Tips for beating cancer should always include dietary components, but all too often, this part of cancer treatment is ignored.
We turned to William Li, MD, world-renowned doctor and author of the New York Times bestseller Eat to Beat Disease: The New Science of How Your Body Can Heal Itself to learn more about his thoughts on using food to activate our bodies’ innate healing abilities.
Q: Could you share a list of the top surprising foods linked to cancer?
A: There’s a laundry list of foods that increase risk for cancer, and these include some disturbingly common foods such as processed meat, which is classified as a carcinogen by the World Health Organization, and grilled meats.
Grilling meat produces polycyclic aromatic hydrocarbons (PAH). These are carcinogens that form when oils from the meat drip into the flame and smoke. The rising smoke deposits the carcinogens right on the meat. High grilling temperatures also convert amino acids and proteins in meat into toxic heterocyclic amines (HCA).
And if you don’t carefully clean the grill surface and leave the black char, the next time you put food on the grill, you are coating it with carcinogens.
Q: We often hear that the body “wants to be well” and has an incredible capacity to heal itself. Why, do you think, don’t more oncologists talk about food choices when a person is diagnosed with cancer?
A: The body is hardwired with health defense systems that work to help us resist diseases, including cancer, from the time we are born to our last breath. These health defenses, which I describe in my book Eat to Beat Disease, are:
- Our regenerative system
- Our microbiome
- DNA protection
- Our immune system
These systems help our body heal itself. However, when they are weakened or damaged, cancer can develop.
Oncologists aren’t trained to look at health defenses — they are trained to diagnose and treat the cancers that have evaded them. The treatments involve surgery, drugs and radiation — food is not part of their traditional toolbox. And all doctors have little to no education or training when it comes to nutrition.
All of this is changing because oncologists are beginning to recognize the impact of food in cancer treatment.
For example, a study by oncologists of 826 patients with Stage III colon cancer undergoing treatment found that those who ate two servings of tree nuts each week had a 57 percent improvement in survival.
Another oncology study of 249 patients with various cancers who were being treated with immunotherapies found that those who did not respond were lacking a healthy bacterium in the gut microbiome called Akkermansia. The only way to grow Akkermansia is by consuming foods like pomegranate, cranberries and mangoes. This is emerging evidence that food can collaborate with medicine to improve cancer treatment. Oncologists are starting to pay attention.
Q: If someone is newly diagnosed with cancer, what are the most important foods to start working into the diet right away?
A: Everyone is different, and it’s important to individualize diet based on a person’s needs. For example, someone with diabetes tolerates foods differently from someone with celiac disease. But, there are some general principles for using food as medicine, especially when it comes to cancer.
We know cancers grow blood vessels to feed themselves, so it’s important to eat foods that can starve cancer by cutting off these bad blood vessels. These are called antiangiogenic foods, which include: soy, tomatoes, green tea, oily fish, berries and brassica vegetables.
We also know that cancers are especially dangerous because they contain cancer stem cells, which can keep cancers coming back after treatment. New research shows that cancer stem cell-killing foods exist, including purple potatoes, green tea, coffee and walnuts.
We know a strong immune system can help wipe out cancer cells. Immune-boosting foods include: broccoli sprouts, blueberries and chili peppers.
Eating prebiotic foods that contain fiber, like mushrooms and beans, can feed healthy gut bacteria, which helps lower inflammation and improve immunity. Other microbiome-boosting foods include fermented foods like kimchi, sauerkraut and yogurt.
Knowing your health defenses, and which foods boost them, is key for using diet to fight cancer. But remember, food is not a cure, so diet is an important part of the toolbox along with modern treatments, like immunotherapy or antiangiogenic therapy.
Q: Is there anything else you’d like to add?
A: There are some foods that people should really think twice about consuming, because they disrupt the health defenses that help you avoid cancer. These are: processed meat, sugar sweetened beverages, artificial sweeteners, and ultra-processed foods.
These foods are everywhere, and part of the typical American diet, but consuming them regularly should be considered a risk. Your health defenses can be boosted or lowered by different foods. Choose the ones that boost your health.
William W. Li, MD, is an internationally renowned physician, scientist and author of the New York Times bestseller Eat to Beat Disease: The New Science of How Your Body Can Heal Itself.
His groundbreaking work has led to the development of more than 30 new medical treatments and impacts care for more than 70 diseases including cancer, diabetes, blindness, heart disease and obesity. His TED Talk — Can We Eat to Starve Cancer — has garnered more than 11 million views.
Dr. Li has appeared on Good Morning America, CNN, CNBC and the Dr. Oz Show, and he has been featured in USA Today, Time Magazine, The Atlantic and O Magazine. He is president and medical director of the Angiogenesis Foundation. More information can be found at: www.drwilliamli.com and on social media @drwilliamli