Cancer is the #2 killer in the United States, and diet may be the #1 cause of cancer (see also here, here, here). Why might doctors not know this? Because they may have never learned about it (see also here).
The balance of evidence suggests that whole food, plant-based diets may help prevent (see also here, here, here, here, here, here, here), treat, slow (see also here), and even reverse cancer progression (see also here). It’s never too late to start eating healthier, as cancer risk can drop after starting a plant-based diet at any age. Some reasons why plant-based diets may be effective include lowering methionine intake (see also here and here), inhibiting angiogenesis, intercepting carcinogens, and increasing the consumption of fiber (see also here and here) and antioxidants. Populations eating diets centered around whole plant foods have lower rates of cancer. Eating lots of fruits and vegetables—at least 9 daily servings (despite flawed studies to the contrary) may boost detoxifying enzymes, lower inflammation, lower cholesterol, and make for healthier bowel movements (here too), ridding oneself of excess estrogen and cholesterol (see also here).
On the other hand, meat consumption may increase the risk of cancer (especially processed meats (here, here)—something of which the meat industry is aware), increase risk of death, and decrease cancer survival (here, here). Cooking meats produce estrogenic carcinogens called heterocyclic amines (see also here). Smoked fish also contains high levels of carcinogenic compounds. Boiling meat, however, may lower exposure these toxins. Eggs and cheese may produce heterocyclic amines as well. Even inhaling the vapors from cooking meat (such as bacon see also here) or coming in contact with farm animals may pose a risk. Cholesterol found in animal products has been linked to increased breast cancer risk. Unfortunately, statin drugs (cholesterol lowering drugs) are also associated with a higher risk.
Another reason meat consumption is associated with an increased cancer risk could be the Neu5Gc molecule found in meat that may be triggering inflammation. Certain tumors thrive in an inflammatory setting, so our immune system might be feeding tumor growth (see also here). Another explanation for the association of meat and cancer is insulin-like growth factor (IGF-1) which has been linked to cancer based in part on studies of Laron Syndrome (a type of dwarfism). Those eating plant-based diets have less IGF-1, because the consumption of animal protein increases the levels of IGF-1. Though IGF-1 is an anabolic protein, blood levels are not associated with improved muscle mass. Soy consumption might not lower or raise the levels of IGF-1, depending on the quantity consumed (see also here). Vegans have lower levels of IGF-1 even when compared to endurance athletes. The heme iron found in the blood and muscle tissue of animal foods may also increase risk of cancer.
Poultry may significantly increase one’s risk for a variety of blood cancers, perhaps due to the dioxins (which are also found in U.S. farm raised catfish), drugs, or viruses in chicken meat. Chicken meat may also contain arsenic (see also here and here) and carcinogenic heterocyclic amines (especially when grilled). Poultry may increase the risk of liver, pancreatic, and penis cancer and cause warts if handled raw (see also here). Choline in eggs has been linked to increased risk of prostate cancer. Cows’ milk contains hormones (especially skim) that may promote cancer regardless of whether it’s organic or not (see also here). Dairy accelerates the aging enzyme, TOR, which may leads to a higher risk of cancer. Both meat and dairy may also contribute to melatonin suppression, which is associated with increased cancer risk.
Animal protein intake may increase the risk of premature puberty due to chemical pollutants in meat, which may put children at higher risk for cancer later in life. Once one is diagnosed with cancer, cutting down on saturated animal fat may improve cancer survival. A neutropenic diet (one devoid of fresh fruit and vegetables) does not help those undergoing chemotherapy, but oatmeal lotion may help with chemotherapy induced rashes. On the other hand, soy foods contain phytoestrogens, which may help prevent premature puberty and have been shown to both help prevent breast cancer and improve breast cancer survival (see also here). Although the relationship between GMO soy and breast cancer remains under-studied.
Green tea and many herbal varieties may also be protective (see also here). Among fruits, berries may be the best for cancer prevention, in part because they may help block cell-DNA damage. Organic strawberries and other fruits appear to work better than conventional (see also here, here and here). Cranberries are especially effective at fighting cancer, at least in a petri dish (see also here). See #1 Anticancer Vegetable (and the prequel Veggies vs. Cancer) for a comparison of the cancer-fighting properties of a wide array of vegetables in vitro. Broccoli might be the best vegetable for fighting breast cancer.
Other foods that have been associated with anti-cancer properties in general are broccoli (here, here, here, here, here, and here), greens, Indian gooseberries (against cancer cell growth and invasion), dragon’s blood, chili peppers, nuts (especially walnuts see also here, here), coffee, cocoa, red rice, black beans and beans in general, fiber in general, black pepper, mushrooms (especially white button see also here, here), flax seeds (especially with regards to for prostate cancer and breast cancer see also here, here, here, and here), Ceylon cinnamon, apples (especially their peel), tomatoes, the seaweed nori, strawberries, black raspberries, blueberries, garlic, sweet potatoes, and small amounts of licorice. Populations eating a lot of turmeric have lower cancer rates, and turmeric has been shown to block carcinogens (especially in colorectal cancer, multiple myeloma, and pancreatic cancer) and reprogram cancer cell death, and has even be used as a topical cancer treatment. Phytates in beans have also been shown to prevent, treat, and rehabilitate cancer cells in preclinical studies. Also make sure to get an hour of exercise every day (see also here), sleep 7-hours every night, and reduce one’s exposure to tanning beds, cell-phone radiation, CT scans, and dental x-rays. Meditation may also improve DNA health, preventing premature shortening of our telomeres.
Vitamin C pills, folic acid, multivitamins and some other supplements including iron and lutein, homeopathy, and Ayurvedic supplements may be useless or worse. Exposures known to increase cancer risk include alcohol (see also here – although some grapes in red wine may prove beneficial), and maybe marijuana, acrylamide in crispy carbs such as French fries, betel nuts, caramel coloring, red dye No. 3, chlorhexidine found in certain mouthwashes, industrial chemical pollutants (specifically cadmium) fungal toxins sometimes found in conventional apple juice, kimchi, and yerba mate.
Dr. Greger covers cancer in his full-length presentations:
Topic summary contributed by Katie.