Colin Khoury: ‘We are all beneficiaries of ancient farmers in far-flung lands’

Last month, the UK-based biological research journal Proceedings of the Royal Society B published a paper, Origins of Food Crops Connect Countries Worldwide, that took a comprehensive look for the first time at how crops and countries are connected; what is native to a region and what travelled to where. Colin Khoury, its lead author, is with the International Center for Tropical Agriculture (CIAT) and United States Department of Agriculture. In an email interview, he elaborated on the journey of foods and how globalization has given a spurt to it.

How did the idea for doing such a study come about? What were your objectives?

There are two answers to this question:

a) The history of our relationships with domesticated plants and animals cannot be overstated in its importance to the evolution of human culture. When one pauses to think about it, it is apparent that these are the deepest relationships we have with other organisms on this planet.

It was striking to me as I grew up in my scientific career to begin to understand this history better. Raised in the United States, I think I was given a very superficial understanding of the history of food. In particular, I remember learning that ‘agriculture was born in the Fertile Crescent’ (the region from the Nile in Egypt up to Turkey and then down again into Iraq). While this is not untrue, it is only part of the truth! I suspect that Indian education is better in this regard.

It is also striking to me that it has really only been in the past hundred years or so that we have really started to learn with certainty about where our food originates. The Russian scientist N.I. Vavilov is considered the grandfather of my field (the conservation of agricultural genetic resources) because of his understanding, through extensive travels on all continents, that agriculture developed in many places, and that these places have particular attributes: they are very diverse environmentally and culturally, they have a great diversity of crops, and a great diversity of types (varieties) of those crops (e.g. different wheats in each valley in Central Asia), and also a great diversity of crop wild relatives, the wild cousins of our cultivated species.

While we have been building evidence (archeological, anthropological, linguistic, genetic, taxonomic, etc.) for a hundred years about where crops come from, no one had previously applied this information to what people around the world actually grow and/or eat now, in the present, to ask questions like “what regions of the world are the most important as the origins of modern diets?” and “what regions of the world are the origins of the foods eaten in X, Y, and Z countries?”. This is what makes our study unique- we compile the scientific studies on the origins, and apply them to present day food systems.

b) In 2002 a new International Treaty was written at the United Nations in Rome, which came into effect in 2004. It is the only new International Treaty that the world has agreed upon thus far in this millennium. The Plant Treaty in its essence is about interdependence among countries on crop genetic resources- that is, for modern agriculture, countries need each other’s crop diversity in order to keep their own agriculture productive and resilient.

One of the pieces of information that helped bring the Treaty into being was a small scientific study done 20 years ago that tried to estimate how much countries are dependent on other countries based on what they eat and where those foods originated (where the crops were initially domesticated and evolved over thousands of years). The argument is this: where a crop has been the longest is where the greatest genetic diversity is (it’s a matter of time). Because modern agriculture needs consistent access to genetic diversity in crops in order to breed new varieties that are adapted to new issues (pests and diseases, climate change, etc), the origins of crops are important. Thus if you eat potatoes, the Andean region of South America is important to you with regard to long-term food security, etc. The study was never published in a scientific journal and was quite a superficial study, but it inspired me to do basically the full version- look at every country and what they eat and also what they grow, and then link the origins of all crops to all countries, to see how connected we are with regard to the origins of crops. So I wrote to the author of that first study and she became a co-author and collaborator, and we moved forward to publish the fully comprehensive version, 20 years later!

Interestingly, this new study is having some effect in modern negotiations of the same Treaty. There is still work to be done to get countries to ratify (India is a member, but the US has not yet ratified although they signed the Treaty immediately back in the early 2000s. Apparently the ratification is soon finally going to go to the US Senate floor for discussion). Also the Treaty only covers some crops that we all know we are interdependent on (e.g. maize, potato, rice, wheat). But it misses some big crops (soybean, peanut and sugarcane), and also there are new crops that have become global (as you mention, quinoa, and because now something like 150 countries cultivate quinoa, it really should be covered under the Treaty). We hope that the study will have some real positive effect in getting more collaboration within the Treaty to take care of these globally important resources, make sure they are kept in the public domain for everyone’s benefit, and make sure they are accessible to everyone.

Your paper says that the last 50 years has seen an increase of non-native food crops. What is the reason for it and the most telling examples of this shift?

My experience in agriculture is that farmers have always shared and exchanged seeds. That is our norm. Thus it’s not so surprising to me that once transportation allowed, plants quickly got to new places. For instance, just 16 years after Europeans first saw potatoes, they were already being grown in Europe! That’s so fast, especially for a plant that is essentially poisonous, aside from its tubers.

So in some ways what was surprising to me about our results was that things are still changing. That is, in the past 50 years, diets and production around the world have changed quite a lot. On that note, you might be interested in a study we did a couple of years ago that is directly about that change. I think that the increase in production/consumption of ‘foreign’ crops is associated with some mega trends- economic development (and associated rise in middle class and thus greater purchasing power to buy exotic products), urbanization (all kinds of changes with people eating more in restaurants and fast food, buying in supermarkets, women working outside the home and thus cooking less, etc.), and globalization (trade laws enabling faster movement of goods, multinational food companies, much greater transport infrastructure (boats, refrigerated airplanes, etc), and the ongoing movement of people and their foods (thus the curry being one of the national foods of modern England!).

Whether this is all good or bad is complicated. In the past 50 years, despite growing population, we have reduced the number of undernourished in the world. Yet we now have more over-nourished (that is, that eat excessive macronutrients such as carbohydrates, protein, and fat) people than undernourished. Even in India this is becoming a real issue. On the production side there are also both positives I think (e.g. quinoa is a great plant) and challenges (greater dependence on wheat, rice, maize, soybean, palm oil worldwide, and therefore on the mega-production areas that produce them for the world, has its inherent risks).

Are there any main factors that make a culture adapt non-native foods?

I understand that there can be agricultural factors and also dietary factors that facilitate adoption. For instance, in the Mediterranean (e.g. Italy), traditional cereals are winter cereals (sown in the fall, harvested in spring/early summer). This meant, especially for the poorest people, that certain times of the year, especially on poor production years, left people vulnerable to food scarcity. When maize was introduced in the Columbian exchange, it was widely adopted because it grew in the summer and was harvested in the fall, filling an unfilled niche!

There are also very interesting stories for adoption of crops that are more cultural, or even random, in nature. For example, I understand that sunflower (which is from North America) became very popular as an oil in Eastern Europe in part because many other oils (and all animal fats) were prohibited during Lent (Christian period of fasting). Because the Orthodox Church did not prohibit sunflower, people used it more, and it gradually became more popular. It’s still extremely important in Eastern Europe and even in the Mediterranean (just behind olives in Turkey, Greece and Italy!). Mennonite immigrants from Eastern Europe then brought it to places like Argentina and Canada (back to its origins!), and their immigration is part of the reason why sunflower is important in those countries. Many crops have such interesting twisty stories, although many of these stories have unfortunately been lost over time.

Three major staples of Indian cooking—wheat, onions and tomatoes—are foreign in origin. Where do they originate from and what is the process by which we know it? And is there any hypothesis on when and how they came to India?

One thing to clarify- in the paper we purposely use a new term called “primary region of diversity” rather than ‘origin’. There are a number of reasons why we chose to use the term ‘primary region of diversity’ rather than centre of origin or other terms. One is that it is tremendously difficult to identify the specific exact place where a crop originated (especially in the tropics where archeological data does not preserve well). Scientists prefer the term ‘center of diversity’ as a more manageable and agreeable term, because it is more possible to identify where the diversity of old crop varieties and wild relatives are concentrated. In order to be inclusive and to align with country borders (to do the analysis), we use the term ‘regions of diversity’ because they are quite large and general- 23 regions around the world. Note that this also allows us to be conservative in our ‘native’ vs ‘foreign’ estimates (i.e. we are not overestimating how much foreign food people eat/produce).

The other thing is that we wanted to create an updated (modern) understanding of the geography of important plant diversity (crop genetic diversity) as this is the really important thing with regard to scientific and political implications of the research. We can argue that apples ‘originated’ in a cultivated form first in one region (Central Asia), but the reality of modern apples is that they have very important genetic diversity from wild relatives and early domesticated forms from East Asia and from Europe as well as Central Asia. Same for oil palm- the most cultivated modern oil palm is a mixture of West African and Neotropical genetic diversity, from two species of palm.

As crops have traveled all over the world, diversity has been generated in new places- e.g. diversity of barleys and oats (crops from the Old World) in North America are remarkably high. These are called “secondary regions of diversity” and other terms. What we did our best to do, and admittedly it was very challenging for some crops, was to create and define a manageable area for each crop as to its ‘primary region of diversity’- where a crop originated in general, but more importantly, where the great majority of genetic diversity in old farmer varieties and crop wild relatives are to be found. This is not to say that other regions (secondary, etc.) are not important for conservation and sharing of diversity, but the primary regions are arguably the most important.

So, for wheat, we actually assigned it to three primary regions of diversity due to great variation in old varieties and wild relatives: the South and East Mediterranean, West Asia, and Central Asia. Onions were assigned to Central Asia and West Asia. The primary region of diversity of tomatoes is Andean South America.

Wheat and onions probably made it to the Indian subcontinent a thousand or more years ago, given that there were great trade-routes by that time all the way from East Asia to the Mediterranean. Tomato arrived only during the Columbian exchange (i.e. post 1492). I do not know the history any more exactly than that, although I do know that the Portuguese had a role in moving plants from the Americas to their settlements in India.

On the note on onions and tomatoes- these are truly incredible foods, aren’t they, in their adaptability to cuisines around the world!? There are few national cuisines where these two plants are not incredibly important. I’ve been thinking about why this is but haven’t come up with anything clear yet, although it must have to do with their complementarity to other foods – a good balance of acid, flavor, etc.

The paper says that for South Asia, these foods were native in origin–areca nuts, coconut, lentil, bananas, cucumbers, mangoes, sesame, castor oils, dates, melons, sugar cane, chick peas, egg plants, millets, taro, figs, okra, tea, chicory roots, ginger, pepper, walnut, ginger, cinnamon, hemp seeds, pigeon peas, yam, clover, lemons and lime, rice. Can you give some idea about how you found out that these foods have their origin in south Asia?

Please note my words above about our terminology (primary regions of diversity of crops). As noted above, we compiled literature from archeological, anthropological, linguistic, genetic, taxonomic, etc. science and were purposely inclusive about assigning primary regions of diversity to crops (again so as to try not to overestimate how much ‘foreign’ crops a country produces or consumes). For a list of all crops and their regions, please see table 1 accessible here.

What are the other findings specific to India that you think is noteworthy?

After we assigned all the crops to one or more ‘primary regions of diversity’ around the world, we then looked at each countries’ diet and agricultural production, and summed up how much of the diet/production was of crops of which primary regions of diversity. We have this data for all countries, including India.

Following from that, what we actually did for each country and for each measurement (calories, fat, etc.) to estimate native vs foreign, was first assume the diet/production is 100% foreign. We then subtract the amount of diet that is clearly ‘native’ (i.e. the portion of the diet comprised of crops whose primary region of diversity includes the country). Thus for India, any crops whose primary regions of diversity included South Asia were subtracted. This results in our “maximum use of foreign crops” metric. We then further subtracted from this number the percent of the diet that is of crops that we could not specify what their primary regions of diversity were (e.g. in dietary data there are categories such as “Fruits other” that we can’t do much with because they are not specific enough), arriving at a “minimum use of foreign crops” metric, which basically assumes that all the non-specified crops are native. So what we actually end up with is a range for each country. We then did some fancy stats to derive a statistically valid average between the minimum and the maximum in order to arrive at one number which we report in the text of the paper.

Let’s give calories in India as an example so that it is clear:

The average calories (per capita per day) from plants in the Indian food supply (reported over years 2009-2011) is 2208 kcal/cap/day. We found that 1171.3 (53% of total) of these calories were clearly of crops of South Asian primary region of diversity, thus our ‘maximum use of foreign crops’ for India for calories was 47%. Given that 98.3 (4.5% of total) calories were of ‘not-specified’ plants, our ‘minimum use of foreign crops’ for India for calories was 42.5%. Thus we can say that we think that between 42.5-47% of India’s food supply is comprised of ‘foreign’ crops. The fancy stats that incorporates both this range of uncertainty plus variation over the 3 years assessed (2009-2011) gives us a final estimate of 44.8% +/- 1.1 use of foreign crops in India.

Here are the statistics for all ways we measured diet and production:

Food supply:

Calories: 42.5-46.9% foreign crops (average is 44.8% +/- 1.1) Protein: 48.5-55.2% foreign crops (average 51.8% +/- 1.6) Fat: 72.5-77.1% foreign crops (74.7% +/- 1.0) Food weight: 38.2-60.0% foreign crops (50.0% +/- 5.3)

Agricultural production:

Production quantity: 32.7-37.6% foreign crops (35.3% +/- 1.4) Harvested area: 52.6-56.1% foreign crops (54.4 %+/- 1.3) Production value: 43.0-51.4% foreign crops (47.4% +/- 2.0)

Your paper says geographically isolated regions use foreign crops in greater measure. Why? And what is the level of foreign crop use in India? And are there any reasons for being at this particular level?

Biodiversity has general global patterns: more diverse typically in tropical and subtropical regions than in temperate ones (due to ice ages and other factors), and also more diverse in topographically and climatically varied places (because species have to adapt to these variations and thus become a variety of new species over time). Crop diversity follows these patterns and also is connected to where people have been for a long time- Abyssinica, West Asia, South Asia, etc.

Thus the more temperate regions of the world and especially islands (Australia, New Zealand, Madagascar, etc) have less crop diversity than other places (note all places have some level of crop or crop wild relative diversity (e.g. macadamia nut in Australia), but there are clearly some places where the conditions were right and where people became settled a long time ago where crop diversity is most diverse historically.

Statistics for India are given above. Because India is located in a region of great native crop diversity and still produces/eats many traditional foods, its statistics on level of foreign consumption/production are lower than the global average. One exception is for fat in the diet, and this is because India consumes a considerable amount of palm oil, groundnut, and soybean, all of which are of foreign primary regions of diversity.

Right now, quinoa seeds and chia seeds are being cultivated in India despite them being totally foreign to farmers just a couple of years ago. What would decide if quinoa and chia become popular and find home in India?

Innovations can be either on the supply side (e.g. technologies make cultivating certain plants more profitable than others) or on the demand side (consumers creating new markets through demand). It is interesting that the rise of both these crops in recent years has largely been driven by demand, particularly from health conscious relatively wealthy consumers. I don’t know if this is the group driving increase in India, but I would not be at all surprised if so.

Again I don’t know much about India, but given that the country has such a tremendously rich traditional food culture, I would not be surprised if there was also resistance to foreign foods to some degree. Interestingly in many places now like the US, UK, etc., celebrity chefs, Oprah Winfrey, etc. can increase (or decrease) consumption of new foods just by mentioning them (like kale).

Note that for a long time it was hard to grow quinoa outside its pretty unique region of diversity (high altitude dry cold mountainous environment). It took researchers finding some unique varieties that were more adaptable to other regions for quinoa to flourish in the USA and then in Europe and beyond.

What are the implications of your study?

Thanks for this question! As with many scientific papers, we report the results and only allude to the implications, so I appreciate the chance to expand on them a bit.

Agriculture (i.e. how we grow food) is not a static thing. Everything is changing. The environment changes, climate changes, demand changes (e.g. the rise in demand for quinoa worldwide). Crops and their varieties, therefore, are also always changing and evolving due to production challenges or to demand changes. Plant breeders are continually breeding new varieties to keep up with these changes, and to do so, they require genetic diversity. If there is one single place of most importance with regard to finding genetic diversity needed for any particular crop, it would be its “primary region of diversity”.

What this new study does is connect the crops important to the diet and/or the national agricultural production in countries to where these crops originally historically came from. We call these origins “primary regions of diversity” for a reason- they are historically especially diverse with regard to farmer varieties and to the wild and weedy cousin species (called “crop wild relatives”) of our crops. These crop wild relatives are the wild base from which ancient farmers started to domesticate crops. The diversity of farmer varieties exist because people have farmed the crops for many thousands of years in these places (e.g. potato in the Andean mountains of South America). Farming over long periods of time creates diversity in crop varieties.

The main result of the paper is that connecting countries’ food systems to the primary regions of diversity of the crops consumed and/or produced greats a giant interconnected web. We rely on each other’s plants. And therefore, for long term-food and nutrition security, we should be invested in the conservation and access to the genetic diversity of those plants, wherever they be, and especially where that diversity is most rich. One could argue that this may be especially true for the biggest producers of crops or for countries whose GDP is highly related to agriculture [e.g. for USA or Brazil’s connections to East Asia as the primary region of diversity of soybean (as USA and Brazil are the world’s biggest producers); but China as the world’s biggest producer of peanut should likewise be interested in conservation in Brazil (where peanut comes from)]. And so on until we understand that we all really need each other. Some perhaps more than others but all need each other because there is no country that uses only ‘native’ crop plants. And the study shows that this trend is becoming even more so over time (countries eat or produce more ‘foreign’ crops over the past 50 years).

The reality of how this works has its scientific and political aspects. We have seedbanks [for example where I work in Colorado, at the USA national seedbank, and where I work in Colombia, at the international seedbank with global responsibilities for beans, cassava, and some other important food security crops (CIAT)] that are the main repositories now for such genetic diversity. Many of these seedbanks are sorely underfunded, though, and thus cannot meet the expectations placed on them to conserve and distribute this diversity. Note though that some diversity exists only in farmers’ fields or in the case of crop wild relatives, in the wild, and this diversity is generally highly threatened. You might be interested in another piece of work we did recently that looks at how well conserved crop wild relatives are globally. The result, unfortunately, is that they are not very well conserved. This means that more conservation work is particularly needed in the primary regions of diversity of food crops to protect these special genetic resources before they disappear.

On the political side- we have the International Treaty which really is a remarkable achievement in recognizing our global interdependence regarding crop diversity, but we have a long way to go before we as a global community act fully in the intention of the Treaty (i.e. easily work together to conserve and share this diversity).

One other point: there are economic and political forces that are blocking farmers from practicing their traditions of conservation and exchange of crop varieties. I would argue that the results should also lead us to understand how we are all the beneficiaries of ancient (and more recent) farmers in far-flung lands, and that we should respect farmer’s rights to their traditional practices which generated in the first place this diversity we all benefit from. The political term for this is called “Farmer’s Rights” and it’s also part of the Plant Treaty, although it’s not yet well worked out how to really implement it for the benefit of farmers in primary regions of diversity and elsewhere.

To sum up: the results, in understanding just how global our food system is, mean we need an increase in acting globally to appreciate, conserve and make accessible the diversity in our food crops for everyone’s benefit. If we can increase our consciousness with regard to the geography of crop diversity and act on it, then these efforts will increase long-term food and nutrition security.

My specific recommendations would be that countries:

1. Collaborate internationally to conserve crop diversity in all its forms (including wild relatives) in their natural habitats (as possible) and also in seedbanks, botanical gardens, etc. where that diversity can be safeguarded.

2. Collaborate internationally to ensure that all people have access to this diversity. This means investment in the Plant Treaty and other international measures to work together to share diversity, and investment in the international seedbanks that conserve and share this diversity for the planet. It also means making sure that these resources are not privatized/patented. As everyone needs and benefits from them, and because they are living beings that (at least for domesticated varieties) are the result of many generations efforts of farming communities and cultures, they should be considered “global public goods” and therefore not privatizable in their native/original form for the profit of any corporation or organization.

3. Collaborate internationally to use this diversity to make our important crops more resilient and more sustainable. Note that as more of the world relies on wheat, or soybean, or palm oil, ever more important is that their production is stable and sustainable. Big issues like methane emissions from processing of oil palm, or forest loss due to more soybean production in tropical regions, affect us all indirectly. The use of genetic diversity is one of the most promising long-term solutions to many of these issues (by breeding crops to be more resilient and use less resources to be productive).

4. Collaborate internationally to ensure that Farmer’s Rights to practice their traditional methods of cultivation, conservation and exchange, which created this diversity in the first place, are respected. This needs to happen through the Plant Treaty and through other legal instruments.

(Also Read: Foreign Superfoods: The Global Gut)

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