No food completely protects people against cancer. The term cancer-fighting foods refers to foods that can reduce the risk of developing cancer if a person adds them to their diet.
The phrase “an apple a day keeps the doctor away” actually rings true enough. Apples contain polyphenols that have promising anti-cancer properties. Polyphenols are plant-based compounds that can prevent inflammation, cardiovascular disease, and infections. Some research suggests that polyphenols possess anticancer and tumor-fighting properties. For example, polyphenolphloretin inhibits a protein called glucose transporter 2 (GLUT2) that plays a role in late-stage cell growth in certain types of cancer. A 2018 study in the Journal of Food and Drug Analysis suggests that apple phloretin significantly inhibits the growth of breast cancer cells, while it does not affect normal cells.
Berries are rich in vitamins, minerals, and dietary fibers. Scientists have shown a lot of interest in berries due to their antioxidant properties and potential health benefits. A study shows that anthocyanin, which is a compound in blackberries, reduces biomarkers for colon cancer. Another study shows that the anti-inflammatory effects of blueberries can prevent the growth of breast cancer tumors in mice.
Cruciferous vegetables, such as broccoli, cauliflower, and kale, contain beneficial nutrients, such as vitamin C, vitamin K, and manganese. Cruciferous vegetables also contain sulforaphane, a plant compound with anti-cancer properties. One study shows that sulforaphane significantly inhibits cancer cell growth and stimulates cell death in colon cancer cells.
Another study shows that sulforaphane in combination with genistein, a compound in soy, can significantly inhibit breast cancer tumor development and size. Sulforaphane also inhibits histone deacetylase, an enzyme linked to cancer development. One review recommends 3 to 5 servings of cruciferous vegetables per week for the best cancer-preventive effects.
Carrots contain several essential nutrients including vitamin K, vitamin A, and antioxidants. Carrots also contain high amounts of beta-carotene, which is responsible for the distinctive orange color.
Recent studies reveal that beta-carotene plays a vital role in supporting the immune system and can prevent certain types of cancer. A review of eight studies shows that beta-carotene has links to a reduction in the risk of breast and prostate cancer. Another analysis shows that higher consumption of carrots results in a 26 percent lower risk of developing stomach cancer.
Fatty fish, including salmon, mackerel, and anchovies, are rich in essential nutrients, such as B vitamins, potassium, and omega-3 fatty acids. One study found that people whose diets were high in freshwater fish had a 53 percent lower risk of colorectal cancer than those low in freshwater fish. Another study found that future fish oil consumption has links to a significantly lower risk of prostate cancer.
Finally, a study after 68,109 people found that people who took fish oil supplements at least four times a week were 63 percent less likely to develop colon cancer than those who did not.
According to the Institute for Cancer Research, all nuts exhibit cancer-preventing properties, but scientists have studied nuts more than other types of nuts. Walnuts contain a substance called pedunculagin, which the body metabolizes into urolithins. Urolithins are compounds that bind to estrogen receptors and may play a role in preventing breast cancer. In an animal study, mice given whole nuts and nut oil had higher levels of tumor suppressor genes than mice given vegetable oil.