Cancer fighting foods. Which foods, diets, and nutrition help reduce cancer risk.
In this article we’re going to look at:
- Functional foods for cancer prevention.
- Foods to avoid, and foods you thought you needed to avoid, but should not!
- To finish off, a few types of diets and how they can affect your cancer risk as well as help with prevention.
If you want to discuss cancer prevention, or integrative cancer care, you can always book a free consultation with Dr. Irina Chan, ND by clicking here.
What are Cancer fighting foods? Also known as Functional Foods?
Functional foods are foods that have been linked to lowering cancer risks. They work by improving the immune response, reducing inflammation, promoting detoxification, or protecting our DNA from oxidative damage.
In recent years there have been laboratory studies showing that these specific foods have been effective in either indirectly or directly blocking tumor growth.
In fact, you can find these types of food items on almost any grocery store shelf!
Some cancer fighting foods to incorporate into your diet include garlic, and this can also include leeks and onions. Garlic may help to prevent cancer by improving the immune response, reducing inflammation, detoxification, and protecting DNA from oxidative damage. Garlic intake is inversely associated with risk of stomach, colorectal, prostate cancer.
Cruciferous vegetables, including broccoli, kale, cabbage, cauliflower, and brussel sprouts contain sulforaphanes and isothiocyanates that may help to prevent cancer by improving detoxification and limiting the accumulation of excess hormones that can promote breast cancer or prostate cancer.
Cruciferous vegetable intake is inversely associated with risk of breast, kidney, bladder, lung, colorectal and prostate cancer.
Mushrooms, such as shiitake and maitake and even white button mushrooms are great to include in your diet of cancer fighting foods. Higher mushroom consumption is associated with lower risk of cancer stemming from their potent antioxidant properties. Mushrooms also contain β-glucans which have been implicated as having antitumor and immunomodulation properties. By improving our immunity, we are improving our body’s natural defense against cancer.
And lastly, green tea contains catechins, which are powerful antioxidants that have been shown to inhibit the growth and spread of tumor cells in laboratory studies. Green tea consumption has been shown to reduce the risk of oral, stomach, colorectal, lung, breast, ovarian and prostate cancer.
Oftentimes, I recommend having three to five cups of green tea a day.
Next, I’ll be covering some of the frequently asked questions associated with diet, nutrition and cancer risk.
I’m going to start off with soy. Oftentimes both men and women, are told to avoid soy because of its estrogenic effects. However, when you look into the research, soy consumption is associated with a reduction risk of breast cancer, as well as prostate cancer. Even in those who take it after their breast cancer diagnosis, it was shown to help prevent the recurrence. This is most likely due to soy binding to the estrogen receptors more weakly than estrogen itself. So when soy binds to the estrogen receptor, it actually inhibits estrogen from binding to these receptors. And that’s why we see a benefit here.
What about alcohol intake? Alcohol consumption increases risk for all cancers and the risk increases as you drink more. That means, that there is no safe amount of alcohol that can be consumed. There seems to be one exception. Higher consumption of wine seems to contribute to elevated breast cancer risk; however, lower doses (a third of a cup a day) does seem to have some protective effects, most likely due to the polyphenol and resveratrol content within the wine.
What about coffee? Coffee is good! Black coffee is actually rich in polyphenols which have protective effects against certain cancers like liver, endometrial, prostate, oral, and colorectal cancer. Just be mindful of what you’re adding to your coffee before drinking it (i.e. sugar and cream).
Should you be avoiding dairy? When it comes to cancer prevention, there seems to be inconsistent data on the consumption of dairy products in general. However, there seems to be protective effects associated with the consumption of fermented dairy products such as yogurt and cheese. If you would like to include dairy in your diet, it is best to choose organic products that do not contain residual antibiotics, hormones, and pesticides.
Are carbohydrates really that bad? Another big question is if one should avoid sugar and carbs. When you eat carbohydrates, they are broken down into sugars, which is the primary fuel source our cells use to give us enough energy to sustain our daily activities. But sugar in excess amounts can contribute to diabetes and weight gain, which is associated with the elevated risk of cancer.
Rather than eliminate carbs entirely from our diets, focus on reducing simple carb intake (e.g. white pasta, bread, white sugar, candy, desserts) and incorporate more complex carbs (e.g. fruits, vegetables, whole grains, beans) that can stabilize blood sugar levels and have additional cancer-fighting nutrients. If you have a sweet tooth, choose lower glycemic index options (less sugar spiking effect) such as dates, bananas, monk fruit, stevia, xylitol, raw honey, or coconut sugar.
What about eggs? Data is mixed. Some have failed to find an association, but some have found that consuming ≥ 5 eggs/week was significantly associated with an increased risk of breast, ovarian compared with no egg consumption. Men who consumed 2.5 or more eggs per week had an 81% increased risk of lethal prostate cancer compared with men who consumed less than 0.5 eggs per week.
Similarly, those who consumed >3 eggs a week had increased risk of gastrointestinal cancer compared to those who consumed <3 eggs a week. Based on these studies, perhaps it’s best to limit our egg intake to less than three or five a week. But more research is needed to confirm the cancer risks associated with egg consumption.
Intermittent fasting, is it all that? Intermittent fasting has really become a trend lately. In terms of cancer, preliminary studies have shown that prolonged fasting is safe and potentially capable of decreasing toxicity associated with chemotherapy, as well as having some benefit towards reducing tumor growth. Intermittent fasting may also be considered in adults seeking cancer-prevention benefits through means of weight management. However, intermittent fasting is not suitable for everyone especially if you have diabetes, unintended weight loss, fatigue, a history of disordered eating or mood disorders, or are pregnant or lactating.
Should I be vegetarian? A plant-based diet is best for cancer prevention. However, it is important to eat enough protein to meet your energy needs which may be challenging while on an entirely plant-based diet. Modest amounts of fish or white meats can help you meet your daily protein requirements and provide additional cancer-prevention benefits (such as omega-3).
Lastly, I want to touch on the keto diet. With the keto diet, there is currently no conclusive evidence to support its use for improved survival in cancer patients. There are risk factors associated with being on a keto diet, such as losing weight, headache, brain fog, fatigue, nausea, and constipation. It is also a diet that is challenging to adhere to.