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Lecture Presentation Outline
I.
What Is Cancer?
 Instructor Resources: Unit 22 Nutrition Scoreboard transparency master; Unit 22 PowerPoint
presentation on Multimedia Manager
A. Cancer, second leading cause of death in the U.S., is a group of conditions that result from the
uncontrolled growth of abnormal cells
 Instructor Resources: transparency #11: Top 10 Causes of Death in the U.S. (2001)
B. Cells can begin to grow in any tissue, but lungs, colon, prostate, and breasts are the most
common sites for cancer development
C. Some forms of cancer are highly curable
II. Development of Cancer
A. Cancer develops by processes not yet fully understood
1. Adding to complexity is fact that cancer development is not linear - cancer can progress two
steps forward and then take a step or two back
2. Cancer begins when something goes wrong that modifies cell division
a. Every minute, 10 million cells in the body divide
b. Usually they divide the right way
B. Phases
 Instructor Resources: transparency #61: Cancer Development
1.
2.
3.
At initiation something alters DNA in certain cells
During promotion phase, cancer cells with altered DNA divide, producing large numbers of
abnormal cells
a. This phase takes place over 10 to 30 years
Unless corrected by some means, abnormal cells continue to divide, leading to progression
phase of cancer development
a. Body loses control over abnormal cells, numbers increase rapidly
b. Eventually cells become so numerous they erode normal functions where they are
growing
c. Now abnormal cells can migrate to other tissues and cause DNA damage and abnormal
cell development in these tissues, too
III. What Causes Cancer?
 Instructor Resources: Activity 22-3: Cancer Knowledge and Risk Assessment
A. 80-90% of all cancers are related to environmental factors
1. Smoking
2. Exposure to asbestos
B.
C.
D.
E.
F.
3. Chemical pollutants
4. Radiation
5. Diet is a major environmental factor and may account for 40% of cancer risk
Environmental Factors
1. Rates of breast cancer are low in rural Asia
2. When rural Asians immigrate to U.S., rates of breast cancer becomes same or higher than U.S.
rate by third generation
3. Rates of prostate cancer similarly increase as people move from countries with low-to-high
rates
Dietary Factors
1. Westernization of dietary intake and lifestyle increases the risk of many types of cancer
a. Rates of breast cancer in Japanese and Eskimo women increase substantially as
Westernized diets and lifestyles have become adopted
Genetic Factors
1. Some people have tendency toward cancer
2. They develop cancer if regularly exposed to certain substances in the diet or environment
3. Genetic factors account for 42% of risk for prostate cancer, 5 to 27% of risk for breast cancer,
and 36% of risk for pancreas cancer
4. Endometrial cancer (cancer of the lining of the uterus), oral, thyroid, and bone cancer do not
appear to be related to inherited factors
Cancer Preventable
1. Cancer is a largely preventable disease
2. Increasing rates of new cases of cancer took a turn for the better after 1992 and correspond to
declines in rates of tobacco use
3. Other improvements in lifestyles and diets will lead to further declines in cancer rates
Lifestyle Risks of Cancer
1. Cancer-promoting diets are low in vegetables and fruits
2. High saturated fat, regular intake of charred and nitrate-cured meats, and excessive alcohol
are associated with cancer
3. Low intakes of whole grains, dried beans, nuts, and seeds increase cancer risk
4. Other risk factors include smoking, physical inactivity, and excess body fat
IV. Foods and Cancer
 Instructor Resources: ABC video clip on Multimedia Manager: Colon Cancer and Diet (2:55)
A. Foods may also help
1. Frequent consumption of certain foods are strongly related to certain cancers
2. Consumption of tomato products related to decreased risk of prostate cancer
3. Green tea contributes to breast cancer reduction
4. Diets and lifestyles that prevent cancer are represented by characteristics, not hard rules
about specific foods, dietary restrictions, or types of physical activities
B. Dietary Risk Factors
 Instructor Resources: Activity 22-2: Grocery Store Observation
1.
Foods contain vitamins and minerals, fiber and phytochemicals that protect the body against
cancer
a.
b.
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
2. Foods provide protection against cancer, but extracted phytochemical supplements do not
3. Diets that prevent cancer are based on regular intake of an array of foods
C. Fruits and Vegetables
 Instructor Resources: CNN Today Nutrition Vol. 2: Vitamins and Cancer (2:05)
1.
People who consume plenty of vegetables and fruits (5 or more servings daily) have a lower
risk of developing a number of types of cancer than people who eat few
2. Cancer continues to decline as intake of fruits and vegetables increases
3. Some experts advise people to consume 5 to 9 servings daily
4. It is not clear why fruits and vegetables have this effect
D. Antioxidants
 Instructor Resources: transparency #62: Antioxidants in Colorful Foods; Activity 22-1: Antioxidants
and Non-Nutrients
1.
2.
Vitamin C, beta-carotene, vitamin E, and selenium are 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
3. Phytochemicals in vegetables and fruits may participate in cancer prevention by protecting
cells from damage due to oxidation and by inhibiting the multiplication of abnormal cells
4. How Much?
a. 3 cruciferous (broccoli, cabbage, cauliflower, and brussel sprouts) vegetable servings per
week reduce the risk of lung, bladder, and prostate cancer
b. Phytochemicals act as antioxidants
c. Phytochemicals participating in cancer prevention are brightly colored
d. This feature has lead to the advice to select and consume colorful vegetables and fruits
E. Whole Grains and Cancer
 Instructor Resources: CNN Today Nutrition Vol. 2: Heart Cereal (2:01)
1.
F.
Whole grains have vitamins, minerals, fiber, unsaturated fatty acids, and phytochemicals that
work in cancer prevention
2. Effect on cancer risk is related to the combined action of these substances
3. Isolation of a single substance destroys its ability to function in cancer prevention
4. Americans are advised to include three or more whole grain products in their daily diet
Saturated Fat and Cancer
1. High saturated fats from meats and dairy products increase risk of cancer
2. Recommendations for diet and cancer prevention include plant sources of protein because
plants also provide unsaturated fats
3. Dried beans, soy products, nuts, and seeds provide vitamins, minerals, fiber, and
phytochemicals that help ward-off cancer progression
4. Fish are a good source of protein and unsaturated fats
a. Regular consumption of fish is related to lower rates of cancer
G. Nitrate-Preserved Meats
1. Cancer of stomach and liver related to regular consumption of hot dogs, lunch meats, bacon,
pickled eggs, and vegetables preserved with nitrates
a. 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
common
H. Grilled and Charred Meats
1. Substances in beef, chicken, fish, and other meats become cancer promoting if heated to high
temperatures
2. High temperatures can be reached by broiling and grilling food
3. Cancer-promoting substances in charred portions of meat and fatty coating that forms on
meat when fat drips into heat source and smokes
V. 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 can be transferred to dietary intake by
proper selection of foods
A. Substance Use and Cancer
1. Consumption of excessive alcoholic beverages is linked to cancer of the breast, mouth, throat,
and liver
2. Risk of developing cancers of mouth and throat increase for people who smoke cigarettes or
chew tobacco
B. Body Fat and Cancer
1. Central obesity increases the risk of cancer at several sites
2. Central fat alters metabolism of hormones such as estrogen, testosterone, and insulin to
promote growth of abnormal cells
3. Calorie-reduced diets combined with at least 30 minutes of moderate or vigorous activity 5 or
more days a week are recommended for cancer prevention
C. Bogus Cancer Treatments
1. Cancer cures like macrobiotic diets, hydrogen peroxide cocktails, laetrile tablets, vitamin,
mineral, herbal, and phytochemical supplements, and animal glands are not good treatments
for cancer
2. These remedies have been promoted since the early 1900s
3. They do not work, but they offer desperate cancer patients a ray of hope
4. These are not a substitute for conventional cancer treatment
D. Eating to Beat the Odds
1. Two thirds of people in U.S. do not develop cancer
2. Improve your odds by
a. Not smoking or drinking
b. Consuming five or more fruits and vegetables daily
c. Sticking to a low-saturated-fat diet
d. Being physically active
e. Maintaining a normal level of body fat
3. No guarantees, but you help prevent cancer by a good diet and a healthy lifestyle