With so many food "rules" and alarming media reports about food and food ingredients, you may be overwhelmed and confused about what to eat. Health experts agree that certain dietary behaviors—such as consuming plenty of fruits and vegetables—can reduce the risk of cancer. However, even with such easy to follow and well-publicized advice, consumers tend to perceive a risk of cancer from individual food ingredients with very little evidence to support that concern.When food is related to cancer risk, the problem is not necessarily about good versus bad food, but about poor eating habits. Nevertheless, consumers worry about what’s in their food—including suspected carcinogens, additives, or contaminants. That concern, however, may be out of proportion with the real risk.
In 1996 a prestigious scientific panel concluded that the real cancer risk in our diets comes not from the miniscule amounts of specific chemicals in our food but from how we eat. Americans trying to avoid potential cancer-causing substances in foods would benefit most from a diet that includes plenty of fruits and vegetables and one that’s not too rich in calories, fats, and alcohol.
The National Research Council report, Carcinogens and Anticarcinogens in the Human Diet, states that about one-third of all cancer deaths in the nation each year could be attributed to diet (excess caloric intake and excess alcohol consumption), but probably not, in significant numbers, to natural or synthetic chemicals.
Furthermore, the 1996 Harvard Report on Cancer Prevention (Volume I: Human Causes of Cancer) concluded that 65 percent of cancer deaths in the United States can be linked to tobacco use, diet, obesity, and a lack of exercise. Just one percent could be attributed to food additives and contaminants.
Despite these credible reports, the concern about suspected carcinogens in our food is still a hot topic today. Are these chemical compounds true risk factors?
Unfamiliar Compounds in Food
The following are a few of the chemical compounds making headlines and information about their potential cancer-causing potential.
Acrylamide
In April 2002, a group of Swedish scientists presented research that detected trace levels of a probable human carcinogen and neurotoxicant—acrylamide—in some baked and fried foods. Acrylamide is not added to food, but has recently been found to be a natural by-product of certain foods when they are processed or cooked.
New technologies and analytical methods have made it easier to detect acrylamide in foods. According to the U.S. Food and Drug Administration (FDA), acrylamide appears to be a result of baking, frying, or roasting at high temperatures and is believed to have been present in cooked foods for thousands of years. Acrylamide in food is not the result of contamination from environmental sources.
Scientists know that high doses of acrylamide cause cancer in laboratory rats. What is still unclear is whether the minute amounts of acrylamide in cooked foods may cause cancer or have any other harmful effects when people ingest it.
Foods found to contain varying amounts of acrylamide include coffee, fruits, vegetables, cereals, meats, and breads. According to FDA scientist Donna Robie, however, "No one food is contributing to the majority of the acrylamide (found in U.S. diets)."
FDA released exploratory data on acrylamide in late 2002 and early 2003. The agency has developed an action plan and continues to investigate how acrylamide is formed in food, identify ways to reduce acrylamide levels, and to study the human health risk of consuming acrylamide in foods.
Dr. Carl Winter, toxicologist and director of the FoodSafe Program at the University of California, Davis, notes that some animals can develop cancer when they are exposed to high doses of certain chemicals, but it is quite a leap to use the findings from those studies to project the cancer risk to humans, who are exposed to significantly lower doses of the chemical.
"We have a saying in toxicology, ‘The dose makes the poison,’" said Winter. "It’s the amount of a chemical—not its presence or absence—that determines the potential for harm. What’s much less clear is the health significance, if any, of our much lower levels of exposure to acrylamide in foods."
What should consumers do about acrylamide in food?
The FDA says consumers should not overreact or be alarmed and, until more is known, the agency continues to recommend that consumers eat a balanced diet, choosing a variety of foods that are low in trans fat and saturated fat, and rich in high-fiber grains, fruits and vegetables.
Semicarbazide
In October 2003, the European Food Safety Agency (EFSA) released a risk assessment regarding semicarbazide (SEM) in food. SEM belongs to a family of chemicals called hydrazines, which are known to cause cancer in laboratory animals. The agency reported that small quantities of SEM were found in a number of foods packaged in glass jars and bottles with metal lids with the typical plastic gaskets used to ensure an airtight seal. This seal protects the food from contamination by microbiological hazards, dust, insects, or other foreign objects. Such metal lids are used for products such as fruit juices, jams, honey, baby food, vegetables, sauces, and condiments.
Currently, FDA is examining foods and is continuing to assess the potential toxicity of SEM in food. Additionally, the food industry is working actively to reduce and, if possible, eliminate SEM from food packaging.
What should consumers do about SEM in food?
FDA said consumers should not avoid food packaged in glass jars. "At this time, FDA’s preliminary conclusion is that the levels of semicarbazide reported in foods in Europe are very low and present no risk to the public health."
The risk, if any, is very small for adults and for infants, according to EFSA. With current information, there is no reason for consumers—including infants—to change their dietary habits because of the possible presence of SEM in certain foods. Sealing gaskets for food containers have been used for many years and have helped protect the quality, wholesomeness, and overall safety of food products. An airtight seal offers product security and has helped provide packaging that maximizes product shelf life. Switching to alternative containers might not offer the same level of food safety and product quality.
Bisphenol A
Bisphenol A (BPA) is a chemical used to make polycarbonate plastic products such as reusable plastic food and drink containers, baby bottles, coatings of cans for food products, compact disks, sports safety equipment, and many common household products.
FDA regulates the use of BPA in food packaging. BPA has been extensively tested and proven to be safe by FDA and other regulatory agencies worldwide. It has been used in consumer products for more than 40 years.
What should consumers do about BPA in food?
BPA has been detected in some foods at extremely low levels (parts per billion). At these low levels, consumers would have to ingest hundreds of pounds of food and beverages (which have been in contact with polycarbonate) every day for an entire lifetime to exceed the safe level of BPA set by the U.S. Environmental Protection Agency. Therefore, consumers are not at significant risk from limited exposure to BPA from foods packaged in plastic containers or cans. On the basis of current research, there is no reason for consumers to change their choice of food items because of the possible presence of BPA in food.
Putting Cancer into Perspective
The possible link between cancer and unfamiliar compounds in food will continue to draw attention, but a report published in 2003 focuses instead on more healthful lifestyles and early-detection tests as a way to dramatically reduce cancer rates. Fulfilling the Potential of Cancer Prevention and Early Detection—from the Institute of Medicine of the National Academies, jointly presented with the American Cancer Society and other leading health groups—reports an estimated 60,000 deaths and 100,000 new cases of cancer could be prevented each year by 2015 if more Americans used the cancer prevention and early detection recommendations currently available.
The report says that smoking, poor diets, obesity, sedentary lifestyles, and failure to get early cancer detection tests all contribute to the excess burden of cancer. "Many of the behaviors placing people at increased risk for cancer are well recognized, and calls for change are not new," said Dr. John R. Seffrin, CEO of the American Cancer Society. "What is new, however, is the growing body of evidence confirming the effectiveness of interventions helping people improve their health-related behaviors."
Cancer rates are declining. Consumers who are worried about chemicals in food being potential causes of cancer should also be aware that death rates from the most common cancers (lung, breast, prostate, and colorectal) are declining, and the number of new cases is leveling off.
According to the Annual Report to the Nation on the Status of Cancer: 1975-2000, cancer death rates overall were stable from 1998 through 2000—that is, rates were neither increasing nor decreasing. The report, released in September 2003, said that the incidence rates for all types of cancers combined increased from the mid-1970s through 1992, declined from 1992 to 1995, and then stabilized from 1995 to 2000.
Additionally, U.S. life expectancy reached an all-time high of 77.4 years in 2002, according to the Centers for Disease Control and Prevention.
Reducing the Risk; Colorful Foods to Help Combat Cancer
A popular old phrase was "an apple a day keeps the doctor away." These days, it should be "five to nine a day may help keep cancer away."
For many years, government agencies and organizations that focus on health and cancer have been touting the powerful benefits of a diet high in fruits and vegetables. According to the National Cancer Institute (NCI), scientific findings continue to support the importance of eating more colorful fruits and vegetables because they may reduce the risk for certain types of cancer—as well as heart disease, hypertension, diabetes, and other diseases. "Colorful fruits and vegetables—provide essential vitamins, minerals, fiber, and several hundred unique disease-fighting phytochemicals that work together," said Lorelei DiSogra, EdD, RD, director of the 5 A Day Program at NCI. "Only fruits and vegetables, not pills or supplements, can provide all of these health benefits."
Although eating more fruits and vegetables could have a profound positive impact on the nation’s health, approximately 70 percent of American adults and children are not eating enough.
Many phytochemicals—natural plant substances—act as antioxidants to help reduce the risk of cancer. "Antioxidants are believed to protect cells from the damage caused by free radicals which can damage cell DNA and theoretically lead to cancer cells," said DiSogra. "Free radicals are produced as a normal part of metabolism, but antioxidants counteract free radicals and block them from doing any harm.
"A diet rich in fruits and vegetables will also be rich in antioxidants," said DiSogra. "Some examples of antioxidants are vitamin C (found in citrus fruits), vitamin A (found in sweet potatoes and carrots), lycopene (found in tomato sauce), flavonoids (found in berries), sulforophane (found in broccoli, cauliflower, cabbage, Brussels sprouts), and lutein (found in dark leafy greens)."
DiSogra said that it’s easy to eat five to nine servings of fruits and vegetables a day because servings are much smaller than people think. One serving is one medium-sized fruit, 1/2 cup of vegetables or fruit (raw, cooked, canned or frozen), 1/4 cup of dried fruit, 3/4 cup of 100 percent juice, or one cup of leafy greens.
Resources for Cancer Prevention and Nutrition
