The concept of using food as medicine is nothing new. For literally thousands of years, human beings have used food to cure and prevent a host of ailments. But can nutrition fight cancer? While there are no guarantees, research indicates that dietary choices can indeed increase or decrease our risk of developing cancer. So, without further ado, here’s our list of the top cancer fighting foods.
Omega-3 Fatty Acids
Recent studies suggest that one third of cancers are preventable by reducing consumption of omega-6 fatty acids and increasing omega-3 fatty acid intake. While omega-6 fatty acids promote inflammation and cell growth, omega-3 fatty acids are anti-inflammatory and inhibit cell growth. This makes them useful in the treatment as well as the prevention of cancer.
An omega-6 to omega-3 ratio between 4:1 and 1:1 is considered ideal, but the average American’s diet is closer to 20:1. The most important omega-3 fatty acids are alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). ALA is found predominantly in plant sources, while fatty cold water fish such as salmon and mackerel are the best sources of DHA and EPA. While the human body can synthesize DHA and EPA from ALA, conversion is not very efficient, especially in men (on average, men are able to convert 5-10% of ALA to DHA and EPA, compared to 10-30% for women, and some men aren’t able to synthesize DHA at all). This means that you should get at least some of your omega-3 fatty acids from oily fish. Additionally, fish is a good source of vitamins A and D, which also help protect against cancer.
Another problem with getting omega-3 fatty acids from plant sources is that many of the foods highest in ALA are also high in omega-6 fatty acids. Canola oil, soybeans and soybean oil, hemp seeds and hemp oil, pumpkin seeds, walnuts, and butternuts are good sources of omega-3 fatty acids, but all of them are significantly higher in omega-6 fatty acids than omega-3s. Flax seeds and flax seed oil, however, contain three times more omega-3 fatty acids than omega-6 EFAs, and can easily be added to everything from baked goods to smoothies. Buying omega-3 fortified eggs and meats from grass-fed animals can also increase your omega-3 fatty acid consumption, but since meats are always higher in omega-6 EFAs than omega-3 EFAs, it’s best to eat more fish and less meat.
Dark Green Leafy Vegetables
Vegetables such as Swiss chard, romaine lettuce, spinach, arugula, beet greens, mustard greens, chicory, and other leafy greens are chock full of powerful antioxidants including beta-carotene, zeaxanthin, and lutein that fight dangerous free radicals to prevent early cancer development. Moreover, leafy greens are rich in folate. This is important because people with diets low in folate have higher rates of cancer, and some studies suggest that a folate rich diet reduces the risk of lung and breast cancer, in particular. Leafy greens are best eaten raw as a salad or lightly cooked to ensure that they retain most of their nutrients.
Cruciferous vegetables include broccoli, cabbage, arugula, Brussels sprouts, cauliflower, kale, collard greens, radishes, kohlrabi, bok choy, mustard greens, watercress, and other veggies in the cabbage family. In addition to being rich in free radical scavenging antioxidants, these vegetables contain the phytochemicals isothiocyanate and sulforaphane. These phytochemicals stimulate the production of enzymes that break down and destroy carcinogens. The anti-cancer benefits of broccoli and other cruciferous vegetables have been proven in a myriad of studies. Moreover, many cruciferous vegetables contain a indole-3-carbinol, a compound that can lower the risk of hormone related cancers such as breast and prostate cancer. For best results, eat four or more servings a week and be careful not to overcook your veggies.
The allium family includes garlic, onions, leeks, and chives. Studies indicate that the allium compounds is these foods can slow and possibly even stop the growth of tumors. Garlic, in particular, has been shown to be a powerful cancer preventative, dramatically reducing the risk of a number of cancers, specifically stomach, colon, and prostate cancer. For best results, garlic should be minced ten minutes prior to cooking.
Raspberries, strawberries, blueberries, blackberries, and cranberries are a delicious way to add cancer fighting foods to your diet. Berries contain a number of anti-cancer properties. Ellagic acid, which is present in many berries (the highest concentrations are found in raspberries and strawberries), acts as an antioxidant and has been proven to slow the growth of cancer cells. Berries also contain phytochemicals–specifically the polyphenols anthocyanidin and proanthocyanidin–that induce apoptosis (cell death) in cancer cells. Blueberries are particularly rich in anthocyanidins.
Beans and lentils fight cancer in two ways: They contain high levels of phytochemicals proven to slow or prevent cell damage, and their substantial fiber content helps remove toxins from the gastrointestinal tract and is associated with a decreased risk of digestive cancers such as colorectal cancer. Try to get at least thirty grams of fiber a day, and make sure to drink plenty of fluids with your fiber-rich meals.
Shiitake and maitake mushroom extracts are routinely prescribed to cancer patients in Asia, particularly in Japan, but you don’t need to take them in extract form to benefit from their cancer-fighting properties. A strong immune system is necessary for cancer prevention and treatment, and these mushrooms have been proven to stimulate immune function in a number of studies. They activate the body’s own cancer defenses by stimulating interleukins, tumor necrosis factor (TNF), and natural killer cells (NK). Mushrooms are also an excellent source of the powerful antioxidant L-ergothioneine. In addition to the aforementioned shiitake and maitake mushrooms, oyster and king oyster mushrooms have the highest levels of L-ergothioneine, but portabellas, criminis, and white buttons are also good sources of this amino acid.
Tomatoes are an excellent source of the carotenoid lycopene, a phytochemical that has been proven to drastically lower the risk of prostate cancer (men who ate ten servings of tomatoes per week reduced their prostate cancer risk by 45%). Regularly eating tomatoes also helps protect against other hormone dependent cancers (breast cancer, cervical cancer, ovarian cancer) as well as cancer of the mouth, lung, pancreas, stomach, and colon. Lycopene is more easily absorbed if tomatoes are eaten in cooked form. Try a zesty marinara sauce with lots of freshly minced garlic to boost the cancer-fighting potential of tomatoes.