Three Foods That Might Not Survive Modern Diseases

What do olive oil, bananas, and honey have in common? They’re not ingredients in the latest celebrity-endorsed juice cleanse elixir. More ominously, they’re foods with uncertain fates. Olive groves in Italy are scenes of devastation as a bacterial pathogen spreads, leaving behind withered, brown trees in its wake. A fungus is infiltrating soils in the tropics, and it has the potential to make half the bananas on earth go extinct. A trifecta of maladies are bringing down honeybees, a plight that threatens not just honey, but a third of the food produced on the planet.

It’s that worldwide reach that also hastes the pandemic-like spread of pathogens that infect food.

In the U.S., the expansive global market often insulates consumers from noticing the effects of these food pandemics: If your favorite Tuscan olive oil disappears from shelves, a fine Andalucian version from Spain is probably the next shelf over. But it’s that worldwide reach that also hastens the pandemic-like spread of these food maladies. If left unchecked, certain aisles might one day be empty. Here, experts weigh in on the prognoses for three different foods that could potentially be doomed by diseases.

Bacteria in the boot

Johnny Madge clears his throat before describing what it was like to drive into Puglia, the region of Italy that encompasses the heel of the boot-like peninsula. Visitors would normally describe the villas, the thousand-year-old farms, whitewashed houses, and the salty, crystalline waters of the Mediterranean. Madge however, an olive oil expert based in Lazio, Italy, lowers his voice like he’s telling a ghost story. "You got the feeling you were approaching something like Chernobyl," he says.

That description refers to the olive groves in Puglia; the withered, barren trees that make it seem like a wildfire has ravaged the once verdant hills. This post-apocalyptic landscape is the result of a plant disease caused by the bacterium Xylella fastidiosa pauca, a deadly pathogen that threatens to usurp the ancient farms.

Infected olive tress in Puglia. Photo: Tiziana Fabi/AFP/Getty Images

Since the outbreak started, the infectious zone has spread north, moving dangerously close to the ankle of the Italian boot. Puglia’s geographical location at the heart of the Mediterranean’s olive growing regions — and the Italian authorities’ inability to enforce containment measures — has the European Union worried about imminent spread. If X. fastidiosa — which is transmitted from tree to tree by insects — spills out of the boot, the trees that produce 95 percent of the world’s olive oil would likely be in jeopardy.

In Italy, the olive trees are more than just a crop. "When you talk to people about olive oil in the Mediterranean, blood is almost the right word," says Madge. "They’ve had these trees in their families for over thousands of years. They think of them almost as grandparents." In Puglia, Madge described farmers crying, mourning the loss of trees they had picnicked under since they were children. These trees had produced oil that preserved food before refrigerators, and fueled lamps before electricity; they yielded harvests that farmers took for granted until X. fastidiosa.

"In the Mediterranean, they’ve had these trees in their families for thousands of years."

In the United States, spunky Puglia olive oil varietals like Cellina di Nardò — which is particularly vulnerable to X. fastidiosa — have a more subtle presence, culturally and on store shelves. They’re chefs' secret weapons, used to add a finishing touch to a dish. The early harvest olives in Puglia produce oils that are "grassy, bitter, peppery, assertive, and robust," says Nicholas Coleman, olive oil expert and co-founder of Grove and Vine, a company that creates proprietary custom blends. "It’s like an invisible ingredient; most people don’t know that it’s been added at the end when they go to a nice restaurant," he says. These oils can retail for upwards of $50 when imported, a far cry from the ambiguously labeled "Extra Virgin" oils in the supermarket.

Good news: X. fastidiosa would have to spread through more than just a handful of Puglia varietals before Americans would notice. "The beauty of being in a generally non-producing country is that we’re not dependent on a local oil source, so we can be open to the world of olive oil," Coleman says.

Ironically, that same global network that help insulates American consumers from X. fastidiosa is likely behind its spread. According to Madge, X. fastidiosa is thought to have been transported to Europe as a stowaway in coffee shipped from South America. From there, the insect hitched a ride in trucks that hastened its northward advance.

The rest of the Mediterranean is watching with a wary eye. Scientists are testing different olive cultivars for natural resistance, and the efficacy of grafting resistant trees with those already infected. Recent court rulings in Europe have mandated containment measures, and Spain, the largest producer of olive oil in the world, is experimenting with resistant cultivars. For now, however, it’s a waiting game to see if measures will slow the spread of the disease.

A fungus underfoot

Every year, the world consumes a staggering number of bananas, and nearly half of those are of the Cavendish cultivar, virtually the only bananas produced for export since they became widespread in the 1950s. And every one of those Cavendish bananas are clones: the banana baby food you ate in your high chair is genetically identical to the one hastily eaten during your morning commute today, each grown from a clipping of a plant cultivated nearly 200 years ago.

As far as bananas go, the Cavendish is a workhorse. "It’s very productive," says Dr. Randy Ploetz, a professor of plant pathology at the University of Florida’s Institute of Food and Agricultural Sciences. "Of all the natural bananas out there, it produces the most fruit in the shortest amount of time, with the smallest amount of land."

It’s not just these qualities that propelled the Cavendish to number one status, however. In fact, the Cavendish was once considered to be a "junk banana" of inferior taste, according to Dan Koeppel, author of the book Banana: The Fate of the Fruit that Changed the World.

In the 1950s, growers had no choice but to turn to the bland Cavendish when Gros Michel, the once-preferred cultivar, was wiped out across the globe by Panama disease, caused by a particularly nefarious strain of the fungus Fusarium called Tropical Race 1, or TR1. The fungus can lay dormant in the soil for decades, spreading from field to field on the boots of travelers, resistant to most treatments except those that were so environmentally detrimental that they were outlawed. Though less banana-y than their sister strain, the Cavendish’s claim to fame was its resistance to TR1.

"The real question is whether we’re going to have something useful by the time this spreads to the Americas."

Fusarium wasn’t to be outsmarted forever. These days there’s a new fungus in town, TR4, and it’s attacking Cavendish. This new strain of Panama disease evaded detection because of its long dormancy period — it slowly spreads from field to field before crops ever show symptoms. "People have underestimated the pernicious nature of this pathogen," Ploetz says, "but the horse is out of the barn now." For years, TR4 was seen only in Southeast Asia, but in 2013 it gained a foothold in Australia, then spread to the Middle East and Africa, leading to hundreds of millions of dollars in losses.

Now, it’s looming ever closer to Central and South America, the world’s largest producers and exporters of bananas. "If it jumps across the Atlantic, production would see the same kinds of impacts [as TR1 on Gros Michel]," Ploetz says. "It’s a scary thought." What the Cavendish have in common with Gros Michel is that they’re all genetically identical clones — if TR4 wipes out Cavendish in the Philippines, it will be equally deadly to every plant around the world.

It’s no longer a question of if TR4 will come to America, but when. "It’s probably inevitable, given the way people travel internationally," warns Ploetz. "The real question is whether we’re going to have something useful in hand by the time this spreads to the Americas." Until TR4 reaches South America, banana lovers in the US might not notice any effects. After TR4 spreads, however, the only hope is to have a resistant cultivar ready to step in for Cavendish.

Developing a new cultivar that could live up to the Cavendish standard is a tall order. Wild bananas grow more slowly and have large seeds, which makes them unsuitable for crossing with Cavendish to yield resistant crops. And funding for banana research programs in the US is scarce, as most money supports American staples like corn, wheat, or soybeans.

Ploetz argues that one viable strategy is to employ genetic modifications that would yield a pathogen-resistant hybrid with the qualities that made the Cavendish a powerhouse banana. Regardless of how it’s done, cultivating crops that can stand up to Panama disease is the only hope for saving this popular fruit. "How soon can we get resistant bananas out there?" Ploetz asks. "There are no other ways to manage this problem."

Honeybees on almond flowers. Photo: Radek Mica/AFP/Getty Images

A sticky situation

The worker bees of the United States go on a cross-country road trip once a year. Every February, commercial beekeepers pack their hives onto trucks and make a pilgrimage to the budding almond orchards in California. For three weeks, the bees fan out over the fields, pollinating the almond flowers. From California, the bees are carted up to Washington where they’ll pollinate apples and cherries, ultimately bumbling their way from crop to crop across the country, rounding out the season buzzing about the blueberry fields in Maine. When all’s said and done, pollinators are a critical step in getting one in every three bites of food to your fork. The problem? Beekeepers are struggling to keep their hives alive.

"Every year the annual losses are between 20 and 30 percent [of bees]," says Dr. Steven Cook, an entomologist at the United States Department of Agriculture’s Bee Research Center. "That’s too high for a commercial beekeepers to remain viable."

The decline in honey bees is caused by a dizzying ménage à trois of maladies. Pesticides leave bees with weakened immune systems, which make them more susceptible to a bloodsucking mite called, terrifyingly, Varroa destructor. If weakened immune systems and vampyric pests weren’t enough, the mites harbor viruses that cripple pupae, resulting in flightless adults that don’t survive. Though these deadly pesticides have been banned in Europe, US policy has lagged behind, and global travel has enabled the spread of Varroa around the globe. "The only place that doesn’t have Varroa mites?" Cook asks. "I think the Hawaiian island Kauai is still Varroa mite free… but it’s just one little island. Almost everywhere else in the world there are [mites] now."

"You might have many fewer options in terms of what fruit you can purchase."

If bee losses continue to go unchecked, consumers may start to feel the effects. And it won’t just be increased honey prices or bear-shaped bottled filled with tinted corn syrup in place of the real deal. "You might have many fewer options in terms of what fruit you can purchase," Cook says. Some estimates suggest that if current trends continue, there is no way food production will be able to exceed demand by 2050.

Almonds are particularly at risk, as their crops depend almost entirely on bees for pollination. By some calculations, commercial bees boost almond yields up to 60 times what they would be without buzzing, striped helpers. More than withering olive trees and threatened bananas, the effects of a dearth of bees can be felt by consumers now. Their decline is to thank for the comically high price of almond butter on supermarket shelves.

But researchers like Cook are hopeful. "I feel optimistic," he says. "We’ve come to the conclusion that there’s an interaction among stressors that are affecting colony health." The challenge is to convince the US to enact similar bee-saving policy changes as those in Europe. After all, the collapse of bees would seriously hamper almost a third of food production globally. The exception being plants that don’t rely on pollinators, like bananas. But then again, those might not be around, either.

Kyle Frischkorn is a freelance writer and graduate student studying oceanography at Columbia University.
Editor: Erin DeJesus