The Five Worst Packaged Lunchbox Meals: Factors

The Physicians Committee

The Five Worst Packaged Lunchbox Meals: Factors

A Report from PCRM's Cancer Project
Spring 2009

Findings | Key Factors | Rating System/Detailed Results | References

Key Factors

Here is more detailed information about the key factors in the Cancer Project’s evaluation process:

High fat content: Diets high in fat, especially saturated fat, have been linked by scientific research to increased risk of cancer, diabetes, and heart disease. High-fat, low-fiber foods boost the hormones that promote cancer. Specifically, diets high in meat, dairy products, fried foods, and vegetable oils cause an increase in the production of estrogens. Evidence suggests that high concentrations of estrogens in the bloodstream increase risk of cancer of the breast and other organs sensitive to sex hormones. High-fat, meat-heavy diets have also been linked to increased risk of colorectal cancer.

Cholesterol: Cholesterol is a waxy substance found in the bloodstream and in the body's cells. Every animal cell, whether from a human or any other animal, contains some of it. Blood-cholesterol levels are strongly linked to risk of heart disease. High levels of LDL, also known as “bad” cholesterol, and low levels of HDL, or “good” cholesterol, increase the risk of heart disease and stroke. Saturated fats are a major contributor to increased levels of LDL. Trans fats also increase LDL levels. Consuming large amounts of dietary cholesterol may eventually lead to reduced heart function.

Trans fats and partially hydrogenated oils: Partially hydrogenated oils are liquid oils that have been chemically hardened to make them more solid. They are often used as a preservative in snack foods to increase shelf life. Trans fats raise LDL-cholesterol levels and lower HDL-cholesterol levels, increasing the risk of cardiovascular disease.

Processed meats: Consuming processed meats—including hot dogs, pepperoni, bacon, and some deli meats—is a key risk factor for colorectal cancer, according to a comprehensive report released in 2007 by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund. After reviewing 58 published studies on nutrition and cancer risk, AICR scientists concluded that processed meats increase one’s risk of colorectal cancer by an average of 21 percent for every 50 grams of processed meat consumed daily. A 50-gram serving is approximately the size of a typical hot dog.

Dairy products: Dairy products, including milk, cheese, and yogurt, are typically high in fat and cholesterol, and researchers are discovering that dairy products appear to play an important role in cancer risk. In observational studies, dairy-product intake is associated with prostate-cancer risk. When humans drink cow’s milk—even skim milk or fat-free milk—it causes biological changes in the body, including a rise in the amount of insulin-like growth factor 1 (IGF-1) in the bloodstream. IGF-1 is a powerful stimulus for cancer-cell growth. In addition, milk appears to interfere with the activation of vitamin D in the body. Vitamin D helps the body absorb calcium from the digestive tract. It also protects the prostate against cancer. Dairy products may also increase the risk of ovarian cancer. Studies suggest that galactose, a byproduct of lactose digestion, may have a toxic effect on a woman’s ovaries.

Sodium: Diets high in sodium can increase the risk of high blood pressure, a condition that can lead to cardiovascular disease and kidney problems. A typical child aged 4 to 8 needs only 1,200 milligrams of sodium a day, according to the Institute of Medicine. But the average child in the United States consumes more than twice that amount. Processed foods often contain large amounts of sodium, and high sodium content in children’s food helps condition their taste buds so they develop a lifetime habit of consuming unhealthful levels of sodium.

Fiber: Diets high in fiber and low in fat help reduce the amount of estrogen circulating in the blood. Fiber is also important in preventing colon cancer, as it helps move food waste, extra hormones, and carcinogens out of the body. Fiber may help the immune system function properly. Building a diet from fiber-rich plant foods is important for cancer prevention and survival as well as overall health. Most Americans do not get enough fiber, and one key reason is that many commonly consumed dishes filled with meat, eggs, and dairy contain little or no fiber. On average, Americans currently consume less than half the recommended 35 grams to 40 grams of fiber per day.

Sugar: Simple, refined sugars provide calories but no nutritional benefit when it comes to cancer prevention and survival. Refined sugars are easy to overconsume because they are not filling. Therefore, they can promote weight gain, which increases the risk for certain types of cancer. In addition, some evidence suggests that elevated insulin levels resulting from consumption of refined sugars may increase cancer risk and impair survival. For these reasons, it is important to choose more healthful sweet foods, such as whole and dried fruits with cancer-fighting nutrients and fiber.