A presentation at the American Society for Nutrition’s Scientific Sessions at Experimental Biology 2016 showed that certain dietary habits are associated with increased risk for breast and prostate cancer (April 2-6, 2016; San Diego, CA). Of 3184 adults followed for more than 20 years, 565 were diagnosed with cancer. Those who drank sugary drinks had three times as much prostate cancer as those who took in less. Foods that cause high rises in blood sugar were associated with increased prostate cancer risk. Men who ate processed lunch foods (pizza, deli meats and burgers) four or more times a week had double the risk for prostate cancer. Women who ate vegetables, fruits, whole grains and legumes were 67 percent less likely to develop breast cancer, compared with women who favored refined carbohydrates.
Another study of men who had been diagnosed with prostate cancer showed that eating meat increased risk of death from prostate cancer, while eating polyunsaturated fats in vegetables reduced the risk (annual meeting of the American Association for Cancer Research, April 19, 2016).
Many previous studies have shown that lifestyle factors, such as lack of exercise, excess body fat or diets high in refined carbohydrates or red meat and processed meats, increase risk for cancers of the stomach, colon, biliary tract, pancreas, lung, breast, prostate and endometrium (British Journal of Cancer, Jan 4,2011;104 (1): 6–11 and European Journal of Clinical Nutrition, 2007;61(Suppl 1):S112–S121).
Lifestyle Factors Associated with Increased Risk for Cancer
The following factors have been associated with increased risk for cancer in humans:
• Chronic inflammation
• Lack of exercise
• Various infections
• Certain hormones
• Cumulative lifetime exposure to radiation
• Cumulative lifetime exposure to various carcinogens
The following dietary factors have been associated with increased cancer risk:
• Sugar-added foods
• Sugared drinks
• Red meat and processed meats
• Fried foods and grilled or charred foods, particularly meats and fats
• Lack of plants: fruits, vegetables, beans, whole grains and other seeds
• Eating refined grains instead of whole grains
How Inflammation May Cause Cancer
When a germ gets into your body, your immunity recognizes that the germ cells have proteins on their outer surfaces that are different from your body’s own cells. Your immunity produces cells and proteins that attack and kill these invading germs. However, as soon as the invading germs are gone, your immunity is supposed to slow down and stop producing all the proteins and cells that did the attacking and killing. Inflammation means that your immunity stays active and starts to attack and damage your own cells and the DNA genetic material inside them.
Normal cells undergo apoptosis which means that they live only a certain number of days and then die. However, if your immunity damages your DNA, the cells may be changed so they forget to die and try to live forever, which is cancer. The “immortal” cancer cells overgrow and invade other tissues to destroy them and kill you. For example, breast cancer cells do not kill you as long as they stay in the breast, but the breast cancer cells can become so numerous that they spread to your brain, lungs, bones and other tissues and kill you by destroying these essential tissues.
High Blood Sugar Causes Inflammation
The same cells and chemicals that kill germs also start the healing process, so damage to any tissue in your body turns on your immunity in the same way that infections do and therefore can cause inflammation. When blood sugar levels rise too high, sugar sticks to the outer membranes of all the cells in your body and damages them to turn on your immunity. All the harmful effects of diabetes, such as impotence, dementia, blindness, deafness, heart attacks and cancers, are caused by high blood sugar turning on your immunity, and you don’t have to be diabetic to suffer this damage. A review of the world’s literature shows that non-diabetics with high blood sugar levels suffer a marked increase in breast, colon, liver, stomach, pancreatic and endometrial cancers. (Diabetologia, September 8, 2014). Furthermore, high blood sugar levels cause high insulin levels that also increase cancer risk (JCI May 2013;4(3)). High blood sugar levels can be caused by any of the high-glycemic-load foods, including all sugared drinks, fruit juices, sugar-added foods, foods made from flour, white rice, potatoes and yams (Cancer Epidemiology, Biomarkers & Prevention, March 3, 2016). Other studies show that high blood sugar levels are associated with increased risk for prostate cancer (Horm Cancer, April 2016;7(2):75-83) and breast cancer by causing inflammation through the 12-Lipoxygenase (12-HETE) pathway (Cancer Res, Jan 1, 2016;76(1);24–29).
Overweight Causes Inflammation
Full fat cells also produce the same cells and chemicals that turn on your immunity, which is why obesity is a major cause of inflammation in healthy adults (International Journal of Cardiology, April 14, 2016;215:318-324). Many studies show that obesity causes inflammation by increasing interleukin-6, BP and insulin insensitivity (International Journal of Cardiology, April 14, 2016;215:318-324 and J Clin Endocrinol Metab, Mar 2001;86(3):1154-9). Overweight causes high blood sugar levels; blood sugar levels rise with increases in body weight, BMI and waist circumference (Cardiovasc Diabetol, Feb 6, 2012;11:13). Excess weight also increases risk for metabolic syndrome and diabetes (Nutrition, Metabolism & Cardiovascular Diseases, November 12, 2015). Storing fat in your belly raises markers of inflammation: C–reactive protein, leptin and insulin (Nutr Metab Cardiovasc Dis, February 2016;26(2):114–122) and many different cancers (Cancer Prev Res, March 2013 6; 177). Excess belly fat is directly proportional to the number of sugared drinks a person takes (Circulation, January 11, 2016).
Red Meat Causes Inflammation
A study of more than 500,000 North Americans over age 40 showed that those who consume the equivalent of at least a hamburger a day had a 30 percent greater chance of dying during the 10-year study period, mostly from heart disease and cancer (Arch of Int Med, March 2009). The same study showed that eating fish, chicken or turkey decreased risk of premature death. For each increase of three ounces of red meat per day there was a 16 percent increased risk of death from heart attacks, a 10 percent increased risk from death from cancer and a 12 percent increased risk of death overall (Archives of Internal Medicine, November 12, 2012).
We have known for more than sixty years that red meat is associated with increased risk for inflammation. In 1982, Professor Ajit Varki of UC/San Diego explained a possible mechanism. He discovered a sugar-protein molecule that he called Neu5Gc, which is found in the tissues of every mammal except humans (Proc Nat Acad Sci, Sept 29, 2003). He found that people who eat red meat have antibodies against Neu5Gc from the meat they had eaten, which showed that red meat can turn on a person’s immunity. Varki then got a batch of mice that were genetically engineered to be like humans in not having any Neu5Gc. Feeding large doses of Neu5Gc to these mice that lacked Neu5Gc caused them to make antibodies against Neu5Gc and caused cancers to grow and spread through their bodies (Proc of the National Academy of Sciences, published online December 29, 2014). See my report on How Red Meat May Increase Risk for Cancer. Red meat has also been associated with increased risk for diabetes, heart attacks, and cancers because it raises insulin levels and decreases insulin sensitivity (Diabetes Care, January 2010).
Stanley Hazen of the Cleveland Clinic has shown that red meats contain choline, lecithin and carnitine. Some bacteria in your intestines convert these substances to trimethylamine-N-oxide (TMAO), another source of inflammation that has been associated with increased cancer risk (Nature Medicine, published online April 7, 2013).
Foods Cooked Without Water Cause Inflammation
When you cook without water, sugars can combine with proteins and DNA in food to form Advanced Glycation End products (AGEs) that are pro-inflammatory (Curr Diabetes Rev, May 2008;4(2):92-100). AGEs are known carcinogens. Animal-derived foods that are high in fat and protein form the most AGEs during cooking. Vegetables, fruits, whole grains and milk form few AGEs. The formation of AGEs can be reduced by cooking with water, for shorter durations, at lower temperatures, and by including acidic ingredients such as lemon juice or vinegar (J Am Diet Assoc, 2010 Jun;110(6):911-16).
The same healthful diet that protects you from heart attacks, strokes and diabetes will help to prevent many kinds of cancers. I recommend a diet that is high in anti-inflammatory foods and low in the pro-inflammatory foods.
Examples of Anti-inflammatory Foods
• whole grains
• fatty fish such as salmon, mackerel, tuna, sardines
• coffee and tea
Examples of Pro-inflammatory Foods
• sweetened beverages and sugar-added foods
• foods made with flour and other refined carbohydrates
• red meat
• processed meats
• butter, margarine, shortening, lard
• fried foods