In April 2002, when a new study proclaimed that potato chips, corn chips and French fries contained a potential cancer-causing agent called acrylamide, a lot of people dropped their snacks and fast food with a collective thud. Then, almost as suddenly as the tabloid headline “French Fries Cause Cancer” had appeared, the story quietly moved to the back page. The big scare quickly dwindled to mild concern as a subsequent study downplayed the dangers of acrylamide. “No need to change your eating habits,” came the reassuring word from government spokespersons.
Some suspected that the powerful fast-food industry, in reaction to lagging sales, had the story swept under the rug. Some blamed other PR-sensitive food manufacturers for the sudden downshift. Many health experts insisted that the initial reports were simply overblown and that the more moderate stance was practical.
Today, acrylamide is still present in our food and no one seems entirely confident of whether or not the public should be concerned. The Food and Drug Administration (FDA), World Health Organization (WHO) and other health authorities are taking a wait-and-see approach and have recommended more studies. Until then they have reinforced a commonsense philosophy of maintaining a healthy, well-balanced diet that includes plenty of fruits and vegetables. And, oh yes — cut back on food that may contain acrylamide just to be safe. Not the most reassuring statement.
Of course, steering clear of French fries and other high-calorie, high-fat foods that are high in acrylamide is wise for a variety of reasons. But the study conducted by scientists with the Sweden National Food Administration also revealed that significant amounts of acrylamide are also present in many baked foods, including snacks such as baked chips and crackers, and in seemingly nonthreatening foods such as bagels, bread, cereal, roasted coffee, baby food and even home-cooked meals.
So what’s the true story? Is acrylamide really a threat? A closer examination of this mysterious chemical and its presence in our food shows that these are not at all easy questions to answer.
Examining the Evidence
The Swedish researchers who conducted the study in question were examining the health risks for workers exposed to acrylamide in their work environments. Acrylamide is used in the production of plastics found in some cosmetics, in food-packaging materials (such as paperboard) and in soil-conditioning and grouting agents.
Acrylamide is also used in the construction of dam foundations and tunnels. Acrylamide had long been designated as a cancer-causing agent in animals and a neurotoxin in humans, having caused nerve damage in people who were exposed to it in the workplace. FDA researchers also had found that acrylamide could damage DNA, often the first step toward cancer development.
The surprising aspect of the study was that the control group, which was not exposed to acrylamide at work, showed evidence of high levels of the chemical. This chance finding triggered an examination into the possible presence of acrylamide in the control group’s regular diet. Prior to the Swedish study, food was never checked for acrylamide because the chemical is not used as an added ingredient in prepared foods, nor was it known to be a component in any natural foods.
What caused the presence of acrylamide in the control group’s food? It wasn’t so much any specific foods that were the culprit — although that did play a role — but rather how the foods were prepared. The Swedish team discovered that certain starchy foods, such as grains, bread, rice, root vegetables and potatoes, when cooked at temperatures above 248 degrees F (120 degrees C) in processes such as deepfrying, roasting or oven baking, contained various amounts of acrylamide. Acrylamide was found in precooked, packaged and processed foods, as well as in meals cooked in the home. The levels of acrylamide varied widely among different products and foods, but generally the amount rose in correlation to the increased cooking time.
Researchers at the Nestlé Center in Switzerland and Britain’s University of Reading believe acrylamide compounds are formed in food as the result of something called the Maillard reaction. The Maillard reaction occurs when asparagine, an amino acid found in certain grains and starches, reacts with sugars under exposure to high heat.
Little is known about how acrylamide affects humans through food. It is classified as a neurotoxin, but only at doses considerably higher than would be encountered from consumption of foods that contain acrylamide. Even as a carcinogen it lacks punch and is rated by the International Agency for Research on Cancer as class 2A: “probably carcinogenic to humans.”
Despite this, in the Swedish study’s wake, the FDA tested the level of acrylamide in more than 275 common foods, such as roasted coffee, baby food, vegetarian burgers and breakfast links, fish sticks, cereals, snack foods, pretzels, nuts, cookies, crackers, baking chocolate, cocoa powder and soup mixes.
Several findings from the FDA tests stood out. First, acrylamide was found in a wide range of foods, and the amounts varied from brand to brand. For instance, acrylamide levels in 12 types of frozen French fries ranged from about 3.4 micrograms to 37 micrograms of acrylamide per 6-ounce serving. (To see how specific brand names tested, check out the FDA Web site, http://www.fda.gov/Food/FoodSafety/FoodContaminantsAdulteration/ChemicalContaminants/Acrylamide/default.htm.)
Also, some so-called healthier foods (baked versus fried) scored high amounts of acrylamide. Baked foods are generally considered healthier than fried foods because they are produced with little or no saturated fat, trans-fatty acids and hydrogenated oils. Still, the FDA examination showed that, depending on the brand, the levels of acrylamide in baked chips often exceeded those found in fried chips.
By the Numbers
So the million-dollar question remains: Does acrylamide pose a real health threat? Just because it shows up in some foods doesn’t necessarily mean the quantities pose any danger, and no one knows yet how much we would have to eat on a regular basis to put ourselves at risk.
Despite this ambiguity, some preliminary guidelines for intake restrictions have been drafted. The Environmental Protection Agency (EPA) has already determined safe levels for acrylamide in water. Because acrylamide is sometimes used in the treatment of drinking water, the EPA requires water suppliers to limit it to no more than 0.12 micrograms per 8-ounce glass.
There are no such regulations when it comes to food. The FDA has maintained that not enough is known about acrylamide formation to identify the necessary modifications to food-processing techniques. Instead it provided a recommendation for maximum daily intake. In June 2002, the FDA announced that 12 micrograms of acrylamide daily per person is safe in terms of effects to the nervous system.
Easier said than done. The nonprofit Center for Science in the Public Interest (CSPI) estimates that the average American consumes about 36 micrograms per day. Richard Forshee, PhD, director of research at the Center for Food and Nutrition Policy at the Virginia Polytechnic Institute and State University in Alexandria, says that men age 30 to 64 consume on average about 32 micrograms of acrylamide per day, while women in the same age group consume about 46 micrograms per day.
CSPI has petitioned the FDA to set “interim acceptable levels” for acrylamide in each category of food, the first U.S. proposal to require food companies to reduce acrylamide in their products. Yet there is some evidence that suggests such regulations might not even be necessary. A study conducted by researchers from the Harvard School of Public Health and the Karolinksa Institute in Stockholm, Sweden, studied the diets of 987 cancer patients and 538 healthy people and found no significant link between a history of high and moderate intake of acrylamide in 14 different types of food and the development of bowel, kidney or bladder cancer. The reaction to this study, published in the British Journal of Cancer (Jan. 13, 2003), has been split. Some experts have since waved off acrylamide as nothing to be concerned about.
“There is a general feeling that acrylamide is not a significant health risk,” wrote the British researchers. Others are more careful in their language and say we can probably be reassured that acrylamide levels that people are generally exposed to through food don’t appear to increase the risk of these three specific types of cancers.
But the CSPI released a statement soon after that, saying the study was inconclusive because the three cancers studied — bladder, colon and kidney — are not the ones that acrylamide causes in animals. (Acrylamide has been shown to cause lung, testicular, breast, uterine and other cancers in animals.) At the same time, even though there appears to be no evidence that acrylamide causes cancer in humans, “exposure to acrylamide should be as low as reasonably practical,” according to the U.K.-based independent Committee on Carcinogenicity of Chemicals in Food. The overall message seems to be this: Don’t worry until further notice.
For the time being, acrylamide seems to be stuck somewhere between something to fear and something to ignore. It belongs to the group of chemicals thought to have no reliably identifiable threshold of effects, meaning that very low concentrations will also result in very low risks, but not zero risk, according to the WHO. Of course, some risk is always present when acrylamide is ingested, and that risk goes up with increased exposure.
Until more research is completed (and much is in the works) there are some obvious steps we can take to protect ourselves: 1. Avoid fried foods; 2. Steam vegetables or boil if you must (neither method has been shown to trigger acrylamide formation); 3. Limit intake of processed snack foods; 4. Eat more raw vegetables, nuts and fruits.
Of course, this is a lot of the same advice you’d follow for general good health anyway, which in many ways makes avoiding acrylamide a “two birds with one stone” proposition. The final decision, though, is left up to the consumer. Until the experts provide more advice, all our tempting baked and fried-food favorites will continue presenting us with a healthy helping of doubt.
Alison Levitt, MD, is board-certified in family medicine, a Wise-Medicine advocate and an integrative medicine specialist.