on forest medicines. Western science has confirmed the benefits of many such medicines, but the effectiveness of many other forest species, and their potential side-effects, are still unknown.

Demand for herbal medicines has increased in recent decades in both developing and developed countries; it has been reported that more than 4 billion people in developing countries use them, mostly the rural poor. An estimated 28 percent of plants on earth have been used medicinally, with the people of India and China the biggest users. For 65 percent of India’s population, traditional medicine is the only available source of healthcare, and it also accounts for about 40 percent of all healthcare provided in China.It is estimated that 70–80 percent of Africans consult traditional medical practitioners for healthcare. A study in rural Burkina Faso found that more than 50 percent of ill people used traditional medicines at some point in their treatment-seeking strategies.

It is difficult to determine the exact economic value of traditional medicines obtained from forests. The annual value of pharmaceuticals of natural origin has been estimated at US$75 billion. The annual value of medicinal plant exports from Nepal has been estimated at US$39 million–159 million, making it the country’s fifth most valuable export. The bark of Prunus africana (nearly all of which is obtained from the wild) was reportedly worth US$220 million to the pharmaceutical industry in 1999.

Considerable controversy surrounds the use of medicinal plants and animals. Issues include:

• the appropriation of traditional knowledge and forest genetic material by Western pharmaceutical companies;
• the utility of traditional and local healthcare knowledge; and
• the possible dangers associated with the use of traditional medicines (e.g. due to improper traditional drug formulation, poor practitioner training, or misuse due to the lack of knowledge of individuals in their use).

The efficacy of traditional medicines (especially in comparison with other healthcare options) should be considered, as well as the relative expertise of their practitioners. In many (perhaps most) places, there is little “quality control”, except where the medicines have become institutionalized, such as in formal ayurvedic colleges in India and similar traditional medicine centres in China. Many of the bioactive compounds in tropical forest plants are highly toxic if used in high doses.

People living in or near forests, especially in developing countries, often benefit little from the commercial development of medicines derived from forest species. The Nagoya Protocol of the Convention on Biological Diversity addresses the issues of fair patents, the distribution of profits, and the recognition of traditional knowledge in the pharmaceutical and botanical industries. Pharmaceutical companies incur significant costs in the discovery, laboratory research, processing and distribution of, and legal requirements, for, medicines. Nevertheless, many observers are troubled by the divergence in wealth between pharmaceutical companies and the communities who live in or near the forests from which the genetic material for medicines is obtained. Although one of the aims of the Convention of Biological Diversity is to protect benefit-sharing rights, the mechanisms in place to ensure this are often inadequate, especially in developing countries. Determining how profits should be divided and who should receive them is difficult, but many people consider that current arrangements are inequitable. Contributing to the sense of injustice is the oft-cited importance of using indigenous medical knowledge to narrow down the pool of plants to investigate from the vast diversity of forest species. 

The International Union for Conservation of Nature estimates that more than 20 000 species are used for medicine worldwide, and half of these are under threat of extinction. The use and sale of medicinal plants are often closely connected with threats to their survival.

Many medicinal plants were once harvested only by specialists; today, however, medicinal plants are an open-access resource, and many of the traditional restrictions that limited harvesting in the past are ignored. Traditional plants were protected in the past by taboos, seasonal and social restrictions on harvesting, the harvesting equipment, a lack of access to markets, and perceived toxicity; traditional practitioners also safeguarded medicinal resources by restricting the number of apprentices. Government regulations designed to prevent the overexploitation of medicinal plants tend to be less effective, however.

The traditional knowledge of local communities in gathering forest foods and medicinal forest plant species is not recorded to a sufficient extent. There is a need to balance the commercial exploitation of medicinal forest species for pharmaceuticals and the maintenance of local livelihoods. Developments in biotechnology may help protect valuable plant species from overharvesting. The rights of source countries and people need to be secured and adequate compensation systems developed. Accurate data on the contributions of medicinal plants from forests to human welfare is needed, as well as more information on medicinal plant production, trade and consumption.

It’s undoubtedly fair and necessary to recognize the role of women when talking about the health benefits that forests provide. In developing countries, it is mainly women who rely constantly on natural resources for their household livelihood. They have expertise on local plants, grass, fruits and biodiversity in general, and they know how to transform these raw materials into edible and medical products.

Some among the most important gender issues regarding this topic are:

• The recognition of the role of women in natural resource management. It is recognized that women have a different relationship with nature than men. This is particularly true in the developing world, especially in rural areas where women depend on natural resources for daily subsistence. Women are traditionally appointed as caretakers of the family and the household. They collect water, fuel, provide food and medicine, among other things. Due to their close relationship with nature, women have a vast traditional ecological knowledge on local biodiversity and play a significant role in sustainably managing species that risk extinction. They also monitor the health of forests. Nevertheless, they don’t play a significant and proportionate role when it comes to high level decision-making positions, they rarely participate in decisive discussions, they hold few land tenure and rights, and they are not involved in the policy and decision-making process. It is, thus, necessary to acknowledge the importance of women in forest management, for the sake of both forests and communities.  
• The protection of traditional knowledge. Traditional knowledge about medicinal plants is held by communities and cultures over generations, and has deep cultural and economic significance. It is not static, but rather dynamic and it is usually transmitted orally. Such communication includes a variety of literary, artistic and scientific works, medical practices, agricultural techniques, etc. With regard to biodiversity, knowledge is transmitted about healing, agricultural and sacred properties of plants and animals, as well as about the quality of cultivation and processing methods. As noted above, women have a large role in keeping traditional knowledge alive, e.g. tribal women in India know and regularly use almost 300 forest species for medicinal purposes. It’s this knowledge that ensures survival, especially during crisis, generating meals and medicines. As traditional knowledge is a valuable tool for forest dwelling communities, there is a need for widespread action that challenges gender bias and stereotypes at a local level, and challenges powerful stakeholders, such as pharmaceutical companies, at a more national and international level.

The role of women in markets.

Another issue affecting women is the disproportionate income generated by the exploitation of natural resources, especially in developing countries. At a local level, despite women being the ones to collect plants, grass and other species, and knowing how to transform them into precious resources, they have limited access to the main markets (e.g. national and export markets). Barriers that women face when trying to access the markets could be addressed in a twofold manner: 

1. by contrasting the rigid gender stereotypes that prevent women’s products having the same value as men’s. and empowering women by creating women-held cooperatives; and
2. by involving women in policy-making decisions, both through reaching more gender balanced committees, and by including a gender perspective in the policies.
   

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