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Sickly Sweet: The Sugar Cane Industry and Kidney Disease

Symptoms of Chronic Kidney Disease of Unknown Origin, or CKDu, have been growing among sugar cane workers in nations under pressure to produce more sugar as countries like the United States increase their demand.

Americans have a notorious sweet tooth. The average American now consumes 20 teaspoons of combined sugars — just under half a cup and twice the recommended amount — every day. Our enormous consumption of sugar has been unequivocally linked to the high prevalence of obesity in American adults — over one third of the American adult population is obese — and has enlarged the diabetic population to the third largest in the world. But the effects of Americans’ sweet tooth reach farther than endangering personal health, embarrassing national statistics, and creating a lucrative oral-care industry: Their reach extends into the very sugar cane fields where yellow and white Domino’s bags originate.

For years now our sweet tooth has been slowly killing us, but we are the publicized victims of sugar’s health epidemics. Behind the scenes, thousands of low-wage sugar mill workers in sugar-cane producing countries are facing an ignored epidemic of their own: chronic kidney disease of unknown origin (CKDu).

CKDu, like chronic kidney failure (CKD), is “a degenerative, progressive condition marked by the gradual loss of kidney function.” But, unlike CKD, which mainly affects older men and women in developed countries and is caused by obesity, high blood pressure, and diabetes, CKDu “is associated with heavy labor in hot
temperatures, particularly among industrial agricultural workers such as those working in sugarcane

The disease is, largely, a silent killer. The early signs, jaundice and fatigue, go unnoticed. And, once advanced into its later stages CKDu’s treatments, dialysis or kidney transplants, are far too costly for sugar cane laborers in Central America. Yet, the prevalence of CKDu is highest in these very sugar-milling communities.

While CKD affects 16 percent of American adults, only 5 percent of cases in the United States are attributed to its cousin, CKDu. Meanwhile, in El Salvador, CKDu has become the leading cause of death amongst men, and since 2004, 46 percent of male deaths in Chichigalpa, Nicaraguathe country with the highest CKDu death rate in Latin America  — were caused by CKDu. In an area of Chichigalpa now called “La Isla de Viudas,” (the Island of Widows) 7 in 10 men have CKDu. A 2012 study found that CKDu has been linked to at least 20,000 deaths in Central America.

CKDu was first observed in 1994 in Sri Lankan rice paddy farming communities. Since then the disease has proliferated and affected 11 other countries on three continents, amongst them Central American sugar producing countries like El Salvador, Nicaragua, Guatemala and Honduras. Together, these four countries export over two million metric tons of sugar per year, and all four rank in the top 35 global sugar exporters.

Although CKDu was first acknowledged as a problem in Central America in 2000, it has existed in the region since the 1970s. According to Will Storr, reporting on the CKDu epidemic from El Savlador for the Guardian, the disease remained relatively unnoticed until recently because “there are no kidney specialists [in the deep countryside] to identify such an unusual condition. Out there, the poor simply die.” But today, CKDu is making its way out of the shadows where silent killers lurk and slowly into the eyes of the international community. In 2012, El Salvador’s minister of health, Maria Isabel Roderiguez, warned the international community that CKDu “is wasting away our populations.”

While CKD and CKDu differ in regard to the nature of their origin, the causes of the two diseases appear fundamentally intertwined: CKD is caused by excessive sugar consumption, while CKDu seems to be associated with the boom in sugar milling spurred by increased consumption and demand. The New York Times reported that in the past decade the Nicaraguan sugar industry quadrupled in size to a $500 million a year industry; the Central American sugar cane industry alone supplies North America with 23 percent of its raw sugar imports. Our excessive sugar consumption created a rapidly growing and lucrative, but largely unmonitored, sugar cane industry in developing countries that employs poor agricultural practices. Poor practices in sugar milling countries like El Salvador and Nicaragua expose harvesters to toxic pesticides and harrowing working conditions that appear to be associated with CKDu.

There are three camps of research that each posit their own solution to the pesky “u” in CKDu. While they don’t all agree on the cause of the disease, they do acknowledge that a high prevalence of CKDu exists in the sugar cane industry.

Daniel Brooks, a researcher and professor at Boston University, has conducted research finding that extreme heat and dehydration, not exposure to pesticides, is most likely to cause CKDu. Brooks uses evidence that shows that laborers exposed to similar pesticides in cooler environments have lower rates of CKDu than those exposed to the same pesticides in hotter settings. However, in a 2012 study Brooks affirmed that the cause of CKDu remains unknown.

Storr believes that researchers like Brooks are of the mind that  “the labourers are, in effect, working themselves to death.” A second theory, similar to Brooks’, developed by Richard J. Johnson, a researcher at the University of Colorado, found that the ingestion of large amounts of sugar causes tubular damage of the kidneys similar to that found in CKDu patients. Johnson has theorized that dehydrated workers hydrate themselves with sweet drinks like juices or soft drinks and overload themselves with a “toxic” amount of sugar.  Both Brooks’ and Johnson’s theories minimize the links between the sugar cane industry and CKDu and have therefore been embraced by the industry.

On the other hand researchers interviewed by Storr, like Dr. Carlos Orantes — a kidney specialist with El Salvador’s ministry of health who has studied CKDu since 2009 — believe that pesticides have a strong role in the development of CKDu in agricultural workers. Orantes names three factors in the development of CKDu: “[the use of] prohibited pesticides, combinations of pesticides, and no protection from pesticides.”

For his piece, Storr sent Professor Andrew Watterson, an expert on agrochemicals and health at the University of Stirling, the recipe for the liquids he saw sprayed in the sugar cane fields of El Salvador. Watterson concluded that while none of the chemicals being used — herbicides such as atrazine, 2.4-D, terbutryn and pendimethalin — are individually “acutely toxic…‘this combination, plus the tropical climate, could worsen their effects.’” Furthermore, long-term exposure in lab rats to all of the aforementioned herbicides has been found to be harmful to the kidneys. The third field of research, like Orantes, believes that poor working conditions, inadequate protection from chemicals during handling, and aggravating environmental factors result in kidney damage like that seen in CKDu.

While the three camps have yet to come to a definitive conclusion either independently or collectively, all three theories relate back to the sugar cane industry in some respect — an impression the industry is eager to dispel.

In hopes of distancing itself from the CKDu epidemic, the sugar industry has embraced Brooks’ theory that workers contract CKDu by working themselves too hard. Yet even if the sugar industry claims that dehydration and oppressively hot climates are no fault of their own, their employment practices aggravate the circumstances.

In El Salvador, Storr observed many workers taking on double shifts during the summer in 104-degree temperatures with no potable water in sight. He also observed workers mixing and spraying herbicides with no protection, and was told by a jefe at one of the fields that it is up to the individual to provide their own protection gear. Boots alone are $10 — practically unaffordable on the $5 a day the workers received at the field Storr visited. Regardless of whether or not herbicides are behind CKDu, the sugar cane industry has a responsibility to provide protection to laborers handling chemicals proved to be toxic over a period of prolonged exposure.

The sugar industry has conducted a number of internal studies in attempts to dissolve the suggested links between itself and the disease. A 2001 internal study conducted by Nicaragua Sugar Plantations found that “strenuous labour with exposure to high environmental temperatures without an adequate hydration programme,” were important factors in the development of CKDu. Yet, as Storr reports, the organization followed up these findings by announcing that: “We’re convinced that we have nothing to do with kidney disease. Our productive practices do not generate and are not causal factors for CKD[u].” In other words, even though the industry acknowledges that strenuous labor matched with dehydration may well contribute to CKDu, it has yet to change its practices and continues to deny any causal connection.

Furthermore, in another furtive attempt to dispel the growing association between itself and CKDu, the industry has begun firing laborers who show any sign of the disease. Both Storr and the New York Times reported that in order to disassociate themselves from the disease the industry requires that “workers take blood or urine tests that measure kidney function to determine whether they will be allowed to return to the fields.” The “complete dependence” on the industry in the rural areas surrounding sugar mills means that men desperate to support their families go to radical measures to remain employed. The Times reports that men often borrow their wives’ or children’s identity numbers in an effort to pass the blood or urine test.

The industry’s continued denial of even a possible association between sugar milling and CKDu is especially alarming in light of the fact that the recently announced CKDu research the Center for Disease Control (CDC) is looking to conduct is being entirely funded by the sugar industry.

While organizations like the National Institutes of Health (NIH) have poured millions of dollars (NIH currently spends $655 million on kidney research) into CKD research in the United States, the CKDu epidemic in developing countries has up until now been largely ignored. And worse still, global institutions, the World Bank amongst them, have funded the expanding sugar cane industry in Latin America without investigating the potential link between CKDu and sugar cane agricultural practices.            Therefore the CDC’s announcement that it will fund CKDu research would shine with promise were it not for the fact that the studies will be entirely funded by $1.7 million in donations from the Central American sugar industry — a profound conflict of interest.

However, a recent report released in March by the International Journal of Environmental Research and Public Health may make it harder for the industry to continue denying a link. The study found that glyphosate, a weed killer sold by Monsanto and marketed under the name Roundup,  “can become highly toxic to one’s kidneys when mixed with hard water.” Glyphosate is widely used in the sugar cane industry both as a chemical ripener and weed killer; it is but one example of the many widely marketed pesticides that when used incorrectly have been shown to contribute to kidney failure. In response to fears that the chemical may be causing CKDu when mixed with hard ground water, El Salvador followed in Sri Lanka’s footsteps and banned the use of glyphosate in 2013.

Not only does the use of chemicals like glyphosate pose a direct threat to laborers, but such chemicals pose an indirect threat through contamination to entire communities and ecosystems as well.

As sugar milling expands, so does the largely unmonitored use of agrochemicals like glyphosate, increasing the risk of contaminating water sources. The consequences of contamination are aggravated by the findings that glyphosate becomes toxic to the liver when mixed with hard ground water. If the findings prove correct, the use of glyphosate in sugar cane fields no longer poses a threat only to sugar cane workers but also to entire communities whose drinking water may be contaminated by glyphosate and other chemicals.

Storr reported that many sugar mills occupy low lying areas susceptible to flash flooding, and reported that some residents found the water to taste strange and salty. Even if glyphosate and other agrochemicals do not directly cause CKDu it is important to hold the sugar industry accountable to the proper use of chemicals to minimize the biological damage caused by water contamination and to ensure that the sugar we consume has been farmed responsibly.

As our sugar consumption continues to increase it is important that we turn our attention to the CKDu epidemic ravaging the communities that produce sugar cane. We must do so not only because their sugar-induced epidemics are due as much attention as ours, but also because our continued increase in consumption may mean an increase in affected communities.

As demand for sugar increases it will bring the profitability of the industry along with it; the sugar industry will continue taking over small towns across Central America. Until the link between CKDu and the sugar industry is proven or dispelled the industry’s unmonitored expansion means risking putting more poor, small Central American communities at risk of CKDu’s ravages.

Going forward we must ask ourselves if we wish to continue to consume a product whose very production process appears tied to a deadly illness, and whether we wish to continue to accept the use of pesticides on our food and land without challenge. We are no longer, nor have ever been, the only victims of our addiction to sugar. Reducing our national sugar intake, holding agrochemical companies accountable, and making sure that what we put in our bodies is responsibly farmed will not only make us healthier but will help the very people who labor exhaustively to put food on our tables at the cost of their own lives.