There are mixed reviews from the scientific community regarding the association between foods and certain types of cancers; however, the consensus remains: eating a diet that is balanced, containing a variety of fruits and vegetables, combined with daily physical activity, is strongly encouraged and may protect against some diseases—even cancer.
Let’s look at some foods that have shown some possible associations with cancer reduction:
Cruciferous vegetables include green vegetables like collard greens, broccoli, Brussels sprouts, and cabbage, and veggies like cauliflower, radishes, rutabaga, turnips, and watercress.
Results from various studies have been mixed. A study across multiple countries found no risk reduction; one study from the United States found a weak association between vegetable intake and reduced breast cancer risk, while another study showed a reduction in breast cancer risk in women who ate greater amounts of such vegetables.
Reportedly, no association has been found between green leafy vegetable intake and a reduction in colorectal cancer. One exception to this is a study from the Netherlands in which females (but not males) who had a high intake of cruciferous vegetables were found to have a reduced risk of colon (but not rectal) cancer.
Most studies have found little association between the intake of green vegetables and decreased rates of lung cancer; however, one U.S. study found women who ate more than five servings of green vegetables per week had a decreased risk of lung cancer.
Studies from the Netherlands, United States, and Europe examined a variety of people who had daily intake of cruciferous vegetables and found little-to-no evidence to support that ingestion of these vegetables lowered the risk for prostate cancer. Conversely, some case-controlled studies found a reduction in the risk of prostate cancer in those who ate larger amounts of cruciferous vegetables.
Beta-carotene, found in carrots, supports the immune system and may provide cancer-reducing benefits.2
Breast and Prostate Cancer.
Studies have shown reduced risks of breast and prostate cancer to beta-carotene intake. Another study found a 26% reduced risk of developing stomach cancer when a larger amount of carrots were eaten.3
A study from 2018 in the Journal of Food and Drug Analysis suggested that eating apples may stop the growth of cells related to breast cancer.4
Colorectal and Other Cancers.
Apples contain 10% of recommended daily intake of fiber and vitamin C.5 The American Institute for Cancer Research (AICR) has found a probable correlation between a decreased risk of colorectal cancer and foods that contain fiber. They also found that fruits and non-starchy vegetables are likely to decrease the risk of many cancers, including lip, mouth, tongue, and digestive cancers.6 In addition to apples, other fruits that the American Institute for Cancer Research reports to be probable in reducing cancer include: blueberries,7 cherries,8 cranberries,9 grapes and grape juice,10 and grapefruit.11 Interestingly, grapefruit has also been studied as a fruit that aids in weight control. Being overweight or obese increases your chances of getting 12 types of cancers.12
Endometrial and Liver Cancer.
Strong evidence suggests that coffee has a high probability of reducing the risk of endometrial and liver cancer.13
According to the National Institute of Health, there are no definitive conclusions correlating any specific health benefits and green tea. The National Cancer Institute does not recommend for or against using green tea to reduce the risk of any cancer. Limited evidence suggests a potential benefit of both green and black tea in the reduction of blood pressure and cholesterol. Studies have found no meaningful weight loss in overweight or obese patients utilizing green tea extracts.14
Various facts and myths regarding the intake of other foods and drinks and cancer risk exist. For instance, there is no direct link between sugar intake (including artificial sweeteners) and the risk of developing cancer; however, a diet high in sugar will likely result in weight gain and obesity—making sugar an indirect link to cancer.15
Additionally, strong evidence supports that alcohol intake increases your risk of several cancers (mouth, pharynx, larynx, esophagus, liver, breast, stomach, and colorectum)—this includes small amounts consumed on a regular basis. The American Institute for Cancer Research does recognize that modest intake may provide protection against heart disease and type 2 diabetes and advises no more than one drink for women and no more than two drinks for men per day.16
Processed meat (i.e. sliced turkey, bologna, deli meats, bacon, ham, hot dogs) in ANY amount when eaten regularly increase the risk of colorectal cancer. The American Institute of Cancer Research recommends saving bacon and other processed meats for special occasions. Red meat (i.e. beef, lamb, pork) in amounts greater than 18 ounces per week has also been shown to increase the risk of colorectal cancer. The American Institute of Cancer Research recommends limiting the amount of red meat you eat and have meat-free days during the week.17
Test your knowledge regarding the impact of diet on cancer risk by completing this quiz: https://www.aicr.org/enews/2019/02-february-/enews-myths-and-facts-cancer-prevention-month-quiz.html