“I can’t change my genes……” is the excuse people often make for their lifestyle habits. What if science told you that YOU CAN protect and modify your genes' activities!? Because science says you can! The foods you eat, beverages you drink, and the lifestyle you live can either turn cancer cells on or off!! Unlike other diseases, cancer is a silent disease. It can take almost 10 years from the exposure to a cancer-causing event until cancer is actually detected in the body. Cancer is the 2nd most prevalent cause of death for adults in the United States--- 577, 190 Americans die each year from cancer (1). Genes do increase the risk of an individual developing cancer. However, the American Cancer Society reports that only 5% of cancers are “strongly hereditary”, meaning that your genes have a greater impact on development of cancer than environment (1). For most cancer production, however, lifestyle choices have a greater impact on the development of cancer! Lack of physical activity, overweight/obesity, and poor diet contribute to 1/3 of all cancer deaths, while exposure to tobacco contributes to 1/3 of cancer deaths (2). Cut the smoking habit, and you will do yourself and your neighbors a huge favor!!! We must also teach children about PREVENTION of cancer at a young age… exposing children to healthy lifestyle choices NOW because behaviors established in childhood track into adulthood (2), making behavior patterns more difficult to reverse or modify.
Guidelines for the American Cancer Society on Cancer Prevention recommend the following (1-2):
1. Maintain a healthy weight: 14-20% of all cancer deaths are attributed to overweight and obesity. Cancer risk increases with weight status due to hormone production and inflammation that are known to increase with unhealthy weight status.
2. Increase physical activity and REDUCE time spent sitting: Activity helps maintenance of a healthy weight and reduces risk of all other chronic diseases. Aim for 300 minutes of moderate-intensity (walking, light dancing, yoga, golfing) or 150 minutes of vigorous activity (running, skating, aerobic activity, weight training) each week for optimal protection against cancer!
3. Eat a whole, plant-based diet: the American Cancer Society states: “Consume a healthy diet, with an emphasis on plant foods.” Eat a nutrient-dense diet, meaning foods that are packed with vitamins, minerals, phytochemicals, and fiber (e.g. fruits, vegetables, beans, nuts, whole grains….) rather than foods that are high in added sugars, highly processed, and fried (e.g. pop, candy, chips, store-bought cookies, ice cream, traditional American french fries, refined flours and grains….). Don't rely on supplements to give you antioxidants, phytonutrients, and fiber—supplements don’t have the same protection as eating the whole plant-based foods (2).
4. EAT LESS MEAT (and animal products). “Current evidence supports approximately a 15-20% increased risk of cancers of the colon and rectum per 100 grams of red meat or 50 grams of processed meat consumed per day, while the evidence for some other cancers (e.g. esophagus, stomach, lung, pancreases, breast, prostate, stomach, endometrium, renal, and ovarian) is considered limited and suggestive”(2, pg 40). Further, the American Cancer Society states… “… there is little evidence to suggest that red meat is beneficial for chronic disease risk, and substantial evidence that it is likely to have harmful effects on all-cause mortality and cancer risk.” (2, pg 41). There are several reasons why animal protein increases cancer risk. Sorry bacon lovers! High-heat cooking, pan-frying, and grilling are known to produce carcinogens and mutagens (that promote cancer production in the body). Nitrates and nitrites in processed meats are also known carcinogens. Fish, though often promoted for it’s omega-3 fatty acids, also contains a high level of environmental pollutants (e.g. mercury, PCBs, dioxins), which are harmful at higher exposures. If you eat seafood, it's recommended to vary the kind of seafood eaten to avoid high exposures to any one pollutant (2). Additionally, the American Cancer Society states that they “do not make specific recommendations regarding calcium and dairy food intake for overall cancer prevention.” (2, pg. 50).
**Research for dairy and other animal-sourced foods tend to be mixed-- meaning some animal-sourced foods don't cause certain cancers, but promote others (e.g. dairy has been linked with prostate cancer, but not colon cancer). The American Cancer Society makes conservative recommendations about limiting animal-sourced foods. If you choose to eat animal products, consume less of them and opt for organic products (not processed, conventional, or factory farmed). However, keep in mind that there is a growing body of evidence that suggests animal-sourced foods play apart in cancer production (see references 6 and the Tedtalks below for more info). We know that plant-based foods can provide all essential nutrients (expect vitamin B12 which we recommend for all people over the age of 50!) and plants offer cancer protection with all their phytonutrients and fiber! Research from quality longitudinal studies show that vegans and vegetarians have lower rates of cancers than non-vegetarians (7).
5. Limit alcohol. Either drink within LIMITS (2 servings of alcohol for men, 1 serving of alcohol for women, per day**) or don’t drink at all. There is a fine line where alcohol no longer has beneficial, health-promoting properties. Overconsumption of alcohol increases risk of cancers of the mouth, esophagus, breast, liver, and colon. The American Cancer Society states, “Compared with non-drinkers, there is a 10% to 12% higher increase of female breast cancer associated with each drink per day.”….. “Consumption of 3 drinks per day is associated with a 1.4-fold higher risk of colorectal cancer.” (2, pg. 43). It is believed that the acetaldehyde from alcohol metabolism causes damage to the DNA in normal cells (2, pg. 43).
William Li, ask the question in his Tedtalk, “Can we eat to starve cancer?”
Nutrition, genes, and cancer
Though it is exciting news to hear that your diet and lifestyle can greatly reduce your risk of cancer, The American Cancer Society says that no lifestyle offers COMPLETE protection against cancer. We live in a world full of toxic chemicals..... BUT don’t let that stop you, however, from limiting your exposure to chemicals in your foods, in your drinks, in your cleaning products, and in your beauty products! Living in prevention is beautiful! Physical activity and eating a diet rich in whole, plant-based foods will decrease your risk of other chronic disease (like cardiovascular disease, diabetes…) and help you live to your optimal potential every single day! Make each second of your life count!
When in doubt, just do like the centenarians!
References and resources for more specifics on nutrition and cancer:
1. American Cancer Society (2012). Cancer Facts and Figures 2012. Retrieved: here.
2. Kushi, L. et al. (2012). American cancer of society guidelines on nutrition and physical activity for cancer prevention; reducing the risk of cancer with healthy food choices and physical activity. Cancer Journal for Clinicians, 62: 30-67. Retrieved: here.
3. ** A drink is equal to 12 oz of beer, 5 oz of wine, or 1.5 oz of spirits/hard liquor. Read more on Alcohol from Harvard: Alcohol: Balancing Risks and Benefits
4. Phytates from plant-foods are often scrutinized by some health professionals for being an “anti-nutrient”, however, phytates are considered to be a phytochemical and help protect against cancer. A guide to phytochemicals from the American Institute for Cancer Research can be found: here. More on phytochemicals from Stanford: here. Cancer Society on Phytochemicals: here.
5. Soy is one of those foods that the general population believes to causes cancer. However, a body of evidence suggests otherwise. If you consume soy, opt for non-GMO, organic soy products (e.g. edamame, whole soy beans, tofu, miso, tempeh) and don’t eat more than 3-5 servings per day. Here are some good readings: How much soy is too much?, American Cancer Society on Soy: here, Jack Norris, RD “Soy: What’s the Harm?” , Ginny Messina, R.D. “Soy Isoflavones and Estrogen”, Academy of Nutrition and Dietetics on Soy Safety, More on Soy from the American Institute for Cancer Research: here
6. Animal-sourced food and cancer: More on Cancer from Nutrition Facts, TMAO from animal products and increased chronic diseases, Animal Protein and the Cancer Promoter IGF-1 , Does too much iron from animal sources increase risk of cancer?, Harvard on dairy: Calcium Full Story, Animal foods and Cancer from The World Cancer Resource Center. NIH: Risk in Red Meat?, NIH: Pan-Fried Red Meat Increases Risk for Prostate Cancer
7. Limo Linda University research study results on cancer and diet: here , "Why vegan women have fewer female cancers?", "Vegan Men: more testosterone, but less cancer", "How Plant-Based to Lower IGF-1?"