High-fructose corn syrup is a hot topic in the national debate on diet, with opponents attacking it, as Daniel Engber has suggested, as unhealthy, unnatural and unappetizing, while corn refiners have volleyed back that it's safe, natural and tasty. Now the food additive has been implicated in the decline of another maker of sweeteners — honeybees.
Although researcher Blaise W. LeBlanc agrees that colony collapse disorder in honeybees probably results from a variety of environmental stresses such as mites, pesticides and infections (like Nosema ceranae), his recent, published experiments target a toxic byproduct of high-fructose corn syrup, which besides being an ingredient in processed human foods such as cereals, whole wheat bread and beverages, is also used as a nutritional supplement for bees.
LeBlanc, a former research chemist with the U.S. Department of Agriculture in Tucson and currently an instructor at nearby Pima Community College, identified the byproduct hydroxymethylfurfural, or HMF, as a potential culprit in colony collapse disorder.
He found that under four different temperatures (ranging from 89 degrees F to 156 degrees F), high-fructose corn syrup degraded enough in bees to cause ulceration and dysentery; above 120 degrees F, HMF levels doubled and bee deaths multiplied dramatically as observed in colony collapse. The syndrome is a serious threat — it destroyed 28.6 percent of total managed U.S. honeybee colonies, according to a survey from fall 2008 to spring 2009, and that followed more severe losses the two winters before.
Experts speculate that high-fructose corn syrup in the human food chain also may lead to disastrous consequences such as diabetes and obesity. "Swedish researchers found HMF in the urine [of people]," says LeBlanc. They also found DNA damage at higher HMF levels. German researchers, meanwhile, suggest HMF may act as a carcinogen in mice.
LeBlanc has a solution to minimize HMF toxicity: By adding bases (such as sodium bicarbonate, or baking soda, lime, potash or caustic soda) to HFCS, the pH (acid-alkaline balance) rises and, more importantly, HMF levels drop.
That more beekeepers do not apply this strategy is a negative LeBlanc blames on poor networking, weak communication, regional factors and the lack of academic regard for the non-peer-reviewed American Bee Journal as well as the shortage of funds for exploratory research (despite the USDA's appropriation of $20 million over the next five years). "A lot of issues could be cleared up at professional meetings," says LeBlanc, "if scientists completed surveys regarding environmental factors like native and invasive plants, temperature and diet."
Despite these impediments, the prevailing wisdom is to strengthen the honeybee's immune system by going "organic" as much as possible (there had been unsubstantiated reports organic colonies were not seeing colony collapse). Last month's federal court ruling revoking EPA approval of the toxic bee pesticide spirotetramat (sold as Movento and Ultor) — resulting from a suit brought by the Natural Resources Defense Council — may help to propel the industry in a healthier direction.
"The era of protein shakes for bees is here," writes Rowan Jacobsen, author of Fruitless Fall: The Collapse Of The Honeybee And The Coming Agricultural Crisis.
And why not boost this culinary "cocktail" with essential oils, ask scientists Margaret T. Chen, an adjunct member of the Vaccine Research Institute of San Diego, and Rance B. LeFebvre of the Veterinary School, University of California, Davis, who believe oils such as menthol, clove and cinnamon can ward off pests and strengthen bees' stomachs. LeBlanc recently confirmed the efficacy of carvacrol and thyme at controlling the Varroa mite and will study the combined effect on small hive beetles, another nuisance to bees.
All well and good, writes Dhruba Naug, assistant professor at Colorado State University in Fort Collins and author of a recent paper in Biological Conservation. But what if nutritional stress due to habitat loss is the "tipping point" for the deadly multi-stressor "synergistic effect" that culminates in colony collapse disorder? Naug's solution is straightforward: Preserve more open cropland and rangeland.
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