KANSAS CITY — A recently published study examining the connection between the consumption of bread and the risk of developing cancer has heightened importance because of scientific findings dating back 30 years. While the linkage between acrylamide and cancer risk has not prompted major changes in consumer behaviors, concerns about acrylamide continue to quietly smolder, threatening to engulf numerous foods, including bread and cereal products.
It was eight years after the World Health Organization in 1994 established a maximum threshold for the level of acrylamide in water that Swedish researchers made a bombshell announcement. They had discovered the presence of the suspected carcinogen in many commonly consumed foods, including bread, at levels far higher than the WHO deemed safe.
While the WHO guidelines implied intake of any more than 2 micrograms of acrylamide in water per day (0.5 micrograms per liter) was unsafe, the Swedish researchers discovered consumers purchasing medium french fries at a fast-food chain were ingesting about 30 micrograms or more per serving. Grain-based foods and coffee were other top dietary sources with 1 microgram of acrylamide per slice of white bread (about 10 micrograms in a piece of dark toast) and just under 0.45 micrograms in a cup of coffee.
In theory, the news was about as bad as could be imagined for the foods implicated. Given how easily many consumers flee products based on less-than-rock-solid research (think about high-fructose corn syrup), a wave of avoidance of acrylamide-containing foods could have been anticipated. In 20-plus years, no such reaction has materialized.
Major news sources counseled calm in 2002, with USA Today citing food scientists telling the public not to overreact. The New York Times said the importance of the findings had “yet to be determined.” Others sought to stir up fear. The Center for Science in the Public Interest called the Swedish findings “extremely worrisome.” So far, though, common sense has prevailed. Perhaps the absence of acrylamide on labels — in contrast, say, to HFCS — made a difference. More likely, consumers seemed to conclude that if acrylamide were truly that dangerous, the incidence of cancer would have been and would remain far higher among consumers of many staple products containing acrylamide for centuries.
At the same time, it would be wrong to call acrylamide a non-issue, even 22 years after its presence was discovered in food. The WHO still cautions exposure to acrylamide “should be reduced to as low a level as technically achievable.” Mindful of potential risk, numerous companies have explored ways, whether through reformulation or changes in cooking temperatures, to reduce acrylamide when possible. The compound is not an ingredient. It is formed in the production process — when french fries are cooked, when bread is baked/toasted, when coffee is roasted.
Also over the last two decades, myriad studies have been conducted looking for a linkage between acrylamide intake and the risk of cancer. Results have been inconclusive. A study just published in Current Developments in Nutrition looks head-on at research linking intake of bread and cancer. “Bread Consumption and Cancer Risk: Systematic Review and Meta-Analysis of Prospective Cohort Studies” was written by a team led by Glenn Gaesser, PhD, a professor at Arizona State University and chair of the Grain Foods Foundation Scientific Advisory Committee.
The team pored over studies that offered hazard ratios, a measure of risk, for bread consumption and cancer incidence or mortality. A total of 24 studies were reviewed, showing “bread consumption is not associated with increased cancer incidence or mortality.” The findings also applied to site-specific cancers, including colorectal, breast and prostate cancers. The researchers said looking at bread alone is worthwhile because it is a high-glycemic index food, and high GI diets also have been linked to cancer. With the acrylamide and GI issues continuing to hover over the health landscape, the researchers’ study represents a valuable affirmation that bread and other grain-based foods may be eaten with confidence.