Eat Right for your Disease - Colorectal Cancer

[Guest guest]

Eat Right for your Disease - Colorectal Cancer JoAnn Guest May 24, 2005

18:04 PDT

 

Eat Right for your Disease - Colorectal Cancer

http://www.whfoods.com/genpage.php?tname=disease & dbid=10

 

Moderator's Note: I am asking that you disregard the information written

in this article regarding the efficacy of using daily doses of aspirin

as a preventive measure against colon cancer. Other than that there is a

substantial amount of beneficial information included here.

JoAnn

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Colorectal cancer refers to cancers that occur in the large intestines.

Food enters the large intestine and travels through the ascending colon,

the transverse colon, the descending colon, the sigmoid colon, the

rectum, and then out of the body. Colorectal cancer can occur anywhere

in the colon or in the rectum and is the third most common form of

cancer in the United States and the third most common cause of cancer

death.

 

Colon cancer develops when cells of the colon are exposed to chemicals

or carcinogens that cause damage to their DNA. This damage leads to

mutations in the cells, which may then reproduce out of control and

spread to other parts of the body, leading to organ damage and

eventually death.

 

There is a great variance worldwide in the incidence of colorectal

cancer with some countries having 10 to 20 times the rate of other

countries. Although genetics may play a role in the disease, many

researchers believe that as much as 90% of these differences can be

explained by dietary factors alone. Fortunately, there are many dietary

habits and nutrients that may help to prevent this devastating and

potentially deadly disease.

 

 

Eat more

Organically grown fruits and vegetables

Extra virgin olive oil

Whole grains for their high fiber

Cold water fish such as alaskan salmon, tuna, herring, mackerel and

halibut for their beneficial omega 3 fatty acids

Onions, garlic and leeks

Brassica vegetables including broccoli, kale, mustard greens

Yogurt

Turmeric

Ginger

Organic Soy foods

Grapefruit

Avoid red meats, omega 6 fatty acids, saturated fats, refined sugar and

alcohol.

 

Description

Dietary Causes

Nutrient Needs

Nutrient Excesses

Recommended Diet

References

Description

What is colorectal cancer?

Introduction

Colorectal cancer, or cancer of the large intestine, is the third most

common form of cancer in the United States and the third most common

cause of death due to cancer. In 1994 alone, there were 150,000 new

cases of colon cancer diagnosed and 56,000 deaths due to colon cancer in

the US. Because colorectal cancer may go undiagnosed for a while and may

spread rapidly, only 60% of people diagnosed with colon cancer survive

for five years past the time of diagnosis. In general, this form of

cancer affects more men than women over the age of 50 years.

 

Colorectal cancer refers to cancers that occur in the large intestines.

Food enters the large intestine and travels through the ascending colon,

the transverse colon, the descending colon, the sigmoid colon, the

rectum, and then out of the body. Colorectal cancer can occur anywhere

in the colon or in the rectum. In general, the risk factors for colon

cancer and rectal cancer are the same.

 

Worldwide, there are very great differences in the incidence of colon

cancer. Some countries may have 10-20 times the rate of other countries.

Unfortunately, when people from an area with a very low rate emigrate to

an area with a higher rate, their incidence increases to match the new

area within one or two generations.

 

Although genetics may play a role in the disease, many researchers

believe that as much as 90% of the differences in rates between areas

can be explained by dietary factors alone. Fortunately, diet is

something that can be changed.

 

Symptoms

Symptoms of colorectal cancer include lower abdominal pain that is

constant or gets increasingly worse, changes in bowel habits, such as a

change to recurrent diarrhea or constipation, blood in the stools,

vomiting, anemia, or weight loss that occurs without a change in eating

habits. Any of these symptoms should prompt someone to seek a more

thorough medical examination.

 

Unfortunately, however, many people with colon cancer don’t have any of

these symptoms until very late in the disease. For this reason, people

are urged to see their doctors every year. Doctors can perform a very

sensitive test for blood in the stools, which is often the first sign of

colon cancer. Doctors can also perform tests called a colonoscopy or a

sigmoidoscopy, which basically examine the inside of the rectum and

colon, looking for actual colon cancer lesions or tumors.

 

Regular doctor visits are the key to early detection and treatment of

colon cancer. If the disease is caught early, it will be much easier to

treat successfully than if it is caught after it has spread to other

locations.

 

The Process

Normally, the cell's DNA organizes the activities of that cell. It's the

blueprint for everything the cell produces and does. Every cell in the

body, with few exceptions, has the same exact DNA as every other cell in

the body. The main difference between types of cells is which portions

of their DNA are currently being used to control the cell’s activities.

 

When cells divide, the cells around them tell them what kind of cell

they are going to be, all based on which parts of their DNA are active.

For example, cells of the colon have different functions than cells of

the liver or kidney. These differences are based on which parts of their

DNA are to be working at the time. This process is called

differentiation and it is very closely and carefully maintained in order

for the body to function properly as a whole.

 

Damage to the DNA of cells happens constantly throughout the day. What

usually occurs is that the damage is either repaired by mechanisms

inside the cell, or the damage weakens the cell, causing it to die

through a process called apoptosis. Cells may also become dysfunctional

and start to produce substances that they wouldn’t normally produce. In

these cases, the cells of the immune system detect the fact that this

cell is now different and destroy it before it does any damage.

 

In some cases, however, these protective mechanisms fail and a cell with

damage to its DNA is able to survive and divide. Most times, this

doesn’t really amount to anything. Eventually the cells die, or the

damage is so slight that the cells can still function properly.

 

If the cell is still being exposed to large amounts of free radicals or

carcinogens, the DNA can become damaged even further. When this occurs,

the cells may start to lose their normal function and start to divide

rapidly. If they are not detected and destroyed by the immune system,

they can continue to divide, producing the beginnings of a tumor.

 

Over time, the cells can continue to accumulate DNA damage and divide

rapidly, leading to a mass in the colon or rectum. The mass may grow

large enough to produce a blockage in the intestines, which can be

life-threatening in and of itself. Or the mass may start to grow

outwards into the area, causing damage to local nerves or blood vessels

and putting pressure on other organs. Or the tumor cells may mutate

until they develop the ability to metastasize (that is, spread to other

areas), such as the liver or bone.

 

Once the cells spread to other areas, they may continue to divide and

grow into masses that are large enough to cause damage and interrupt the

function of these other organs. Death from colon cancer and cancer in

general is typically the result of organ damage caused by masses of

cancer cells that have grown so large that they interfere with normal

organ function.

 

The good news is that this is typically a slow process that takes

several years to develop. Although cancer may appear to progress very

rapidly once it is diagnosed, there are many steps between the initial

DNA damage and the mutations that must occur for a tumor or metastatic

cancer to develop to the point of being detectable.

 

Causes

The cells of the colon and rectum are constantly exposed to chemicals

that irritate them and that are considered carcinogenic, or

cancer-causing. Some of the main carcinogens are the bile salts produced

by the liver. These substances are secreted into the intestines to help

with digestion of fats in the diet.

 

Unfortunately, certain kinds of bacteria that live in the intestines can

convert these bile salts into carcinogenic substances. These carcinogens

can enter the cells themselves and damage the DNA, or they may increase

the amounts of pro-inflammatory chemicals, called prostaglandins, in the

area, which then leads to increased levels of free radicals. These free

radicals can then enter the cells and cause DNA damage.

 

In addition, certain substances found in food itself can be

carcinogenic. Some of the main types of carcinogens in the American diet

are called heterocyclic amines. These are formed in meats, including red

meat, chicken, and fish, when they are heated at very high temperatures,

such as during grilling, barbequing, broiling, or frying. Other types of

carcinogens, known as polycyclic aromatic hydrocarbons, can be formed in

foods when they are cooked over an open flame or smoked. These

carcinogens are dangerous to the cells of the colon and rectum and

produce the DNA damage that can lead to cancer.

 

Reducing one’s risk of developing colon cancer involves avoiding those

things that can increase risk. One risk that cannot be changed is

genetic susceptibility. Colon cancer tends to run in families and some

people carry genes that put them at a much higher risk for colon cancer

than others. Fortunately, though, genetic risk does not guarantee that

one will wind up with colorectal cancer. Many other risk factors can be

modified to reduce the possibility of developing this disease.

 

For example, obesity and a lack of physical activity are both associated

with an increased risk for colon cancer. Studies have shown that people

who are obese have an increased incidence of colon cancer. It's unknown

whether this is due to lack of physical activity or certain dietary

habits that are associated with obesity and are also risk factors, or

whether it is something to do with the obesity itself.

 

Also, even moderate physical activity and exercise can greatly reduce

one’s risk for developing colon cancer, by as much as 50% according to

some studies. In addition to other benefits, such as increased

circulation and improved immune function, moderate physical activity can

improve the movement of food through the colon, thereby reducing the

amount of time that the colon cells spend in contact with carcinogenic

chemicals and bile salts. Another important risk factor for colon cancer

development is cigarette smoking. By far the most important factor in

reducing colorectal cancer risk is diet.

 

Dietary Causes

Diet is considered the most important factor in the development of

colorectal cancer. Some researchers report that differences in dietary

habits account for up to 90% of the differences in incidence rates seen

between different areas of the world.

 

Other researchers propose that dietary factors may explain up to 90% of

all cases of colon cancer. The main dietary factors that contribute to

an increased risk of colon cancer include total fat intake, saturated or

animal fat intake, consumption of red meat, processed meats and meat

cooked at very high temperatures, sugar consumption, alcohol use,

especially commercial beer, and overeating.

 

In contrast, diets high in organic vegetables, total fiber, fruits,

fish, whole grains, and fermented dairy products such as yogurt, have

all been shown to significantly reduce one’s risk of developing colon

cancer.

 

Nutrient Needs

Nutrients That May Reduce Risk of Colorectal Cancer

 

Fiber

It's estimated that colon cancer risk in the United States could be

reduced by 31% with even a moderate increase in daily fiber intake.

Other studies show up to a 50% decrease in risk with increased

consumption of fiber-rich foods. A study published in the November 2003

issue of JAMA confirms the association between higher consumption of

cereal fiber and a lower risk of colon cancer. The study, a 35-month

prospective trial involving 3,121 patients aged 50 to 75 years found an

inverse association between consumption of cereal fiber (fiber intake

more than 4.2 grams per day), vitamin D (intake greater than 645 IU per

day), and the daily use of non-steroidal anti-inflammatory drugs (NSAIDS

such as aspirin) and colon cancer. High intake of fiber reduced colon

cancer risk by 5%, and of vitamin D by 6%. Smoking was associated with

an 85% increased risk of colon cancer and current moderate to heavy

alcohol use with a 2% increase in risk. A diet rich in fiber and vitamin

D would provide an 11% reduction in colon cancer risk. (December 30,

2003)

 

 

Unfortunately, most people in the United States do not get nearly as

much fiber in their diets as they should be getting. Fiber decreases

colon cancer risk by several different mechanisms. One way is by binding

to bile salts.

 

As mentioned above, bile salts can be converted by certain intestinal

bacteria into carcinogens.

 

By binding to the bile salts, fiber helps to reduce this possibility.

Fiber also helps to add bulk to the stool, which results in a dilution

of the concentration of bile in the colon, further decreasing exposure.

 

By adding bulk to the stool, fiber also increases the rate at which

stool is eliminated from the body, reducing the amount of time that the

colon cells spend in contact with the bile salts.

 

Fiber also encourages the growth of beneficial bacteria in the large

intestine.

 

These bacteria have been shown to bind to certain carcinogens and also

to prevent the activation of other carcinogens that may occur in the

colon.

 

Fiber in the intestines can be fermented by normal flora to substances

called short chain fatty acids or volatile fatty acids. These substances

have been shown to have very beneficial effects on colon cells.

 

One of these chemicals, known as butyrate, is produced from a variety of

healthy foods, including root vegetables like chicory and burdock root,

onions and chives, asparagus, and whole grains like rye, wheat, and

oats.

 

Butyrate has been demonstrated to decrease the proliferation and

increase the apoptosis of mutated cells, while at the same time helping

to protect healthy cells from damage due to free radicals. It also acts

as a fuel source for colon cells, thereby supporting their healthy

function. Wheat bran itself has been shown in a number of studies to be

very good for the prevention of colon cancer.

 

Some excellent food sources of fiber include raspberries, mustard

greens, turnip greens, collard greens, broccoli, cauliflower, and Swiss

chard.

 

Calcium and Vitamin D

Higher intakes of calcium and vitamin D are associated with a

significant decrease in risk of both colon and rectal cancer. People

with low intake of these two nutrients have been shown to have twice the

risk of developing colorectal cancer as people with higher intakes.

Studies have shown that people with higher blood levels of vitamin D had

a 70% reduction in risk. These nutrients reduce colon cancer risk by

several mechanisms. Calcium has the ability to bind to bile salt, thus

reducing their exposure to colon cells. Both calcium and vitamin D have

been shown to reduce excessive proliferation of colon and rectal cells,

increase the normal process of apoptosis, and improve the necessary

differentiation of these cells. These effects have been demonstrated

even in those who continue to consume a high-fat diet, which has been

identified as another risk factor for colorectal cancer.

 

Diets high in calcium or in oxidation-resistant fats such as olive oil,

may prevent the possible cancer-promoting effect of red meat, suggests a

study published in the August 2003 issue of Carcinogenesis.

 

It’s generally accepted that a high intake of red meat, but not of white

meat, is associated with an increased risk of colon cancer. Researchers

believe this is due to the fact that red, but not white meat contains

haemin, a form of iron (specifically, a chloride of heme in which He2+

has become He3+).

 

It is thought that haemin, by promoting free radical formation and

activity, increases the cellular damage that ultimately results in colon

cancer. In this study, rats that already had abnormal colonic cell

growths (called aberrant crypt foci) were injected with a carcinogenic

chemical (azoxymethane) and then fed a variety of experimental high

haemin-containing diets. While in rats given only a high haemin diet,

free radical production and abnormal colonic cell growth escalated, in

those who were also supplemented with calcium or with olive oil and

antioxidants, free radical production remained normal and so did colon

cells.

 

Mustard greens, turnip greens, spinach and collard greens are some

excellent food sources of calcium. Shrimp and fortified milk are two

very good sources of vitamin D.

 

Folate

A high intake of folate, or folic acid, has been shown in several

studies to decrease the risk of colon cancer. One study showed the risk

of colon cancer in certain high-risk patients was reduced by 62% with a

high intake of folate. In addition, several studies have shown that

those who have a low intake of dietary folate are at a greatly increased

risk of developing colon cancer.

 

Folate is needed for the proper production of DNA in replicating cells.

Low folate has been shown to cause breakages of DNA, which can lead to

an increased rate of mutations, eventually contributing to the

development of cancer. The combination of a low folate diet and regular

alcohol use has been shown to especially increase the risk of colon

cancer. Getting enough folate in the diet is important for protecting

against these DNA mutations.

 

Excellent sources of folate include: spinach, parsley, broccoli,

beets,turnip greens, asparagus, romaine lettuce, lentils, and calf’s

liver.

 

Vitamin B12

Vitamin B12 is similar to folate in that it is also needed for the

proper production of DNA. Although there are few studies linking vitamin

B12 to colon cancer risk specifically, low levels of vitamin B12 have

been shown to lead to increased DNA breakage and mutations. People

increasing their folate intakes should make sure they are getting enough

vitamin B12 in their diets as well.

Excellent food sources of vitamin B12 include calf liver and snapper.

 

Selenium

Selenium is a mineral needed for the proper function of the antioxidant

system of the body. Several studies have shown that adequate amounts of

selenium in the diet can protect against many different types of cancer,

including colon cancer. A low selenium intake can lead to excessive

amounts of free radicals and damage to DNA.

In one study, patients who were given selenium-rich foods had a 58%

decreased risk for developing colon cancer. In order to gain the maximum

benefit from selenium, researchers recommend also following a low-fat

diet. Selenium is able to work best when there is an adequate intake of

vitamin E.

 

Some excellent sources of selenium include crimini mushrooms, cod,

shrimp, salmon, snapper, yellowfin tuna, and calf liver.

 

Vitamin E

Vitamin E is the main fat-soluble antioxidant in the body. It's needed

to decrease the levels of free radicals and prevent the damage they may

cause. It has also been shown to improve the function of the immune

system in the colon, allowing the body to combat cancer cells.

Studies have shown that those with the greatest intake of vitamin E have

approximately 1/3 the risk of developing colon cancer when compared to

those with the lowest intake. It's important that people increase their

intake of natural forms of vitamin E, not the synthetic forms found in

some supplements. Mustard greens, chard, turnip greens, and sunflower

seeds are a few excellent sources of vitamin E.

 

Vitamin C

Vitamin C is one of the main water-soluble antioxidants in the body.

It's also needed to decrease levels of free radicals that can cause

damage to cells. Also like vitamin E, vitamin C is needed for the proper

function of the immune system. Some studies have shown that vitamin C

intake can help to decrease the incidence of colon tumors. Other studies

have shown a link between increased vitamin C intake and a decreased

risk for colon cancer, possibly by as much as 40%.

Excellent food sources of vitamin C include broccoli, parsley, bell

peppers, strawberries, cauliflower, lemons, mustard greens, Brussels

sprouts, papaya, kale, cabbage, spinach, kiwifruit, cantaloupe, oranges,

grapefruit, tomatoes, chard, collard greens, raspberries, peppermint

leaves, asparagus, celery, fennel bulb, pineapple, and watermelon.

 

Beta-carotene

Beta-carotene and other carotenoids have been shown in some studies to

decrease the risks of developing both colon cancer and rectal cancer.

They work similarly to other antioxidants in decreasing the amount of

free radicals in the body. Carotenoids have also been shown to increase

cell differentiation and protect cells against carcinogenic chemicals

that could damage DNA. Vitamin A, which is structurally similar to

beta-carotene, may help to decrease risk by preventing excessive colon

cell proliferation and tumor formation. Excellent food sources of

vitamin A/beta-carotene include sweet potatoes, carrots, calf liver,

kale, winter squash, collard greens, chard, cantaloupe, mustard greens,

romaine lettuce, spinach, parsley, cayenne pepper, peppermint leaves,

Brussels sprouts, tomatoes, broccoli, asparagus, and apricots.

 

 

 

Lycopene

A carotenoid nutrient found in tomatoes (and everything made from them),

lycopene has been extensively studied for its antioxidant and

cancer-preventing properties. In contrast to many other food

phytonutrients, whose effects have only been studied in animals,

lycopene from tomatoes has been repeatedly studied in humans and found

to be protective against a growing list of cancers including colorectal

cancer.

A study published in the November 2003 issue of the American Journal of

Clinical Nutrition found that in patients with colorectal adenomas, a

type of polyp that is the precursor for most colorectal cancers, blood

levels of lycopene were 35% lower compared to study subjects with no

polyps. Blood levels of beta-carotene also tended to be 25.5% lower,

although according to researchers, this difference was not significant.

In their final (multiple logistic regression) analysis, only low levels

of plasma lycopene (less than 70 microgram per liter) and smoking

increased the likelihood of colorectal adenomas, but the increase in

risk was quite substantial: low levels of lycopene increased risk by

230% and smoking by 302%. Well known for being abundant in tomatoes and

particularly well absorbed from cooked tomato products containing a

little fat such as olive oil, lycopene is also present in high amounts

in watermelon and mangoes.

 

 

Omega-3 fatty acids

Omega-3 fatty acids are types of fats needed by our cells for proper

functioning. They're the main types of fats found in fish oils. Numerous

studies have shown a link between the intake of omega-3 fats, fish oils,

or fish in general and a decreased risk for colon cancer. EPA, a type of

omega-3 fatty acid found in fish oil, has been shown to decrease the

formation of tumors in the colon.

 

A study published in the July 2003 issue of Free Radical Biology may

help explain why. Omega-3 fats are believed to reduce colon cancer risk

by decreasing the production of the pro-inflammatory prostaglandins in

the intestines. Since inflammation produces free radicals and DNA

damage, decreasing the production of prostaglandins can prevent this

from occurring. In this study, when mice were given either fish oil or

corn oil (which is high in potentially inflammatory omega 6 fatty acids)

and then dosed with dextran sodium sulfate, a chemical known to provoke

an inflammatory response that can lead to DNA damage, not only did the

fish oil lessen the inflammatory response, but it also caused an

increase in the apoptosis of those cells that were damaged. (Apoptosis

is the self-destruct sequence the body uses to eliminate cancerous

cells).

 

 

A review of 91 studies on the relationship between diet and cancer

published in the October 2004 issue of the International Journal of

Cancer provides substantial evidence that diets rich in the omega-3 fats

found in cold water fish help prevent colon cancer. The review includes

studies conducted in the U.S., Canada, and 22 European countries which

show that the tumor-promoting effect seen with dietary fat depends on

which type of fat it is, and that colon cancer risk is related more to

what type, rather than how much fat is eaten. Although the ways in which

omega-3 fats exert their protective effects is not yet fully understood,

it appears that the fats a person eats affect the amount of bile acids

he or she excretes. People eating a typical Western diet, which is high

in saturated and omega-6 fats, who are at higher risk of colon cancer,

also excrete high levels of bile acids. Excess bile acids have been

shown to stimulate an inflammatory chemical called protein kinase C, to

induce cell proliferation, and act as promoters in colon carcinogenesis.

Omega-3 fats are thought to prevent carcinogen activation by decreasing

DNA-damage, enhancing DNA repair, and enhancing apoptosis (cell suicide)

in carcinogenic colonic cells.

 

Food sources of omega-3 fatty acids include flax seeds and walnuts as

well as cold water fish, like salmon, cod, tuna, and halibut.

 

Bioflavonoids

Bioflavonoids are a diverse group of substances naturally found in a

wide variety of fruits and vegetables. Certain bioflavonoids, like

quercitin, which can be found in cherries, white grapefruit, apples,

pears, grapes, cranberries, red onions, yellow onions, green cabbage,

spinach, kale, and garlic, have been shown to decrease the rates of

colon cancer in some animal studies. Although these substances have only

been used in animal studies so far, they show potential in possibly

being useful to help decrease colon cancer in humans as well.

 

Specific Foods That May Help Decrease Risk

Vegetables

A high intake of vegetables has been shown in numerous studies to be one

of the best means of decreasing colon cancer risk. Many studies have

shown that people who consume a diet high in vegetables have much lower

rates of colon cancer than those who don't eat a diet rich in these

foods.

 

Vegetables tend to be very high in many nutrients that have been shown

to be beneficial for preventing colorectal cancer, including fiber,

folate, vitamin C, beta-carotene, and a wide variety of bioflavonoids.

They also contain other substances which have been shown to increase the

ability of the body to inactivate harmful carcinogenic chemicals.

 

Unfortunately, studies show that 80% of American children and 68% of

American adults don’t get their recommended 5 servings of fruits and

vegetables every day. Increasing vegetable intake in general could go a

long way towards helping reduce the risk of colorectal cancer, as well

as many other diseases.

 

Specific types of vegetables that have been shown to be especially

helpful in the prevention of colon cancer include:

 

Brassicas

The term ‘brassica’ refers to a group of vegetables that includes

cabbage, kale, broccoli, cauliflower, brussel sprouts, kohlrabi,

turnips, and rutabagas. These vegetables have certain substances in them

known as isothiocyanates and indoles, which have been shown in research

studies to be especially good for protecting cells against the effects

of carcinogens and also for decreasing tumor development in the colon.

Some studies show that eating just two or more servings of these

vegetables a week can decrease colon cancer risk by 20-40%.

 

A study published in the April 2004 issue of Carcinogenesis explains at

least some of the reasons why eating cruciferous vegetables such as

broccoli, cauliflower, cabbage and Brussels sprouts is associated with a

reduction in colorectal cancer risk. It appears that when we eat

crucifers, the amounts of certain liver enzymes necessary for the

detoxification and clearance of carcinogens, such as the heterocyclic

amines found in cooked foods, particularly red meat, are greatly

increased. In this study, subjects avoided crucifers for 12 days (Period

1), ate broccoli and Brussels sprouts daily for 12 days (Period 2), and

again avoided crucifers for 12 days (Period 3). At the end of each 12

day period, subjects ate a cooked meat meal containing heterocyclic

amines. Consumption of cruciferous vegetables increased study subjects’

ability to detoxify and excrete heterocyclic amines to 127% and 136% of

levels seen in Periods 1 and 3, respectively.

The liver usually clears potentially harmful compounds using two

metabolic pathways: Phase 1, which uses the Cytochrome P450 family of

enzymes, and Phase 2, in which compounds activated in Phase 1 are

conjugated (joined) with carrier molecules and ferried out of the body.

In this study, the researchers found that activity in important parts of

both Phase I and Phase 2 (specifically, the Phase I liver detoxification

enzyme CYP1A2, and the Phase II glucuronidation conjugation pathway) was

significantly increased when broccoli and Brussels sprouts were eaten

daily.

 

Alliums

“Alliums” refers to a group of vegetables that includes onions, garlic,

leeks, chives, scallions, and shallots. Just two or more servings per

week can help to reduce the risk of colon cancer. These vegetables are

rich sources of substances called organosulfur compounds, or OSCs.

 

These OSCs have been shown to have anti-cancer activities that act at

every stage in the initial development and progression of cancer. They

increase the body’s ability to break down harmful chemicals. They're

also good at protecting against the effects of carcinogens, particularly

of heterocyclic amines, which are formed in the high-heat cooking of

meats. Cooking meat with onions, for example, has been shown to decrease

the ability of the cooked meat to cause DNA damage. Since the beneficial

substances in these foods tend to break down over time, fresh onions and

garlic are much better for reducing the negative effects of carcinogens

than just the oils or dried forms of the vegetables.

 

 

 

Soy Foods

A substance found in soybeans may reduce colon cancer risk, suggests

animal research conducted by Alfred Merrill at Emory University and the

Karmanos Cancer Institute.

 

The cancer-protective substance is a sphingolipid (a type of lipid or

fat that, in the body, is primarily used as a constituent of nerve

tissue) called soy glucosylceramide. Sphingolipids found in milk have

already been shown to inhibit the formation of tumors in mice exposed to

carcinogens known to cause colon cancer. While the sphingolipids found

in soy differ structurally from those found in milk, the soy compounds

had comparable effects.

 

When mice exposed to a carcinogen were given a diet containing 1% soy

glucosylceramide, the proliferation of colon cancer cells dropped by

56%. When the same diet was given to a strain of mice bred to

spontaneously develop colon cancer, the rate at which tumors formed

dropped 37%.

 

Soy sphingolipids provided this protection by affecting the expression

96 different genes in the cells that form the lining of the intestines,

increasing 32 and decreasing 64. Soy's effects on these genes resulted

in a decrease in the production of two factors associated with cancer

initiation and promotion: hypoxia-induced factor 1 alpha and

transcription factor 4. While other plants also contain sphingolipids,

soy contains relatively high amounts of glucosylceramide, which

researchers think may be one reason for the cancer-preventive effects of

eating soy foods.

 

 

 

Carrots

Although best known for their high content of beta carotene, carrots

also contain a phytonutrient called falcarinol that may be responsible

for the recognized epidemiological association between frequently eating

carrots and a reduced risk of cancers.

 

Falcarinol provides protection against colon cancer, suggests a study

published in the February 2005 issue of the Journal of Agricultural and

Food Chemistry. Three groups of rats in whom precancerous colon lesions

(aberrant crypt foci) had been chemically-induced were fed a standard

diet, one supplemented with freeze-dried carrots naturally containing

falcarinol, or one supplemented with an extract of falcarinol. After 18

weeks, precancerous lesions in the animals given diets containing

carrots or falcarinol were much smaller than those in the control

animals, and far fewer of the lesions had grown in size or progressed to

become tumors.

 

 

 

Fruits

A high intake of fruits has been associated with a decreased risk for

colon cancer in several studies. Fruits, like vegetables, contain other

beneficial nutrients including fiber, vitamin C, folate, carotenoids,

and bioflavonoids. The current recommendation is that people get at

least 5 servings of fruits and vegetables every day. It's best to

consume whole fruits instead of just juices since juices don’t usually

have all of the fiber and nutrients of the whole fruit. Also, variety is

the key to making sure that the diet contains many different nutrients

and bioflavonoids.

 

 

Grapefruit

Grapefruit are particularly recommended. Not only are grapefruit rich in

vitamin C, but new research presented August 2004 at the 228th National

Meeting of the American Chemical Society provides evidence that

grapefruit helps protect against lung and colon cancer.

 

In humans, drinking three 6-ounce glasses of grapefruit juice a day was

shown to reduce the activity of an enzyme that activates cancer-causing

chemicals found in tobacco smoke. In rats whose colons were injected

with carcinogens, grapefruit and its isolated active compounds

(apigenin, hesperidin, limonin, naringin, naringenin, nobiletin) not

only increased the suicide (apoptosis) of cancer cells, but also the

production of normal colon cells. Researchers also confirmed that

grapefruit may help prevent weight gain by lowering insulin levels, and

high insulin levels have also been linked to an increased risk for colon

and other cancers.

 

 

 

New insight into how grapefruit protects against cancer

Grapefruit juice significantly increases the production and activity of

liver detoxification enzymes responsible for preparing toxic compounds

for elimination from the body.

 

The liver clears out toxins, including carcinogens, using a two step

process called Phase I and Phase II detoxification. In the first part of

this process, Phase I, enzymes belonging to the cytochrome P450 family,

work on the toxin to make it more attractive to enzymes involved in the

second part of the process, Phase II. Unfortunately, the action of Phase

I enzymes often renders the toxin not only more attractive to Phase II

enzymes, but even more dangerous, and some foods contain compounds that

only increase the activity of Phase I without also turning up Phase II.

 

Grapefruit increases the activity not only of the Phase I enzyme CYP1A1,

but also that of NAD(P)H:quinone reductase 1, a Phase II detoxification

enzyme that protects cells against oxidative stress and toxic quinones.

The end result: grapefruit works in both Phase I and Phase II to enhance

the liver's ability to remove cancer-causing toxins.

 

Whole Grains

Whole grains are also an excellent source of nutrients like fiber, the

B-vitamins, and something called phytic acid. Phytic acid, also called

phytate, is a substance found in many types of whole grains, especially

wheat bran and oat. It has been shown in a number of studies to inhibit

the formation of tumors in the colon and other locations, to increase

apoptosis of mutated cells, and to reduce tumor growth. It's also found

in high quantities in legumes, including beans and peas.

 

It's important that people get plenty of these foods in their diet in

order to reduce the risk of colon cancer. Phytic acid can also bind

together with certain minerals, however, to lower their absorption; so

consumption of these phytate-containing whole foods should always be

part of a balanced, varied, whole foods diet.

 

Cold Water Fish

As mentioned earlier, several studies have shown that populations that

consume a good amount of fish have very low rates of colon cancer. This

may be due mainly to the omega-3 fatty acids, such as EPA and DHA, found

in fish. While other types of meat, particularly red meat, has been

shown to increase colon cancer risk, fish intake has been shown to be

protective. The best types of fish to consume are the cold-water fish,

like salmon, mackerel, herring, and cod, as they are richest in the

beneficial omega-3 oils.

 

Olive Oil

While overconsumption of certain types of fats, including omega-6 fats

found in certain vegetable oils and saturated fats found in animal

products, has been shown to increase the risk of colon cancer,

monounsaturated fats, such as those found in olive oil, have been shown

to be protective when consumed in appropriate amounts. As noted above in

the discussion of Calcium and Vitamin D under Nutrient Needs, a study

published in the August 2003 issue of Carcinogenesis suggests that olive

oil is particularly protective in individuals whose meals include red

meat. This is because olive oil is less susceptible to oxidation than

most other types of fat and is therefore less likely to be damaged by

the form of iron in red meat, haemin, which by promoting free radical

formation and activity, increases the cellular damage that ultimately

results in colon cancer.

Populations such as those in the Mediterranean area which have

relatively high intakes of olive oil typically have fairly low levels of

colon cancer. Other substances found in olive oil, such as squalene and

lignans, have also been shown to reduce colon cancer formation.

 

Turmeric

Turmeric is a seasoning rich in a substance known as curcumin. Curcumin

has been shown in several research studies to have very strong

antioxidant and anti-inflammatory actions in the body. In addition, it

has been shown to decrease the excessive cell proliferation and to

increase the apoptosis of mutated cells. In general, some studies have

shown that it may be useful in reducing the formation of colon tumors

and the development of colon cancer.

 

 

Ginger

Gingerols, the main active components in ginger and the ones responsible

for its distinctive flavor, may also inhibit the growth of human

colorectal cancer cells, suggests research presented at the Frontiers in

Cancer Prevention Research, a major meeting of cancer experts that took

place in Phoenix, AZ, October 26-30, 2003.

 

In this study, researchers from the University of Minesota’s Hormel

Institute fed mice specially bred to lack an immune system a half

milligram of -gingerol three times a week before and after injecting

human colorectal cancer cells into their flanks. Control mice received

no -gingerol.

 

Tumors first appeared 15 days after the mice were injected, but only 4

tumors were found in the group of -gingerol-treated mice compared to 13

in the control mice, plus the tumors in the -gingerol group were smaller

on average. Even by day 38, one mouse in the -gingerol group still had

no measurable tumors. By day 49, all the control mice had been

euthanized since their tumors had grown to one cubic centimeter (0.06

cubic inch), while tumors in 12 of the -gingerol treated mice still

averaged 0.5 cubic centimeter—half the maximum tumor size allowed before

euthanization.

 

Research associate professor Ann Bode noted, “These results strongly

suggest that ginger compounds may be effective chemopreventive and/or

chemotherapeutic agents for colorectal carcinomas.”

 

In this first round of experiments, mice were fed ginger before and

after tumor cells were injected. In the next round, researchers will

feed the mice ginger only after their tumors have grown to a certain

size. This will enable them to look at the question of whether a patient

could eat ginger to slow the metastasis of a nonoperable tumor. Are they

optimistic? The actions of the University of Minnesota strongly suggest

they are. The University has already applied for a patent on the use of

-gingerol as an anti-cancer agent and has licensed the technology to

Pediatric Pharmaceuticals (Iselin, N.J.).

 

Yogurt

Some studies have shown that populations that consume high levels of

yogurt and other fermented dairy products have a lower rate of colon

cancer than other populations. Fermented dairy products are rich in

certain types of beneficial bacteria, which normally live in the human

intestines. These bacteria have been shown to protect colon cells from

the damaging effects of carcinogens. These bacteria also bind to the

hazardous heterocyclic amines in meats, thereby reducing their contact

with the cells of the colon and rectum.

 

Harmful bacteria in the colon can actually activate some carcinogens,

making them more dangerous to the body than they were before. Beneficial

bacteria compete with and can reduce the numbers of these harmful

bacteria, thereby protecting the body from these additional carcinogens.

It's important that the yogurt and other products contain live, active

culture. For people who cannot tolerate or prefer not to consume dairy

products, several types of soy yogurts are now available.

 

Nutrient Excesses

Substances to Avoid

Fat

Many studies have shown a relationship between the amount of fat

consumed and the risk of colon cancer. Those who consume large amounts

of fat in their diets may have twice the risk of developing colon cancer

compared to those who consume low-fat diets.

 

Since bile is needed for the proper breakdown and digestion of fats, a

high intake of fat leads to an increased production of bile and bile

salts, which can be carcinogenic to the cells of the colon. The types of

fats that seem to present the greatest problems when consumed in

excessive amounts are saturated fats, found mostly in animal products

like meat and eggs, and omega-6 fats, found mostly in vegetable oils and

margarines.

 

Omega-6 fats are especially prone to the negative effects of free

radicals. Once oxidized by free radicals, these fats can lead to DNA

damage and eventually to cancer growth and spread. Reducing the overall

amount of fat in the diet and balancing the type of fat by including

oils such as olive oil and fish oils, can really help to decrease the

risk of colon cancer.

 

Meat

Several studies have shown that high intakes of meats, particularly red

meats and processed meats, are associated with an increased risk of

colon cancer. Poultry, fish and other sources of protein, such as

legumes, are not associated with an increased risk and may actually help

to lower risk.

 

The most detrimental type of meat that can be consumed is meat that has

been cooked at a high temperature, such as barbequed, grilled,

charcoal-grilled, broiled, and fried. High temperature cooking of meats,

including red meat, poultry, and fish, leads to the production of

chemicals called heterocyclic amines, which are very potent carcinogens

to the cells of the colon and rectum.

 

Direct flame-grilling and smoking produces another type of carcinogen,

called polycyclic aromatic hydrocarbons, which may be just as bad. These

chemicals can be avoided by cooking meats at lower temperatures through

stir-frying, baking, or poaching, and also by cooking meats with foods

that contain antioxidant bioflavonoids, such as garlic, onions, apples,

or soy products.

 

Overeating

Overeating in general has been linked to an increased risk for colon

cancer. People who consume lower calorie diets seem to have a lower risk

of developing colon cancer than those who consume more calories than

they need. Switching from a diet high in refined foods or animal

products to one that is high in whole grains, fruits, vegetables,

legumes, and fish can usually help to reduce calorie intake.

 

Sugar

One large study showed that people who consumed the largest amounts of

refined sugar, or sucrose, had an increased risk of colon cancer

compared to those who consumed less. Sugar has many negative effects on

the body, including decreasing the proper function of the immune system.

Although the exact mechanism whereby sugar may increase colon cancer is

not currently known, it may have something to do with an inability of

the immune system to detect and destroy cancer cells in those who

consume a lot of refined sugar.

 

Alcohol

Many studies have shown a strong association between regular intake of

alcoholic beverages and an increased risk of colon cancer, and

particularly rectal cancer. The risk seems to be the greatest with beer

consumption, though some studies show a link with wine and alcohol in

general. The negative effects of alcohol are greatest in people who also

have a low intake of folate, so people who continue to have some alcohol

in their diets need to be sure that they’re consuming enough dietary

folate. In general, though, those at risk for the development of

colorectal cancer should greatly limit their use of alcohol products.

 

Recommended Diet

Women who choose the naturally low glyceimc (GI) healthy way of eating

suggested on the World’s Healthiest Foods are much less likely to

develop colorectal cancer compared to women whose diet is largely

composed of sugar-rich, fiber-poor foods.

 

Researchers are beginning to think that a diet high glycemic load (i.e.,

a diet high in sugars and refined carbohydrates), which results in high

blood sugar and a drop in our cells’ ability to respond to insulin

(insulin resistance), may also create an internal environment that

promotes tumor growth. Data from a 7.9 year study involving 38,451 women

aged 45 or older from the Women’s Health Study that was published in the

February 2004 issue of the Journal of the National Cancer Institute,

shows that a high glycemic load diet is statistically significantly

associated with the development of colon cancer, increasing risk by a

whopping 285%! Glycemic index (GI) is a system that ranks foods based on

their immediate effect on raising blood sugar levels. A low GI food will

cause a small rise in blood sugar levels, whereas a high GI food can

trigger a large and rapid increase. Glycemic load (GL) is calculated by

multiplying the amount of carbohydrate in a serving by the GI and

dividing by 100. Basically, only a few whole foods such as potatoes and

bananas have a high GI, and even these can safely be part of the healthy

way of eating recommended on the World’s Healthiest Foods. Highly

processed, refined sugar-laden foods, however, have a very high GI and

GL. For a full explanation of GI and GL, including a guide to the GI of

the World’s Healthiest Foods, just click What is the Glycemic Index

 

So why should a high GI /GL diet increase colorectal cancer risk?

Researchers think a high GL increases insulin-like growth factors, which

could promote out of control cell replication or levels of C-reactive

protein, an inflammatory compound that, in high amounts, could

exacerbate pro-inflammatory responses, either locally or systemically.

Regardless of the mechanism involved, a high GL diet clearly increases

risk of colorectal cancer—yet another good reason to choose the

delicious and low GL way of eating our recipes and meal planners offer.

(March 25, 2004)

 

 

 

Need more evidence to convince you to try the healthy, low glycemic load

way of eating recommended on the World’s Healthiest Foods? A study

published in the April 2004 issue of the Journal of the National Cancer

Institute has found yet another indication of the strong link between

the high gylcemic diet that leads to insulin resistance and diabetes and

a significantly increased risk of colorectal cancer.

 

Researchers at Brigham and Women’s Hospital and Harvard Medical School

in Boston followed 14,916 male physicians for 13 years. The men with the

highest blood levels of C-peptide—a hormone that reflects insulin

levels, so higher C-peptide levels indicate higher levels of insulin in

the blood—had a 2.7 times the risk (that’s a 270% increase in risk!) of

developing colon and rectal cancers compared to men with the lowest

levels.

 

The researchers note that a diet high in calories and animal fat and low

in fiber, along with lack of exercise, promotes not only insulin

resistance and type 2 diabetes, but also colorectal cancer. Lowering

your C-peptide levels and risk of type 2 diabetes and colorectal cancer

is not only easy, but delicious—just rely on the outstanding recipes

created to help you enjoy your food and your health by George Mateljan.

Pressed for time? Use any of the many recipes George has carefully

crafted to take just 15 minutes to prepare. (May 6, 2004)

 

Perhaps the best diet for reducing the risk of colorectal cancer is one

that is high in vegetables, fruits, especially grapefruit (October 19,

2004), whole grains, cold-water fish, fermented dairy products like

yogurt, and legumes, especially soyfoods.

 

 

 

A study published in the January 2004 issue of the Journal of Nutrition

suggests that colon cancer may be a hormone-responsive cancer, and that

soy protein can not only help prevent its occurrence but can have a very

positive effect on the number and size of tumors that do occur. In this

study, female mice whose ovaries had been removed to limit their sources

of estrogen were exposed to an agent that causes colon tumors, then fed

five different diets designed to compare the effects of specific

ingredients, and followed for a year.

 

Diet One contained milk protein, and Diet Two, soy protein with no

isoflavones; both these diets were free of any kind of estrogen. The

remaining three diets contain soy protein plus an estrogenic component.

Diet Three contained soy protein and the isoflavone, genistein, a

phytoestrogen found in soy. Diet Four contained soy plus a mixture of

soy-derived isoflavones including genistein, and Diet Five contain

estrone, a naturally occurring human estrogen.

 

While the diet containing estrone was the most effective in preventing

colon cancer, all the soy/estrogen diets were also protective and even

those mice given soy protein with no estrogen-like factors that did

develop colon cancer had fewer and smaller tumors compared to mice given

milk protein. Lead researcher, Ruth MacDonald, professor of food science

at the University of Missouri, is now trying to determine how soy

compounds protect against colon cancer. Until this work is done,

however, she notes that not only is soy protein thought to also be

helpful in the prevention of heart disease, but “the good news is that

there are many ways to add soy to your diet now, and we know of no

harmful side-effects to eating soy protein.” (March 25, 2004)

 

The consumption of saturated fats, from food like meats and eggs, should

be limited. Red meat and processed meats should be replaced by other

protein sources, such as poultry, cold water fish, such as salmon,

mackerel, herring, and cod, and legumes, especially soybeans, and all

meats should be cooked at lower temperatures through stir-frying,

baking, or poaching, and not cooked at high temperatures through

grilling, charcoal-grilling, barbequing, broiling, or frying.

 

When eating meat, cooking with foods such as onions, garlic, apples, or

soy products like miso is also recommended.

 

Omega-6 fats, found in vegetable oils and margarines, should be limited

and accompanied by use of oils like olive oil.

 

Brassica vegetables, such as broccoli, cauliflower, turnips, brussel

sprouts, rutabaga, cabbage, kale, and kohlrabi, and allium vegetables,

such as onions, garlic, chives, shallots, leeks and scallions, should be

eaten at least twice a week for the benefits that they offer.

 

Low-fat, vitamin D-fortified dairy products, especially those that

contain live bacteria culture, can provide good amounts of calcium and

vitamin D to further decrease risk.

 

Alcohol intake should be greatly limited or, in people who are at high

risk for rectal cancer, avoided completely.

 

Refined sugar should be removed from the diet.

 

In general, food consumption should not be excessive, but should provide

just enough calories to support a healthy lifestyle that includes a

moderate amount of exercise.

 

The Condition Specific Meal Planner for Colorectal Cancer has menus that

cover the nutritional needs of this condition over a four day period.

 

References

Ames, BN. Micronutrient deficiencies. A major cause of DNA damage. Ann N

Y Acad Sci 1999;889:152-6.

Bancroft LK, Lupton JR, Davidson LA, Taddeo SS, Murphy ME, Carroll RJ,

Chapkin RS. Dietary fish oil reduces oxidative DNA damage in rat

colonocytes. Free Radic Biol Med Jul 15;35(2):149-59.

Bartsch H, Nair J, Owen RW. Dietary polyunsaturated fatty acids and

cancers of the breast and colorectum: emerging evidence for their role

as risk modifiers. Ann N Y Acad Sci 1999;889:87-106.

Biasco G, Paganelli GM. European trials on dietary supplementation for

cancer prevention. Oncology (Huntingt) 1999;13:89-97; discussion 97-100,

105.

Bode A. Ginger is an effective inhibitor of HCT116 human colorectal

carcinoma in vivo. paper presented at the Frontiers in Cancer Prevention

Research Conference, Phoenix, AZ, Ocbober 26-3-, 2003.

Eastwood, GL. Pharmacologic prevention of colonic neoplasms. Effects of

calcium, vitamins, omega fatty acids, and nonsteroidal anti-inflammatory

drugs. Cancer Causes Control 1997;8:786-802.

Erhardt JG, Meisner C, Bode JC, Bode C. Lycopene, beta-carotene, and

colorectal adenomas. Am J Clin Nutr. 2003 Dec;78(6):1219-24.

Garay CA, Engstrom PF. Chemoprevention of colorectal cancer: dietary and

pharmacologic approaches. J Natl Cancer Inst 1997;89:1006-14.

Giovannucci E, Willett WC. Dietary factors and risk of colon cancer. Dig

Dis 1996;14:119-28.

Guo JY, Li X, Browning JD Jr, Rottinghaus GE, Lubahn DB, Constantinou A,

Bennink M, MacDonald RS. Dietary soy isoflavones and estrone protect

ovariectomized ERalphaKO and wild-type mice from carcinogen-induced

colon cancer. J Nutr. 2004 Jan;134(1):179-82. .

Hahn-Obercyger M, Stark AH, Madar Z. Grapefruit and Oroblanco Enhance

Hepatic Detoxification Enzymes in Rats: Possible Role in Protection

against Chemical Carcinogenesis. J Agric Food Chem. 2005 Mar

9;53(5):1828-32.

Higginbotham S, Zhang ZF, Lee IM, Cook NR, Giovannucci E, Buring JE, Liu

S. Dietary glycemic load and risk of colorectal cancer in the Women's

Health Study. J Natl Cancer Inst. 2004 Feb 4;96(3):229-33.

Kobaek-Larsen M, Christensen LP, Vach W, Ritskes-Hoitinga J, Brandt K.

Inhibitory Effects of Feeding with Carrots or (-)-Falcarinol on

Development of Azoxymethane-Induced Preneoplastic Lesions in the Rat

Colon. J Agric Food Chem. 2005 Mar 9;53(5):1823-1827.

Le Bon, AM, Siess, MH. Organosulfur compounds from Allium and the

chemoprevention of cancer. Cancer Causes Control 1996;7:127-46.

Lieberman D, Prindiville S, Weiss D, Willett W. Risk factors for

advanced colonic neoplasia and hyperplastic polyps in asymptomatic

individuals. JAMA. 2003;290:2959-2967.

Lipkin M, Reddy B, et al. Dietary factors in human colorectal cancer.

Ann Med 1994;26:443-52.

Lupton, JR, Turner, ND. Potential protective mechanisms of wheat bran

fiber. Am J Clin Nutr 1994;59:1162S-5S.

Ma J, Giovannucci E, Pollak M, Leavitt A, Tao Y, Gaziano JM, Stampfer

MJ. A prospective study of plasma C-peptide and colorectal cancer risk

in men. J Natl Cancer Inst 2004 Apr 7;96(7):546-53. .

Patterson RE, White E, et al. Vitamin supplements and cancer risk: the

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Peters HP, De Vries WR, et al. Potential benefits and hazards of

physical activity and exercise on the gastrointestinal tract. Gut

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1 [Epub ahead of print].

Potter, JD. Nutrition and colorectal cancer. Carcinogenesis

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Reddy B. Omega-3 fatty acids in colorectal cancer prevention.

International Journal of Cancer Oct 2004, 112(1):1-7.

Stone, WL, Papas, AM. Tocopherols and the etiology of colon cancer. Annu

Rev Nutr 1999;19:545-86.

Suzuki, Kohno H, Sugie S, Murkami A, Yano M, Ohigashi H, Tanaka T.

Citrus nobiletin inhibits azoxymethane-inducved rat colon

carcinogenecis. The 228th ACS National Meeting, Philadelphia, PA, August

24, 2004.

Symolon H, Schmelz EM, Dillehay DL, Merrill AH Jr. Dietary soy

sphingolipids suppress tumorigenesis and gene expression in

1,2-dimethylhydrazine-treated CF1 mice and ApcMin/+ mice. J Nutr. 2004

May;134(5):1157-61.

Terry P, Jain M, Miller AB et al. Dietary intake of folic acid and

colorectal cancer risk in a cohort of women. Int J Cancer 2002 Feb

20;97(6):864-7.

Turner, Vanamala J, Leonardi T, Patil B, Murphy M, Wang N, Pike L, et

al. Grapefruit and its isolated bioactive compounds act as colon cancer

chemoprotectants in rats. The 228th ACS National Meeting, Philadelphia,

PA, August 24, 2004.

Verhoeven DT, Goldbohm RA, et al. Epidemiological studies on brassica

vegetables and cancer risk. Am J Med 1999;106:24S-7S.

Walters DG, Young PJ, Agus C, Knize MG, Boobis AR, Gooderham NJ, Lake

BG. Cruciferous vegetable consumption alters the metabolism of the

dietary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine

(PhIP) in humans. Carcinogenesis. 2004 Apr 8 [Epub ahead of print].

Willett WC. Micronutrients and cancer risk. Cancer Epidemiol Biomarkers

Prev 1996;5:733-48.

Wollowski I, Rechkemmer G, Pool-Zobel BL. Protective role of probiotics

and prebiotics in colon cancer. Am J Clin Nutr 2001;73:451S-5S.

Wu K, Willet WC, Fuchs CS et al. Calcium intake and risk of colon cancer

in women and men. J Natl Cancer Inst 2002 Mar 20;94(6):437-46.

 

Send us your favorite recipes using the World's Healthiest Foods, so we

can share them with others!

_________________

_________________

JoAnn Guest

mrsjo-

DietaryTi-

www.geocities.com/mrsjoguest/Genes

 

======================================================

Posted: Tue May 24, 2005 4:32 pm

 

The

antioxidant/anticancer potential of phenolic compounds i

 

--

 

 

The antioxidant/anticancer potential of phenolic compounds isolated from

olive oil.

 

Eur J Cancer Jun00;36(10):1235-47

http://www.mindfully.org/Health/Olive-Oil-Phenolic.htm

 

Owen RW, Giacosa A, Hull WE, Haubner R, Spiegelhalder B, Bartsch H

Division of Toxicology and Cancer Risk Factors, German Cancer Research

Centre, Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany.

r.o-

 

In our ongoing studies on the chemoprevention of cancer we have a

particular interest in the health benefits of the Mediterranean diet, of

which olive oil is a major component. Recent studies have shown that

extravirgin olive oil contains an abundance of phenolic antioxidants

including simple phenols (hydroxytyrosol, tyrosol), aldehydic

secoiridoids, flavonoids and lignans (acetoxypinoresinol, pinoresinol).

 

All of these phenolic substances are potent inhibitors of reactive

oxygen species attack on, e.g. salicylic acid, 2-deoxyguanosine.

Currently there is growing evidence that reactive oxygen species are

involved in the aetiology of fat-related neoplasms such as cancer of the

breast and colorectum.

 

A plausible mechanism is a high intake of omega-6 polyunsaturated fatty

acids which are especially prone to lipid peroxidation initiated and

propagated by reactive oxygen species, leading to the formation (via

alpha,beta-unsaturated aldehydes such as trans-4-hydroxy-2-nonenal) of

highly pro-mutagenic exocyclic DNA adducts.

 

Previous studies have shown that the colonic mucosa of cancer patients

and those suffering from predisposing inflammatory conditions such as

ulcerative colitis and Crohn's disease generates appreciably higher

quantities of reactive oxygen species compared with normal tissue.

 

We have extended these studies by developing accurate high performance

liquid chromatography (HPLC) methods for the quantitation of reactive

oxygen species generated by the faecal matrix.

 

The data shows that the faecal matrix supports the generation of

reactive oxygen species in abundance.

 

As yet, there is a dearth of evidence linking this capacity to actual

components of the diet which may influence the colorectal milieu.

 

However, using the newly developed methodology we can demonstrate that

the antioxidant phenolic compounds present in olive oil are potent

inhibitors of free radical generation by the faecal matrix.

 

This indicates that the study of the inter-relation between reactive

oxygen species and dietary antioxidants is an area of great promise for

elucidating mechanisms of colorectal carcinogenesis and possible future

chemopreventive strategies.

_________________

 

JoAnn Guest

mrsjo-

DietaryTi-

www.geocities.com/mrsjoguest/Genes

 

 

 

 

 

AIM Barleygreen

" Wisdom of the Past, Food of the Future "

 

http://www.geocities.com/mrsjoguest/Diets.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

!