1. Cancer, Diet & Phytochemicals

2. Causes of Death in US, 2010
In 2010, a total of 2,468,435 deaths occurred in the United States. The first two leading causes of death, heart disease (597,689 deaths) and cancer (574,743), accounted for nearly 50% of all deaths..
Heart disease killed almost 300,000 women in 2010.

3. Key Concepts: Cancer Cancer has many causes
Diet is a factor that influences the development of some types of cancer
Lifestyles and diets based on plant foods that include lean meats, fish, and low-fat dairy products regular physical activity, and normal levels of body fat reduce cancer risk
Cancer is largely preventable, but there are no guarantees that an individual will not develop cancer

4. What Is Cancer?
Cancer, second leading cause of death in the U.S., is really some 200 diseases that cause the uncontrolled growth of abnormal cells (NIH director)
Cells can begin to grow in any tissue, but lungs, colon, prostate, and breasts are the most common sites for cancer development
Some forms of cancer are highly curable

5. Estimated Cancer Deaths in the US in 2013
Lung cancer is by far the most common cancer in men (28%), followed by prostate (10%), and colon & rectum (9%). In women, lung (26%), breast (14%), and colon & rectum (9%) are the leading sites of cancer death.
38,280 deaths from breast cancer

6. Development of Cancer
Cancer develops by processes not yet fully understood
Cancer development is not linear - cancer can progress two steps forward and then take a step or two back
Cancer begins when something goes wrong that modifies cell division
Every minute, 10 million cells in the body divide
Usually they divide the right way

7. Phases At initiation something alters DNA in certain cells
During promotion phase, cancer cells with altered DNA divide, producing large numbers of abnormal cells
This phase takes place over 10 to 30 years

8. Unless corrected by some means, abnormal cells continue to divide, leading to progression phase of cancer development

9. Progression Phase
Body loses control over abnormal cells, numbers increase rapidly
Eventually cells become so numerous they erode normal functions where they are growing
Now abnormal cells can migrate (metastasize) to other tissues and cause DNA damage and abnormal cell development in these tissues, too

10. What Causes Cancer?
80-90% of all cancers are related to environmental factors, including
smoking
exposure to asbestos
chemical pollutants
radiation
And diet-- a major environmental factor-- may account for 40% of cancer risk

11. Environmental Factors
Rates of breast cancer are low in rural Asia
When rural Asians immigrate to U.S., rates of breast cancer become same or higher than U.S. rate by third generation
Rates of prostate cancer similarly increase as people move from countries with low-to-high rates

12. Dietary Factors
Westernization of dietary intake and lifestyle increases the risk of many types of cancer
Rates of breast cancer in Japanese and Eskimo women increase substantially as Westernized diets and lifestyles have become adopted

13. Genetic Factors
Some people have genetic susceptibility to certain cancers
They develop cancer if regularly exposed to certain substances in the diet or environment
Genetic factors account for 42% of risk for prostate cancer, 5 to 27% of risk for breast cancer, and 36% of risk for pancreatic cancer

14. Cancer Preventable Cancer is a largely preventable disease
Increasing rates of new cases of lung cancer took a turn for the better after 1992 and correspond to declines in rates of tobacco use for men
Other changes in lifestyles and diets may lead to further declines in cancer rates
… or to increases

15. Cancer-promoting lifestyle
DIET
Red meats and saturated fat
Includes charred and nitrate-cured meats
Excessive alcohol
Other Risk Factors
Smoking
Physical inactivity
Excess body fat

16. Eating to Beat the Odds
Two thirds of people in U.S. do not develop cancer
Improve your odds by
not smoking
Eating a low red-meat and saturated-fat diet
being physically active
drinking in moderation or not at all
consuming plenty of fruits and vegetables daily
maintaining a normal level of body fat
No guarantees, but you help prevent cancer by a good diet and a healthy lifestyle

17. The Latest: Red meat may raise young women’s breast cancer risk
Compared with women who had one serving of red meat a week, those who ate 1.5 servings a day appeared to have a 22% higher risk of breast cancer. additional red meat seemed to increase the risk of breast cancer more. Harvard researchers drew from data on the health of 89,000 women aged 24 to 43, who were followed over a 20-year period. June 2014 British Medical Journal.

18. Illustration The charred and black, oily coating on grilled or broiled meats is the part you shouldn’t eat.
Fig. 22-1, p. 6

19. Grilled and Charred Meats
Substances in beef, chicken, fish, and other meats become cancer promoting if heated to high temperatures
High temperatures can be reached by broiling and grilling food
Cancer-promoting substances are in charred portions of meat and fatty coating that forms on meat when fat drips into heat source and smokes

20. But the problem is not just grilled meat…
One European study tracked 478,000 men and women…. those who ate the most red meat (about 5 ounces a day or more) were a third more likely to develop colon cancer than those who ate the least red meat (less than an ounce a day on average).
Consumption of chicken did not matter, and consumpton of fish reduced risk.

21. Nitrate-Preserved Meats
Cancer of stomach and liver related to regular consumption of hot dogs, lunch meats, bacon, pickled eggs, and vegetables preserved with nitrates
Most cases of cancer from nitrate use in smoked, salted, and pickled foods now occur in China, the former Soviet Union, and Central and South America where such foods are very frequently eaten

22. Recommendations for Protein
Include plant sources of protein because plants also provide unsaturated fats
Dried beans, soy products, nuts, and seeds provide vitamins, minerals, fiber, and more phytochemicals that help ward-off cancer progression
Regular consumption of fish related to lower rates of cancer
Poultry consumption doesn’t increase risk
Limit beef to no more than two 4-oz servings a week

23. Harvard Summary, 2012 Alcohol-Attributable Cancer Deaths
Total cancer deaths 574,743
Alcohol consumption resulted in about 20,000 cancer deaths per year,
3.5% of all US cancer deaths.
About 6,000 from breast cancer
Heart disease killed almost 300,000 women in 2010.

24. Body Fat and Cancer
Central obesity increases the risk of cancer at several sites
Central fat alters metabolism of hormones such as estrogen, testosterone, and insulin to promote growth of abnormal cells

25. FOCUS: Phytochemicals
Diets containing vegetables, fruits,
whole grains, all rich
in phytochemicals strongly associated with low rates of
chronic heart disease and cancer

26. Phytochemicals (aka phytonutrients)
Chemical substances found in plants
Thousands of phytochemicals in plants, and some foods contain hundreds
Not essential, we do not develop a deficiency disease if we consume too
little
Many are antioxidants

27. How Do They Work? Phytochemicals:
-- Act as hormone-inhibitors to prevent initiation of cancer
Antioxidants that prevent and repair damage due to oxidation
block enzymes that promote cancer and other diseases
modify absorption, production, or utilization of cholesterol
decrease formation of blood clots
Some plant pigments are powerful antioxidants
zeaxanthin, anthocyanin and lycopene are strong antioxidants
dark chocolate contains flavonoid antioxidants
some phytochemical antioxidants reduce plaque formation by preventing the oxidation of LDL

28. Antioxidants
May participate in cancer prevention by protecting cells from damage due to oxidation and by inhibiting the multiplication of abnormal cells
Vitamin C, beta-carotene, vitamin E, and selenium are well-known antioxidants in vegetables and fruits
Damage to DNA related to cancer initiation may be caused by exposure to oxidizing substances that disrupt molecules within DNA
Antioxidants are able to repair damaged DNA

29. Carotenoids May protect against prostate cancer
Alpha, Beta, and Gamma carotenes
Lycopenes, lutein, etc., etc.
May protect against prostate cancer
May protect against lung cancer
Tomatoes, tomato sauce
Watermelon, red grapefruit, guava
Red peppers, chili peppers, green peppers
Apricots

30. Color Coding

31. Cruciferous Vegetables
Illustration Some examples of cruciferous vegetables.
Fig. 21-5, p. 5

32. Cruciferous Vegetables
3 cruciferous vegetable servings per week may reduce the risk of lung, bladder, and prostate cancer
Broccoli
Cabbage
Collards, mustard, turnip greens,
Bok choy, brussels sprouts, cauliflower

33. Whole Grains and Cancer
Whole grains have vitamins, minerals, fiber, unsaturated fatty acids, and those phytochemicals that work together in cancer prevention
Effect on cancer risk is related to the combined action of these substances
Advice: include three or more 100% whole grain products daily

34. Phytochemicals
Phytochemicals are heat and light stable, not easily destroyed by cooking or storage
Many are excreted soon after ingestion, so intake of vegetables, legumes, nuts, fruits, and other food sources should be frequent
Cooking vegetables or eating with fat/oil increases absorption of phytochemicals

35. Characteristics
Phytochemicals provide color and flavor and protect plants from insects, microbes, and oxidation due to exposure to sunlight and oxygen
Some are components of a plant’s
energy-making processes
Some act as plant hormones
Many are pigments, like anthocyanins
& function as antioxidants

36. Phytochemicals and Health
Phytochemicals are associated with a reduced risk of developing:
heart disease
certain types of cancer (lung, breast, cervical, esophageal, stomach, and colon cancer)
age-related macular degeneration, cataracts
infectious diseases
Type 2 diabetes
Hypertension, stroke
and other disorders
Evidence supports role for phytochemicals
*Clinical studies to demonstrate cause-and-effect relationships have yet to be completed

37. Phytochemicals in Groups
There is no solid evidence that individual phytochemicals extracted from foods benefit health
Absorption appears to depend on other phytochemicals and nutrients
Most phytochemicals act together synergistically
Optimal combinations are not yet known, so let foods provide them

38. Broccoli: in just 1 cup Over 30 phytochemicals including
Indol-3-carbinol (first cancer-protective phytochemical, discovered in 1970’s)
90% RDA for Vitamin A
200% RDA for Vitamin C
25% daily recommendation for fiber
Fair amounts of niacin, pantothenic acid, folacin, iron, vitamin K, calcium, thiamin & phosphorus

39. Illustration 21.2 A sampling of the chemical substances in two foods.
Fig. 21-2, p. 3

40. Dietary Risk Factors
Foods contain vitamins and minerals, fiber and phytochemicals that protect the body against cancer
Substances in plant foods appear to work synergistically to confer protection
Attempts to prevent cancer by dosing with individual components of plants have not been successful
Foods provide protection against cancer, but extracted phytochemical supplements do not
Diets that prevent cancer are based on regular intake of an array of foods

41. Extracts and Essences
Dehydrated extracts of vegetables high in phytochemicals are available
There is no evidence that these extracts benefit health
“Broccoli Concentrate” contains one phytochemical from the cruciferous family
Only so much will fit into a capsule, so it takes 100’s of pills to get same amount as one serving of broccoli!
Supplements of phytochemicals are unsafe and ineffective

42. Diet and Cancer Guidelines
Dietary patterns and lifestyles to reduce risk of cancer are compatible with dietary recommendations to reduce the risk of heart disease
Considered together, recommendations for cancer prevention and heart disease prevention can be transferred to dietary intake by proper selection of foods

43. Benefits from diets high in plant foods
Vegetables, fruits, whole grains, and other plant foods reduce:
Heart disease Cancer
Type 2 diabetes Infections
Eye disease Premature aging
and a number of other health problems

44. The End
Illustration Consumers have their choice of phytochemicals in pills. The problem is that the supplements have not been shown to benefit health. Phytochemicals taken individually in supplements may actually harm health. They are best consumed in their natural packaging: vegetables, fruits, whole grains, and other plant foods.
Fig. 21-4, p. 5