Biodiversity plays an indispensable role in sustaining human health by containing and preventing the occurrence and spread of diseases, enhancing mental and physical wellbeing, and providing resources that enable innovation in modern medicine as well as the maintenance of traditional systems of medicine.

Disease prevention

Recent research is increasingly focusing on the significant role played by the loss of biodiversity and natural habitats in the rise of several non-communicable as well as infectious diseases, including global pandemics.

Environmental microbial diversity and non-communicable diseases (NCDs)
NCDs are on the rise globally, and Europe is the most affected. NCDs cause 80% of the disease burden in the EU and are the leading cause of avoidable premature deaths. There is mounting evidence that many  (autoimmune diseases, type 1 diabetes, multiple sclerosis, allergies, eczema, asthma, etc.) can be linked to depleted microbial diversity in the human microbiome. Recent research also points to links between altered microbial diversity and mental disorders. The diversity of bacteria, viruses, fungi, archaea and protozoa contained in microbes, and microbial interaction within the complex human microbiome, influence both the physiology of disease and susceptibility to it. Microbial interchange with environmental microbial ecosystems diversifies the human microbiota and helps regulate the immune system as well as enhances adaptability of human microbiota (in digesting new foods, for instance). Failing immunoregulatory mechanisms, partly attributable to reduced contact with the natural environment and biodiversity, can also lead to poor control of background inflammation.

Furthermore, many mechanisms that regulate our immune systems were co-created via human co-evolution with other organisms. Some of these mechanisms have negative health effects and are eliminated by modern medicine, especially in high-income settings like Europe. This emphasises the importance of the immunoregulatory role of the microbial environment especially in these settings.

The human and financial costs of NCDs are high and expected to grow, also considering the EU’s ageing population. Moreover, people suffering from NCDs can be more affected by other diseases, as COVID-19 has shown. The Steering Group on Health Promotion, Disease Prevention and Management of Non-Communicable Diseases provides expertise to the Commission on developing and implementing activities for health promotion, and NCD prevention and management. The EU Green Infrastructure Strategy promotes increased exposure to nature and its attendant benefits for NCD mitigation.

Infectious diseases
Infectious diseases cause over a billion human infections and millions of deaths per year globally. They also affect plants and animals, undermining food and water supply, with additional impacts on human health. Two-thirds of known human infectious diseases are shared with animals, and the majority of recently emerging diseases are associated with wildlife. Anthropogenic practices such as land-use change and antimicrobial use damage ecosystems, leading to increased infectious disease transmission risks and impact. For instance, loss of natural habitat forces wild animals into human-inhabited areas, facilitating the spread of zoonotic diseases (these constitute 60% of emerging infectious diseases, of which 72% originate in wildlife). At the same time pathogen dynamics are also changing: global travel, climate change and antimicrobial use are rapidly affecting pathogen movement, host ranges, and persistence and virulence. Beyond direct infection risks, such changes also impact food security and medicine. Whilst high-biodiversity areas may have more pathogens, biodiversity also protects against pathogen exposure via regulating functions such as host species competition. Infectious diseases threaten wild and domesticated species, as well as the humans that depend on them, and pathogen spill-over occurs both ways. Finally, the rapid spread of invasive species via trade and travel is affecting both biodiversity and human health.

The agenda for a European Health Union (2020) was presented in the midst of a widespread resurgence of COVID-19. Of the people affected globally, 25% were living in Europe. The agenda describes long-term trends such as pressures on biodiversity, climate change and antimicrobial resistance as factors aggravating the spread of infectious diseases worldwide and in Europe. Underscoring the crucial role of improved preparedness against increasing outbreaks, it cites climate change mitigation and adaptation, biodiversity preservation and restoration, improved diets and lifestyles, and pollution reduction and removal from the environment as important elements. The amended proposal for a European Centre for Disease Prevention and Control recommends a One-Health approach that recognises the interconnections between human and animal health and the environment.

Mental, physical and cultural wellbeing

It is well established that biodiversity is central to many cultures and traditions, and that mental and physical health benefit from exposure to nature and bio-diversity. Given that 74% of the EU's population is urban (55% globally), there is a rising trend for people to be separated from nature and deprived of its health benefits.

Studies of populations in developed countries show that access to natural green spaces and biodiversity has significant health benefits, stemming notably from increased physical activity, exposure to microbial diversity as well as psychosocial factors. Benefits include lower incidence and risk of mental illness (such as depression, anxiety and stress), cardiovascular diseases and NCDs; improved immune function, and reduced overall mortality. Reduced recuperation times and improved recovery outcomes in hospital patients have also been reported. Exposure to nature is especially important for childhood development and health. Children who grow up close to nature are more likely to conserve nature themselves as adults, while those in developed countries increasingly suffer from "nature-deficit disorder" due to lack of outdoor activity.

In terms of cultural wellbeing, species, habitats, ecosystems and landscapes inspire forms of music, language, art, literature and dance. They are essential to food production systems, culinary traditions, traditional medicine, rituals, worldviews and social systems.

Green infrastructure (GI), as laid out in the EU Strategy on Green Infrastructure is key for providing increased exposure to nature, especially in nature-deprived urban environments. The European Parliament's pilot project on BiodiverCities aims to engage citizens in vision-building towards enhancing urban biodiversity, and to assess how urban GI can provide local and regional benefits. Further GI development is being informed by reports on the impact of nature-based solutions and the health and social benefits of nature and biodiversity in the EU. These indicate multiple benefits for physical, psychological and social wellbeing at the individual and community level: ranging from social cohesion to improved mental health and reduced cardiovascular and respiratory diseases.

Medicines

Modern pharmaceuticals as well as traditional medicine are heavily dependent on biodiversity. On the other hand, pharmaceutical release into the environment has become a major threat to both biodiversity and health.

Modern pharmaceuticals
Most diseases that afflicted or killed people a century ago are today curable or preventable thanks to modern medicines, many of which are derived from biodiversity and natural products: perhaps the most direct link between biodiversity and medicine. Antibiotics that greatly improved human health in the 20th century derive from microorganisms: the penicillins, as well as nine of thirteen other major classes of antibiotics. Nature-derived antimicrobials (antibacterials, antivirals, antiparasitics, antifungals) constituted more than 75% of those approved by the USFDA between 1981 and 2010. Despite substantial advances in synthetic drug design, biodiversity continues to be crucial for the development of new drugs and treatments, as well as new insights into human health. Most of the medicinal potential of nature has yet to be tapped: plants have been the single greatest source, but the majority have not yet been studied for medicinal potential. Microbial and marine organisms, studied only since recently, hold vast potential. Finally, of even greater importance than the medicinal potential of individual species, is the insight that biodiversity and ecology provide into how infections are attacked by natural means. Yet many of these crucial organisms, species and habitats are increasingly endangered with extinction by human action.

On the other hand, the release of pharmaceuticals into the environment presents dangers for biodiversity as well as human health. A range of active pharmaceutical ingredients or APIs (hormones, antimicrobials and anti-depressants) have been detected in rivers and streams across the world. Designed to interact with targets (receptor, enzyme or biological process) in humans and animals, they also affect organisms in the natural environment. APIs can be released via aquaculture and pasture animals and via manufacturing processes, sewage systems, surface water or soils. Limiting antimicrobial use would provide biodiversity and health co-benefits: excessive use alters the human microbiome and cultivates highly resistant bacterial strains in plants, animals and humans. Endocrine-disrupting chemicals and non-steroidal anti-inflammatory drugs have also had adverse effects on ecosystems, wildlife and human health.

Directive 2008/105/EC (amended by the 2013 Priority Substances Directive) on environmental quality standards in water policy obliges the European Commission to develop a strategic approach to water pollution from pharmaceutical substances, and to address the environmental impact. In November 2020, the new Commission Implementing Decision (EU) 2020/1729 on the monitoring of antimicrobial resistance in zoonotic and commensal bacteria was published, as part of the 2017 EU One Health Action Plan against Antimicrobial Resistance. The EU4Health regulation establishing the new EU4Health programme (2021-27) includes the specific objective of "supporting the prudent and efficient use of medicinal products, in particular antimicrobials, and actions to support the development of medicinal products that are less harmful for the environment, as well as the environmentally friendly production and disposal of medicinal products." The Farm to Fork Strategy aims to halve overall EU sales of antimicrobials for farmed animals and in aquaculture by 2030.

Traditional medicine
Millions of people rely on traditional medicine based on biological resources, well-functioning ecosystems and the context-specific knowledge of local health practitioners. Plants used in traditional medicine are crucial for local healthcare, but also for global innovations in healthcare and the associated international trade. They enter global commodity chains based on information gathered from their use in traditional medical pharmacopeia. Many of these plant and animal resources are on the verge of extinction, mainly due to overharvesting, habitat alteration and climate change. This also threatens livelihoods of practitioners and collectors, who are often poor. Traditional medical knowledge often inspires industrial R&D processes in bio-resource based sectors, necessitating mechanisms to secure attribution and sharing of rights and benefits with knowledge holders, as set out in the CBD's Nagoya Protocol on access to genetic resources and equitable sharing of benefits arising from their commercial utilization, to which the EU is a signatory.

The simplified registration procedure for traditional herbal medicinal products introduced by EU Directive 2004/24/EC clarifies uncertainties in the status of these products and facilitates their free movement through harmonised rules. It was intended for herbal medicinal products with a long tradition of medicinal use which do not fulfil "well established use" requirements for marketing authorisation, i.e. published scientific literature on recognised efficacy and safety. The Committee for Herbal Medicinal Products (HMPC), set up in 2004 at the European Medicines Agency (EMA), was tasked with establishing monographs for traditional herbal medicinal products. A new HMPC work plan was adopted in January 2022.