Sweet yellow corn (Zea mays var. saccharata) is a good source of zeaxanthin, melatonin, thiamin (vitamin B1) and pantothenic acid (vitamin B5) and also incorporates other B vitamins. Corn also contains meaningful amounts of alpha-carotene, beta-carotene, beta-cryptoxanthin, campesterol, ferulic acid, lutein, and insoluble fiber.

Breast cancer-related effects of eating corn

Corn and corn products

There is little available information concerning the relationship between the consumption of fresh corn, cornmeal, cornstarch or grits and breast cancer risk. Generally speaking, white corn incorporates less beneficial nutrients compared to yellow corn.
Corn and foods made from corn have a high glycemic index. Cornmeal, cornstarch and grits do not appear to promote breast cancer directly. However, one study found a link between increased starch intake after a diagnosis of early stage breast cancer and increased risk of recurrence. Corn oil is covered in a separate webpage.

Beneficial sweet corn compounds

Sweet corn contains some melatonin. Melatonin protects against ER+ breast cancer by reducing aromatase activity within the breast, thereby decreasing estrogen production. Melatonin has also been found to reduce triple negative (ER-/PR-/HER2-) breast cancer growth, proliferation and migration in cell and animal studies. In addition, melatonin has been shown to reduce the cardiotoxicity associated with Adriamycin (doxorubicin) chemotherapy. Sweet corn and field corn (used to make corn tortillas and corn chips) both contain zeaxanthin and lutein, which have been shown to have chemopreventive properties.

Purple and blue corn

Purple and blue corn are abundant sources of anthocyanins (primarily cyanidin-3-glucoside). The darker the corn, the higher the level of anthocyanins. Such corn anthocyanins have been shown to have potent antioxidant, anti-inflammatory, antimutagenic, anticarcinogenic, and anti-angiogenic properties. Blue corn and blue corn tortilla extracts have been shown to have antiproliferative effects against hormone receptor positive (ER+/PR+) and triple negative breast cancer cells.

High-fructose corn syrup

High-fructose corn syrup is a sweetener manufactured from cornmeal which is found in a wide variety of processed foods, for example, candy bars, packaged pastries, ketchup, ice cream, soda, and juice drinks. Diets elevated in high-fructose corn syrup have been linked to chronic inflammation, a breast cancer risk factor, as well as increased risk of triple negative breast cancer. High-fructose corn syrup has also been reported to worsen the cardiotoxicity induced by combined anthracycline chemotherapy and HER2-blocking agents.
Breast cancer cell metabolism is characterized by enhanced uptake and use of glucose. Fructose normally is barely metabolized in breast cancer cells. However, it has been demonstrated that when glucose is not available (i.e., the cells are in a state of glucose deficiency), fructose can be used instead by breast cancer cells. In addition, a 2024 study reported that the liver converts fructose into usable nutrients for cancer cells. These results suggest that a diet abundant in high-fructose corn syrup could promote the progression of breast cancer.

Additional comments

Functional fiber products

Fiber is added to some processed foods in order to qualify the foods as “high fiber” or to improve texture. This isolated or functional fiber is extracted or synthesized from plant sources. Examples include soluble corn fiber (from corn), inulin (chicory root or sugar beets), cellulose (wood pulp), maltodextrin (corn, rice, or potato starch) and polydextrose (corn starch). Such fiber-fortified foods typically lack the flavonoids and other biologically active components of the foods from which they are derived and may lack nutritional value, however there is no evidence that functional fiber is harmful.

Fungi and corn products

Various studies of non-U.S. populations have found that consumption of corn contaminated with fusarium fungi accounts for high levels of esophageal cancer in parts of Iran, Brazil, South Africa, and China. Fusarium fungi produce fumonisins that reduce to compounds that synthesize carcinogenic nitrosamines.
Fumonisins have been found to survive most types of baking and frying. Both fumonisin and aflatoxin levels are regulated by the Food and Drug Administration in corn meant for human consumption and in animal feed. However, one study of fresh corn and corn products sold in small family-owned markets in San Diego, California, detected zearalenone (a breast carcinogen which is produced by several species of fusarium fungi) in more than 70% of the samples tested.

Sources of information provided in this webpage

The information above, which is updated continually as new research becomes available, has been developed based solely on the results of academic studies. Clicking on any of the underlined terms will take you to its tag or webpage, which contain more extensive information.
Below are links to 20 recent studies concerning this food and its components. For a more complete list, including less recent studies, please click on corn.