cancer, diet & phytochemicals. causes of death in us, 2010 in 2010, a total of 2,468,435 deaths...
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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.
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
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
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
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
Unless corrected by some means, abnormal cells continue to divide, leading to progression phase of cancer development
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
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
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
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
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
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
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
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
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.
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
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.
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
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
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.
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
FOCUS: Phytochemicals Diets containing
vegetables, fruits, whole grains, all rich in phytochemicals
strongly associated with low rates of
chronic heart disease and cancer
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
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
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
Carotenoids 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
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
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
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
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
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
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
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
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
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
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
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