No foods protect people against cancer completely. The term cancer-fighting foods refers to foods that may lower the risk of developing cancer if a person adds them to their diet.

This article looks at the best cancer-fighting foods and explains the science that supports these claims. Foods that contain naturally occurring compounds that have potent anticancer properties include:

1. Apples
The phrase "an apple a day keeps the doctor away" actually rings fairly true. Apples contain polyphenols that have promising anticancer properties. Polyphenols are plant-based compounds that may prevent inflammation, cardiovascular disease, and infections.

Some research suggests that polyphenols possess anticancer and tumor-fighting properties. For example, the polyphenol phloretin inhibits a protein called glucose transporter 2 (GLUT2) that plays a role in advanced-stage cell growth in certain types of cancer. One study from 2018 in the Journal of Food and Drug Analysis suggests that apple phloretin significantly inhibits the growth of breast cancer cells, while not affecting normal cells.

2. Berries
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.

One study shows that anthocyanin, which is a compound in blackberries, lowers biomarkers for colon cancer. Another study demonstrates that the anti-inflammatory effects of blueberries can prevent the growth of breast cancer tumors in mice.

3. Cruciferous vegetables
Cruciferous vegetables, such as broccoli, cauliflower, and kale, contain beneficial nutrients, including vitamin C, vitamin K, and manganese. Cruciferous vegetables also contain sulforaphane, a plant compound with anticancer 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 soybeans, can significantly inhibit breast cancer tumor development and size. Sulforaphane also inhibits histone deacetylase, an enzyme with links to cancer development. One review recommends 3 to 5 servings of cruciferous vegetables per week for the best cancer-preventive effects.

4. Carrots
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 distinct orange color. Recent studies reveal that beta-carotene plays a vital role in supporting the immune system and may 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% lower risk of developing stomach cancer.

5. Fatty fish
Fatty fish, including salmon, mackerel, and anchovies, is rich in essential nutrients, such as vitamin B, potassium, and omega-3 fatty acids.

One study found that people whose diets were high in freshwater fish had a 53% lower risk for colorectal cancer than those low in freshwater fish. Another study found that consumption of fish oil later in life has links to significantly lower risk for prostate cancer. Finally, a study following 68,109 people found that people who consumed fish oil supplements at least four times a week were 63% less likely to develop colon cancer than those who did not.

6. Walnuts
According to the American Institute for Cancer Research, all nuts exhibit cancer-preventing properties, but scientists have studied walnuts more than other types of nut.

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 one animal study, mice receiving whole walnuts and walnut oil had higher levels of tumor-suppressing genes than the mice receiving vegetable oil.

7. Legumes
Legumes, such as beans, peas, and lentils, are high in fiber, which may help lower a person's risk of developing cancer.

One meta-analysis of 14 studies shows an association between higher legume consumption and lower risk of colorectal cancer. Another study examines the relationship between the intake of bean fiber and risk of breast cancer. The study results indicate that people who ate diets high in bean fiber were 20% less likely to develop breast cancer than those who did not meet their daily fiber intake.

8. Supplements and medications
Although the foods listed above are everyday products and readily available, some people may not want to make significant dietary or lifestyle changes. In this case, there are plenty of supplements and medications available that contain anticancer compounds.

Vitamins A, C, and E are notable for their anticancer properties and are available as supplements in most major grocery stores. Most of the plant-based compounds listed throughout this article, such as phloretin, anthocyanin, and sulforaphane, come in pill form.

Over-the-counter medications, such as aspirin and ibuprofen, may also lower the risk of cancer in some people. Always speak to a medical professional before starting a new medication or supplement regimen.

Takeaway

Research into preventing cancer through diet is still in the early stages and requires further testing. Scientists carried out most of the studies mentioned in cells or mice. However, it is important to remember that eating a balanced diet high in fresh fruits, vegetables, and good fats will benefit overall health.