I am teaching a class on Cancer Prevention this month, and in preparation for that class, I have been reviewing the Dietary Recommendations of the American Institute for Cancer Research (AICR), the Angiogenesis Foundation’s Eat to Beat Cancer webpage, and I took a continuing education class on Nutrition and Cancer through the Arizona Center for Integrative Medicine (ACIM). This post (and my upcoming free classes) are a synthesis of what I have learned from these 3 evidence-based resources.
Cancer is the number one cause of death worldwide (#2 cause of death in the US – behind heart disease) and there is substantial interest in prevention and treatment of cancer with diet. Unfortunately, many people wait until after they are diagnosed with cancer, to turn to the internet for information on how nutrition can help them through their new diagnosis, rather than making those dietary changes with hopes of preventing “the Big C.”
There is much more evidence & research exploring how better nutrition can help prevent cancer than there is for treating cancer with diet, however the basic principles of a cancer-prevention diet should also be followed by those living with cancer. According to the American Institute for Cancer Research:
“Though this is a relatively new area of investigation, so far the science suggests that the same simple guidelines that help prevent cancer also help guard against its return.”
Be as Lean as Possible:
One of the biggest risk factors for cancer is being overweight/obese. This could simply be a lack of exercise, or a nutrient poor diet (both are risk factors), but it is also related to carrying around excess body fat, which secretes hormones that lead to chronic inflammation, and may help promote growth of certain forms of cancer. So it is important to “be as lean as possible” to reduce your risk for cancer. Exercise reduces the risk significantly for breast, endometrial, and colon cancers.
For the visual learners out there, the Center for Disease Control (CDC) produces state by state maps showing states with the highest rates of cancer and the highest rates of obesity and there are clearly correlations between these 2 health indicators in the US.
What to eat?
The next step is to evaluate the proportion of foods on your plate at each meal. How much of your plate contains plant foods? How much contains animal foods? Aim for meals made up with (at least) 2/3 of the plate plant foods: vegetables, fruits, whole grains, beans, nuts, seeds. Animal proteins should make up less than 1/3 of your plate, according to the AICR’s Model Plate for a Cancer Preventive Diet. So, if you are having a steak for dinner, don’t serve everyone an 8oz sirloin; instead cook one steak, and slice it up into thin strips for everyone to share…maybe add that sliced steak to a stir fry with some broccoli and carrots, and serve it over whole grain rice.
Are some vegetables better than others?
YES! Of course, all vegetables provide a wide range of essential and non-essential nutrients, and are low in calories – so they help maintain a healthy weight, and also provide nutrients that support our body’s defense systems. But when it comes to fighting cancer, there is evidence that kale is better than lettuce, and carrots are better than potatoes….so your choices certainly do matter. Here are a few specific Cancer Fighting foods….and just for fun, I will focus on foods that start with the Letter C.
- Carrots (and Carotenoids): Did you know that if you ate nothing but carrots your skin would turn orange? That is because the beta-carotene found in carrots (and other orange, yellow, red, green veggies) gets stored in our skin, where (in addition to changing our skin tones), it also helps prevent the carcinogenic damage caused by UV light to our skin. Lycopene is another carotenoids found in red foods (like tomatoes and watermelon) that can be stored in a male’s testes, where this carotenoid helps prevent prostate cancer.
- Tip: carotenoids are fat soluble, meaning that you need to consume with some fats: think ranch dressing on your raw carrot sticks, or olive oil on your caprese salad. Concentrated tomato products like ketchup and tomato sauce are the highest sources of lycopene.
- Cruciferous Veggies: Cabbage, broccoli, cauliflower, kale, collards (and many others) make up this “family” of vegetables that have strong, pungent tastes as well as strong, cancer-fighting properties that come in the form of glucosinolates and isothiocyantes. It’s interesting that these veggies are found in traditional diets around the world: bok choy in Asian cooking, kohlrabi in Eastern European cuisine, or collard greens in the American South.
- Tip: let these veggies aerate for a few minutes after chopping and before cooking to allow an enzymatic reaction that maximizes these powerful phyto-nutrients. Try to eat a ½ cup of these veggies every other day.
- Cherries: Both sweet and tart cherries provide anthocyanins – antioxidants that provide the color and cancer fighting powers in these seasonal fruits. Tart cherries have much higher levels than sweet cherries or Rainiers.
- Tip: When fresh cherries are not in season, look for frozen cherries for smoothies and baking, dried cherries for snacking and salads, and cherry juice for your smoothies.
- Cranberries: Similar to cherries, cranberries get their color, flavor, and cancer fighting reputation from antioxidants, including anthocyanins and ursolic acid found in these tart fruits that also benefit our urinary tracts, teeth, and heart – in addition to helping fight the Big C.
- Cinnamon: Common spices like cinnamon are some of the most interesting and powerful foods that provide a wide range of anti-cancer properties. Cinnamon has anticancer properties in both lab and animal studies. Cinnamon also helps prevent diabetes, reduces inflammation, boosts heart health, and even boosts brain activity and function. Just ½ tsp per day can provide a wide range of health benefits.
- Coffee and Cocoa: For decades, the World Health Organization cautioned us that coffee was “probably carcinogenic” because of research showing higher levels of bladder cancer in frequent coffee drinkers. We now know that this was not caused by the coffee, it was simply because coffee and cigarettes are very frequently consumed together….newer research found that if you drink coffee but don’t smoke, the coffee is actually protective against a number of cancers, leading the WHO to make “a rare reversal” in 2016 and acknowledge that coffee can prevent not promote cancer.
- Unsweetened cocoa powder is one of the highest sources of antioxidants, and many of those antioxidants help stop angiogenesis, a process that helps cancer cells proliferate.
- Tip: avoid scorching hot coffee, tea, and cocoa because frequent consumption of HOT beverages is linked to esophageal cancer, due to the damage to the throat from excessively hot beverages.
- Catechins (tea) Green tea may not start with the letter C….but tea is full of Catechins, including Epigallocatechin Gallate (EGCG) – the “Most Effective Cancer Chemopreventive Polyphenol in Green Tea” …. A 1997 study, cited on the amazingly informative NutritionFacts.org reported that “green tea appears to be potentially an ideal agent for chemoprevention….” For several reasons including: a) little adverse effects b) high efficacy; c) effective at achievable doses; d) easy to consume orally; e) known mechanism of action; f) low cost; g) history of use
- Curcumin (turmeric) Spices and herbs contain phytonutrients that are not found in any other foods, and we are now learning that many of these unique phytonutrients found in colorful spices like turmeric might be some of the most promising tools in our cancer-prevention-diet plan.
- According to the AICR: “Turmeric stands as one of the most extensively studied spices, with over 1,700 lab studies published over the last few decades…..Turmeric gets its yellow pigment from curcumin, a polyphenol that is the primary phytochemical scientists are investigating for its anticancer potential. In the lab, curcumin modulates cell signaling pathways, suppresses tumor cell proliferation and induces apoptosis of cancer cells. There is evidence that curcumin can suppress inflammation and inhibit tumor survival, initiation, promotion, invasion and metastasis. The findings from lab studies have led to clinical trials in humans, which are generally small but have generated promising findings”
- It is encouraging to see that the “Therapeutic applications of curcumin for patients with pancreatic cancer” is being researched, now that several studies have shown it to be a safe and effective adjunct therapy, in combination with chemotherapy.
- Chick peas: so far all of these foods on this list provide a wide range of vitamins, minerals, fiber, antioxidants …. But not too much protein. Beans and Whole grains provide protein, slow-digesting carbohydrates, as well as providing cancer protection in the form of antioxidants. Tip: canned beans are convenient, but look for BPA-free cans to avoid this controversial packaging liner.
We are learning more and more about how specific foods protect us from Cancer. The research to date is more supportive of foods, rather than supplements when it comes to preventing the Big C. Researchers are seeing some encouraging results when using supplements of curcumin (turmeric) and catechins (green tea), but for the general public – the best recommendations are to focus our attention on foods rather than supplements for a variety of reasons.
Foods contain a range of phytochemicals that work synergistically together in the fight against cancer, so we benefit more when consuming these nutrients from whole foods rather than taking isolated nutrients in pills.
I focused this post (and my upcoming community nutrition classes) on foods that start with the letter C …but of course there are plenty of other cancer fighting foods that start with other letters – including Apples, Berries, Dark green leafy veggies, Escarole, Fennel, Garlic…..I hope that this lesson on the ABCs of cancer prevention has been useful; See below for links to more information on how your food choices can help you Prevent the Big C.
“I have heard there are troubles of more than one kind, Some come from ahead and some come from behind, But I’ve bought a big bat, I’m all ready you see, Now my troubles are going to have troubles with me!”