Lecture 22 Diet and Cancer Back to Treating Melanoma First cancer fighting virus approved T VEC Is the type of immunotherapy stimulates activity of immune system against cancer cells Kills cancer cells onco cancer lyctic destroy Highly engineered herpes virus no longer causes herpes Approved for melanoma Must be injected directly into tumor remember our immune system generally wants to get these guys One of many oncolytic viruses in development Guidelines for Cancer Prevention 1 Be as lean as possible without becoming underweight 2 Be physically active for at least 30 minutes every day 3 Avoid sugary drinks Limit consumption of energy dense foods 4 Eat more of a variety of vegetables fruits whole grains and legumes such as beans 5 Limit consumption of red meats such as beef pork and lamb and avoid processed meats If consumed at all limit alcoholic drinks to 2 for men and 1 for women a day 6 7 Limit consumption of salty foods and foods processed with salt sodium 8 Don t use supplements to protect against cancer 9 It is best for mothers to breastfeed exclusively for up to 6 months and then add 10 After treatment cancer survivors should follow the recommendations for cancer other liquids and foods prevention A Healthy Diet Reduces Cancer Risk The American Cancer Society Publishes a list of Recommendations for Healthy Eating that Include Eat 5 or more servings of fruits and vegetables a day Eat a fruit or vegetable at every meal and for snacks Choose whole grain rice pasta bread and cereals instead of processed grains Limit your intake of red meats and foods high in animal fat Diet and Obesity Attributed to 31 of Cancer Deaths Tobacco and smoking 31 Diet and Obesity 31 Been Awake the Last Three Days Bacon and hot dogs is the highest risk Red meat is the second highest Lifetime risk of colon cancer is 5 have a hot dog every day risk is raised to 6 There are benefits to eating red meat as well NOTE The IARC International Agency for Research on Cancer for WHO is in the business of identifying hazards but not assessing risks So is tobacco a carcinogen YES Are they associated with the same risk of cancer NO Is processed meat a carcinogen YES Tobacco vs Meat What s the Risk The evidence that processed meat causes cancer is as strong as the evidence for tobacco but the risk from tobacco is much higher Cancers caused by tobacco 86 of lung cancers 19 of all cancers Cancer caused by processed and red meat 21 of bowel cancers 3 of all Meat Consumption and Colon Cancer The U S is high on the graph in colon cancer cases and amount of meat cancers consumed Red Meat Probable cancer causing agent Red meat mammals pork sheep beef goat bison Limited correlative evidence and strong mechanistic evidence More blood in tissue vs poultry and fish related to carcinogenic activity Rare is good cooking bad especially with high heat Group 1 causes cancer Processed meats have been given group 1 classification includes bacon sausages and hot dogs salami Group 2 Probably causes cancer Red meats have been given group 2A classification Group 2B Possibly causes cancer Group 3 Not classifiable as a cause of cancer Probably not a cause of cancer Why is Processed Meat Carcinogenic Meat that is not fresh and has been modified from naturally occurring state So salt preserved pickled cured smoked fermented or other processes to enhance flavor or improve preservation IARC Bacon corned beef ham sausages hot dogs jerky canned meat lunchables beenie weenies Nitrates salt sugars saltpeter eventually metabolize to carcinogens called N nitroso compounds NOCs or nitrosamines NOC s bind to DNA lead to changes in nucleotide or general DNA damage that is conserved during replication Polycyclic Aromatic Hydrocarbons PAH alter DNA interact with estrogen receptors and can indirectly alter cell signaling to increase cellular growth and replication How Much Meat Do You Eat a Day WHO report states 50g processed meat day increases risk of colorectal cancer to 18 up from 6 lifetime risk 100g of red meat is needed to do the same 285g total eaten 70g recommended Obesity and Cancer 90 of Americans unaware of link between obesity and cancer American Society of Clinical Oncology predicts obesity to surpass tobacco leading cause of cancer by 2017 Obesity Trends Among U S Adults Rates have increased from 1990 to 2009 Preventable Cause of Death Smoking 18 Obesity 15 World Obesity Prevalence Not just the U S with high rates Body Mass Index and Cancer Large trend between the two Body mass index weight in lbs height in inches 2 703 Obesity is Leading Cause of Cancer in Non SmokerS Obesity Cancer Links Fat tissue produces excess estrogen high levels of estrogen associated with breast and other scans Increased levels of insulin and insulin like growth factor 1 IGF 1 in blood may promote tumor development e g prostate Fat cells produce hormones that stimulate or inhibit cell growth Leptin is abundant in obese people it is likely linked to cell proliferation Fat cells have direct and indirect effects on tumor growth regulators Obese people often have chronic low level or subacute inflammation which has been associated with increased cancer isk Energy Dense Foods McDonalds Subway KFC Sonic Burger King Pizza Hut Wendy s Starbucks Taco Bell Dunkin Donuts Food Calories and Cancer Risk Most chemicals encountered daily though ingestion from foods Cancer risk is related to both foods that increase or decrease risks Diets rich in saturated fats especially red meats have been linked to several types of cancers colon breast prostate Apparent linkage is because fats have a higher calorie content that other nutrients Fat and Total Calories Calorie amount of energy or heat it takes to raise the temperature of 1 gram of water by 1 degree Celsius 1 8 degrees Fahrenheit Foods are a compilation of carbohydrates fats and proteins 1 gram of Fat 9 calories 1 gram of Carbohydrate 4 calories 1 gram of Protein 4 calories It s not the calories you eat it s the calories you don t burn off that increase cancer risk 2g fat 18 4g protein 16 32 g carbohydrates 128 Some Phytochemicals that Reduce Cancer Risk and Their Sources Green tea Brocoli Soybeans Grapes Garlic Antioxidants Vitamin A B6 B12 B9 C D E Selenium Calcium Zinc Counteracting Free Radicals with Antioxidants Every time your body undergoes stress from sunburn to scotch you produce renegade molecules called free radicals Producing too many free radicals can damage your cells tissue and organs You can protect your cells
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