Preventing Cancer with Food and Lifestyle
A. According to the newest American Cancer Societies’ publication “Cancer Facts & Figures—1998, the new cases of cancer rate in for the first time in years decreasing, from 1,382,400 in 1997, to a predicted 1,228,600 for 1998. Unfortunately, the numbers of deaths from cancer is predicted to increase, from 560,000 deaths in 1997 to 564,800 in 1998. Fortunately, the rate of some cancers have decreased, but certain other cancers have increased in number, enough so that when the figures are combined, the overall total annual death rate (from all sites), continues to be more than any previous year.
1,382,400 new cases in 1997, all sites
560,000 deaths predicted
[A. Cancer Death Rates]
When Richard Nixon declared war on cancer in 1971, the focus was on finding new treatments for the disease. Today researchers say the war on cancer can best be won by preventing the disease from occurring in the first place. A review of more than 4,500 studies concluded that Americans needed to make eating changes and exercise more. The American Cancer Society estimates that about one-third of U.S. cancer deaths are due to dietary factors. Other researchers suggest that diet could be responsible for up to 70 percent. [Mark Messina]
hear from some of
Researchers Agree that Cancer is Preventable
B. The Director of the NCI Div. of Cancer Prevention says, “…a diet rich in fruits and vegetables has a protective effect against cancer…about half the risk of people with low intakes.” [B. Authorities On Diet & Cancer-1]
C. Former Surgeon General C. Everett Koop summarized his extensive research into the causes of cancer by saying, “…many cancers have external causes and, in principle, should therefore be preventable.”
Examples of internal causes are hereditary, age, sex. External causes result usually from what we do to ourselves, like smoking, eating the wrong foods, lack of regular exercise. [C. Surg Gen-Preventable]
D. Surgeon General Koop summarizes in two points what he found from researching the literature as to how to prevent cancer.
1. Stop smoking
2. Make common sense dietary changes
[E. Two Steps to Prevent]
E. Secretary of Health Louis Sullivan also states that there is clearly a protective effect from eating a diet with plenty of fruits and vegetables. Unfortunately, his statement finishes with a
“but Americans are not reaching the basic goal of five or more servings each day.” [F. Authorities On Diet & Cancer-2]
We read from the director of National Cancer Institute’s division of Cancer Prevention that those who eat freely of fruits and vegetables are statistically at one-half the risk of cancer of all types. We read from the former Surgeon General that his research leads him to conclude that many cancers are the result of external causes. He identified smoking and diet as the two major causes.
What happens for those who do eat their fair share or more of fruits and vegetables?
What do fruits and vegetables have that makes them perhaps our number one choice for preventing cancer?
Evidence now suggests that vegetables may protect against colon and rectal cancer because of the antioxidant compounds they contain and/or their fiber content. Physical activity seems to reduce the risk of colon cancer by stimulating peristalsis--contractions of the intestine that propel fecal matter through the colon and rectum. That movement cuts down on the time the stool--and the toxins it contains--resides in the colon.
Avoiding alcohol and eating a produce-rich diet to prevent breast cancer has the most support by science. Dozens of studies have shown that the more alcohol a woman consumes, the greater her risk of breast cancer. Alcohol may inhibit certain cell-repair mechanisms in breast tissue or make cell membranes more prone to cancer. Another possibility is that alcohol boosts levels of estrogen--a hormone that may promote the growth of breast cancer.
Evidence suggests that fruit and vegetable consumption may also decrease breast cancer risk. Fruits and vegetables contain protective phytochemicals, that accelerate the actions of enzymes in the body and then bind these harmful toxins.
Also, there is evidence that dietary fat plays a role in breast cancer. The evidence is not positive at this point, but nevertheless there seems to be an association with the more fat in the diet the more cases of breast cancer. Saturated fat is particularly suspect.
The final risk factor for breast cancer also relates to diet, is that of obesity. Particularly in postmenopausal women, possibly because estrogen levels tend to run higher in overweight women as compared to those who are slimmer. 
Another example is prostate cancer. Some research suggests that a diet high in fat, especially from red meat, possibly increases the risk of prostate cancer. Other studies have shown that a high vegetable consumption can lower the risk of prostate cancer. The phytochemical lycopene, found in tomatoes (and strawberries) that makes them red, may lower the risk of prostate cancer. Lycopene is best absorbed by the body when tomatoes are cooked; tomato paste and sauce are good sources of the substance. 
One other example of the benefits of eating the kinds of food are the studies linking diets rich in fruits and vegetables to a reduced risk of lung cancer, cancer of the mouth, throat, esophagus, and larynx (voice box). 
Now in a practical way, how can we increase our consumption of these protective fruits and vegetables, so rich in phytochemicals, antioxidants, fiber and maybe compounds we haven’t even been able to identify yet?
In harmony with the research of the last decade, the United States Department of Agriculture in 1992, unveiled a new food-eating guide, called the Food Guide Pyramid.
F. Review the Food Guide Pyramid [Food Guide Pyramid]
This food pyramid moved Americans from the decades old four-food group model that gave equal importance to the meat and milk group as is did to the fruits, vegetables and grains. The pyramid begins at its base emphasizing grains found in bread, cereal, rice, or pasta. Then the next level of emphasis is the fruit and vegetable group. Americans have not be serious about eating an abundance of these foods, but today, if we have not already done so, is the day to decide for eating according to the guides recommendation. A wealth of research clearly underscores the practicality of these recommendations. At breakfast we can emphasize the fruits. A banana and a half cup of strawberries would give us two servings, or eating a whole grapefruit and a cup of applesauce over say whole wheat toast and peanut butter would give us four servings of fruits. At lunch, perhaps the most challenging for so many, who work deserves our best efforts for the best health. Taking vegetables in our lunch to cook in a microwave is an option for some. We encourage eating the majority of our food in our breakfast in mid-day meal, and eating lightly, if at all at night. The body can best use the calories earlier in the day. Late evening meals are often heavy and interfere with quality sleep, not to mention readily contribute to extra pounds.
G. The American Cancer Society list ten steps to reduce the risk of cancer. Notice that of the ten, eight of them are related to nutrition. Again emphasizing from yet another organization, one specializing in helping people prevent the disease, the importance of eating the most healthful diet.
[ACS Ten Steps to Prevent]
The Role of Fats in Cancer Risk
H. Notice that the ACS pointed out in point number 7, that we need to reduce the fat in our diet. Where do most fats come from in the American diet? [Animal products.]
[Foods High in Fat]
Numerous studies now indicate that fats in the diet are a definite risk factor for several different types of cancer—especially animal fats, and especially saturated fats which are more commonly found in animal fats rather than plant foods.
Speaking of fat, interestingly, the people of the Mediterranean area,
[Food Guide Pyramid-Mediterranean]
Unfortunately, when an American hears how beneficial olive oil appears, they add it to their diet, but don’t realize, that to really get the Mediterranean benefits, one also has to reduce many other animal products, especially meat and replace it with more quality complex carbohydrates such as pasta, whole grain rice, and more cereals.
J. Looking at fat consumption and cancer rates worldwide, in a sixteen country study it was demonstrated that as the amount of fat increased in the diet, the rate of cancer also increased. Those countries consuming the least amount of fat had the lowest cancer rates. [Fat & Breast Cancer-Worldwide]
The Role of Meat Eating, Eggs, Diary and Cancer Risk
K. One study from
L. Another way to study cancer risk is to study a particular sub-group who have many characteristics in common; a religious group of people lend themselves to this kind of background. For example, Seventh-day Adventists have been part of a U.S. Government sponsored study for more than twenty years, and those studies revealed that there is a definite ‘stair-step’ relationship, that is, the more meat in the diet the more cases of ovarian cancer.
M. Overall, Seventh-day Adventists are significantly below their share of cancers, about 50% of what is seen in the general population. Why? Approximately 50% of them are vegetarians who consume less fat, (especially saturated fat) and do consume more carbohydrates in the form of grains, fruits and vegetables.
Here are the statistics on seven cancers and the SDA rate. [SDA Ca Death Rates]
N. Although we do not know all the reasons why meat eating increases the risk of cancer, studies now indicate that one mechanism may be from the way the meat is cooked, making it carcinogenic.
Charcoal broiled meat and Benzopyrene
O. Even other methods of cooking meat can increase its role as a carcinogen, as well as the amount or frequency of eating meat.
[Meat Cooking-Colon Ca]
P. There are not many studies that look at the relationship of eggs, butter and cheese, but in one study it was found that the more that these foods were eaten, the higher the rate of breast cancer.
Being Overweight Increases Cancer Risk
Being overweight also increases our risk of various cancers. The diet that helps prevent cancer though, is also a diet lower in calories than the typical American normally eats. A diet that emphasizes grains, fruits, vegetables and nuts (in moderation) could be called “an anticancer diet” and more, it’s a diet low in calories and yet very filling.
Q. Obesity and cancer are often linked together. Obesity is defined as being 20% or more overweight. Studies show the more obese a person is, the higher their risk having cancer.
[Obesity Cancer Risk]
R. Being overweight is a problem anytime, but especially for women when they reach menopause.
What About Cultural Factors?
S. Sometimes we wonder if the reason certain the people of certain countries have lower rates of cancer is because they are inherently more protected. Not actually. When you study the Japanese, traditionally low in cancer of most kinds, when they move to a Western country and take up the Western lifestyle, they eventually end up with the same rates of cancer as the Westerners they became integrated with.
T. Affluence plays a role in cancer. The so-called 1st world countries have the highest rates of cancer, largely from their richer diets and sedentary lifestyles, compared to poorer countries that eat a low-fat, high-carbohydrate diet and exercise regularly.
[Affluence-World Rates & Colon Ca]
Protection Against Cancer by Diet
Recall how at the beginning of this lecture we quoted numerous nationally known authorities who made clear statements indicating cancer was largely preventable.
From the Journal of the National Cancer Institute, 1993, we read that “eighty percent of cancers potentially preventable by the right diet and healthy lifestyle practice.” Stopping smoking would reduce 26% of cancer, and most of the rest could be prevented by dietary changes and an active lifestyle.
Today we know that a diet rich in vitamins and minerals, from grains, fruits and vegetables are high in vitamin A, C, and E. These vitamins are becoming known for their antioxidant properties that deactivate free radicals, cells that have the potential of becoming carcinogenic. One recent study found that vitamin C and E was more effective if obtained from the plant source rather than from a supplement. [Antioxidants Free Radicals]
U. In this study it was found that a small amount of vitamin C and E from foods had a high antioxidant effect as compared to a much larger amount of those vitamins from supplements.
[Antioxidants free Radicals]
V. In a study of rabbits that were exposed to 24 weeks of ultraviolet light, 24% of the rabbits on a regular diet got skin cancer, but none of the rabbits that got the regular diet and extra vitamin C and E got skin cancer.
[Skin Cancer & Diet]
W. Obtaining an adequate amount of vitamins A, C, and E is very simple from our diet, if we are eating as recommended from the U.S. Food Guide Pyramid which recommends 6-11 servings of grains daily, 3-5 servings of vegetables, and 2-4 of fruits daily. The Recommended Daily Allowance for Vitamin A is between 800-1000 Retinol equivalents. From the food chart it is obvious that obtaining more than this amount daily from our food is simple.
[Vitamin A Sources]
X. The Recommended Daily Allowance for Vitamin C is only 60 milligrams. Again, very easy to obtain that and much more from our foods.
[Vitamin C Sources]
Y. The Recommended Daily Allowance for Vitamin E is 8 mg a-tocopherol equivalents, an impressive measurement, but see from the chart, not problem to get plenty of this friendly vitamin in our daily diet.
[Vitamin E Sources]
Z. Most of us have lost a loved one from cancer. But the Scripture tells us, the day is coming when we can live beyond any threat of cancer.
[No More Death]
These words for the future are most comforting. We know that in this life there are no guarantees against cancer, but the three proven steps we have enumerated, 1. Not using tobacco in any form, 2. Maintaining a regular program of physical activity, and 3. last but certainly not least, Eating a healthful diet, these three combined will give us the maximum protection possible.
1 Harvard Medical School, Harvard Health Letter, December 1997, p.1,2.
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