One Earth, One Health

“Between animal and human medicine there are no dividing lines—nor should there be.
The object is different but the experience obtained constitutes the basis of all medicine
.” ~ Rudolf Virchow, MD

The world is getting smaller.

Or so technology and communication make it seem.

worldhealth_symbols_TechHuman population is increasing and we’re continually expanding across the globe.

As our technology advances, so does our understanding of our interdependency on the environment, each other and the animals we share our planet with.

That’s why over 850 doctors, veterinarians and scientists from across multiple disciplines endorse and participate in the One Health initiative–the subject of today’s blog post.

This will be the first in a series, which explores the concept of One Health and the connections between humans, animals and the environment–and why it is so important to each and every one of us.

What Is One Health All About?

The simple answer is this: One Health is an idea that recognizes that human and animal health are directly related to each other — and the environment.

But One Health is more than an abstract concept. It’s a worldwide integrative effort which encourages collaboration between physicians, veterinarians, nurses, biomedical scientists and environmentally related disciplines to promote, improve and defend the best possible health for all species.world_graphic_2-01


The One Health goals will be realized through joint educational projects among schools of human and veterinary medicine, schools of public health, colleges of agricultural and environmental sciences, as well as education of the general public.

How a 19th Century Idea Made Its Way Into the 21st

One Health is the ‘modern’ form of a concept which is now hundreds of years old.

The multi-disciplinary idea originated with a single physician (Rudolf Virchow) who lived in the 18th century. While he was studying a specific type of roundworm in pigs, he noticed the link between human and veterinary medicine and even coined the word ‘zoonosis’ to describe infectious diseases that passed between animals and humans.

Here’s the history which has led to One Health in a nutshell:

1821-1902 — Dr. Virchow recognized the link between humans and animals, worldhealth_symbols_Population Healthadvocating for improved veterinary education.

1849-1919 — Canadian physician William Osler also became interested in the link between the study of animal and human health. Author of The Relation of Animals to Man, Dr. Osler would later become the first Physician-in-Chief at Johns Hopkins Hospital and played a crucial role in establishing their School of Medicine. He is now known as the father of veterinary pathology in North America.

1947 — The Centers for Disease Control and Prevention (CDC) established the Veterinary Public Health Division, acknowledging that good human health is related to good animal health.

1964 — Dr. Calvin Schwabe coined the phrase ‘One Medicine’ in his textbook Veterinary Medicine and Human Health to describe the similarities between human and veterinary medicine, encouraging collaboration among disciplines for the prevention, control and treatment of diseases that affect both humans and animals. Two years later, Dr. Schwabe became the founding chair of the Department of Epidemiology and Preventive Medicine at the School of Veterinary Medicine at the University of California Davis — the first of its kind at a veterinary school.

2007 — Working with the American Veterinary Medical Association,
the American Medical Association worldhealth_symbols_Public Healthpassed the One Health Resolution to promote collaboration between the two disciplines.

2009 —‘One Medicine’ was changed to ‘One Health’ and the key recommendations for ‘One World, One Health™’ were developed.

It is important to note here that thanks to Dr. Schwabe and all who followed him, the University of California Davis School of Veterinary Medicine (the top veterinary school in the world!) has played a pivotal role in One Health. From the very beginning, UC Davis has been at the forefront of the initiative with its One Health Institute, a global effort “working at the interface of animals, people and the environment to solve complex problems that impact health and conservation.”

But UC Davis is far from alone. The World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO), World Organization for Animal Health (OIE), United Nations Children’s Fund (UNICEF), United Nations System Influenza Coordination (UNSIC), World Bank and representatives from more than 120 countries and 26 international and regional organizations have participated actively in the One Health discussion since 2007.

How Does One Health Work in Practice?

The Importance of Zoonotic Infections

One of the most important aspects of One Health is its focus on zoonotic infections–diseases that can be passed between animals and humans — including those caused by parasites, bacteria, viruses and fungi. Health professionals estimate that 70% of emerging and reemerging infections worldwide are vector-borne or zoonotic.

The zoonotic diseases area focuses on:worldhealth_symbols_Environmental

  • Vaccines and therapeutics
  • Antimicrobial resistance
  • Surveillance, sanitation and vector control (such as in the current Zika virus outbreak)
  • Global health
  • Food safety (e.g. food contamination by pathogens)
  • Bio threats

Probably one of the best instances of how One Health (and the study of zoonotic infections) has changed the world is the smallpox vaccine.

In 1796, British physician and scientist Edward Jenner noticed that milkmaids who had come down with cowpox later seemed to be immune to smallpox.

worldhealth_symbols_Human MedicineSome 20 years earlier, a farmer named Benjamin Jetsy had successfully inoculated his wife and sons with cowpox to protect them from the deadlier smallpox infection.

In 1776, Jenner picked up where Jetsy left off and began experimenting, finally developing the very first successful vaccine in the world.

In fact, the word ‘vaccine’ is derived from the term Jenner used for cowpox — i.e. Variolae vaccinae or ‘small pox of the cow’ (from Latin vaccinus (adjective) “of or from cows,” from vacca “cow”).  The term vaccine was initially only used to refer to smallpox. In 1881, Louis Pasteur proposed to extend the term to include all new protective innoculations.

What We Can Learn From Cows (and All Other Animals)

Aside from the important work in zoonotic infections, worldhealth_symbols_Social Sciencethe One Health initiative also focuses on Comparative and Translational Medicine. Comparative Medicine is the concept of studying diseases in both humans and animals in order to discover similarities and/or common solutions while ‘translational’ medicine (sometimes called ‘bench to bedside’ medicine) is the clinical application of diagnostic tools or treatments tested in the lab (or in a species other than humans).

Examples of comparative and translational medicine include the study of:

  • Cancer and cardiovascular disease in humans and animals
  • Metabolic disorders in humans and animals
  • Joint and skeletal diseases in humans and animals
  • Environmental hazards exposure to humans and animals
  • The human-animal bond

worldhealth_symbols_Veterinary MedicineA great real life example is the work done at the Comparative Oncology Program of the UC Davis Comprehensive Cancer Center where, in an effort to improve human cancer treatment, veterinarians perform clinical trials on ‘pet’ dogs and then share their findings with doctors treating cancer in humans.

Pet dogs are used because they make superior study subjects than mice; they are exposed to the same environments as humans and fall prey to similar kinds of cancers as humans do. This very important collaboration between human and veterinary medicine could very well save many human and canine lives from devastating cancers.

A win-win, the important work at UC Davis is a prime example of One Health in action.

The Food Connection–Why Diet Should Be Included

To date, diet–and specifically a plant-based diet–has not been included in the concept of One Health. To my mind, this is an important omission that needs to be addressed particularly given the deep connections that tie agriculture (especially plant foods), animals and humans together.

Beriberi–A Classic Example

A great demonstration of ‘diet and One Health’ in action is Dr. Eijkman’s beriberi study at the beginning of the
20th century.

Christian Eijkman, a Dutch physician, went to Indonesia to study beriberi, a Mar 01_OneHealth_Illustrate1_57907520disease of the peripheral nerves. While there, he noticed that some of the chickens used in his lab were showing symptoms of beriberi after having been fed leftover ‘polished’ rice from military rations. Once the bird’s diet switched back to unpolished rice, the birds recovered in a matter of days.

Eijkman reasoned correctly that the polished rice must lack a nutrient that would normally protect the chickens from an onslaught of beriberi. He ultimately discovered the missing compound to be vitamin B1, thiamine. (As we mentioned in our vitamin article, the chemist Kasimierz Funk coined the term ‘vitamine’, later shortened to vitamin, from the discovery of thiamine.)

For his contribution to the subject of nutrition, Eijkman won the 1929 Nobel Prize for Physiology or Medicine alongside Sir Frederick Hopkins while Funk was sadly never given credit for his contribution.

The China Study

A second illustration of the intersection of diet and health in both humans and animals is the groundbreaking work by Dr. T. Colin Campbell who conducted studies in the Philippines, China and the US.

Growing up on a farm, Dr. Campbell wanted to be a veterinarian and began his career by studying animal nutrition. His work in the Philippines was to coordinate a nationwide effort to insure adequate protein consumption in malnourished children. Later, he started a series of studies on the relationship between protein-rich diets and cancer. What he discovered shocked him; he began to see firsthand the debilitating impact of animal-based diets on human health.

The research he conducted in China was memorialized in his bestselling book The China Study, which briefly describes the China-Cornell-Oxford Project, a 20-year study described by The New York Times as “the Grand Prix of epidemiology”. The China Study discusses the link between the consumption of animal foods and chronic illness such as cardiovascular disease, diabetes, and breast, prostate and bowel cancers.

Angiogenesis and the Diet Factor

The third and final example of the importance of diet to disease is the work on angiogenesis.

A natural process essential for healing and growth, angiogenesis is the growth of new capillary blood vessels in
the body. However too much (or too little) blood vessel growth appears to be a contributing factor to an array of chronic illnesses including cancer.

worldhealth_symbols_Nutrition - DieteticsIf you recall, in our article about berries, we showed how eating phytonutrient rich berries can actually starve tumors of their blood supply by blocking the cancer’s ability to create the new blood vessels they need to grow.

We also mentioned Dr. William Li’s famous “Can We Eat To Starve Cancer” TED talk. In that presentation, Li emphasizes the fact that diet is a big environmental contributor (30-35%) when it comes to the onset and progression of cancer and stresses the importance of eating foods that have natural antiangiogenic properties.

He then lists the foods (all plant-based) which have been shown to inhibit angiogenesis: green tea, strawberries, blackberries, raspberries, blueberries, oranges, grapefruit, lemons, apples, pineapple, cherries, red grapes, bok choy, kale, soybeans, ginseng, Maitake mushroom, licorice, turmeric, nutmeg, artichokes, lavender, pumpkin, sea cucumber, parsley, garlic, tomato, and dark chocolate.

Bringing Plant-Based Eating in out of the RainFresh strawberry isolated on white background

Decades of research have shown that a shift from the Standard American Diet (SAD) diet to a predominantly whole food, plant-based diet can prevent, or even reverse, many of the chronic and degenerative diseases afflicting our society.

Supporting that argument is the fact that cardiovascular disease, breast cancer, colon cancer, diabetes and hypertension are virtually unknown in countries where people eat an unprocessed, mostly plant-based diet. When they immigrate to the west and adopt the SAD diet, they start to suffer from the same chronic diseases as their American counterparts.

A conversation about the importance of a whole food, plant-based diet fits under One Health’s concept like no other. And in my next article, I’m going to tell you exactly how and why.