For a number of years it has been recognized that about 30 percent of cases of cancer are related to the things people eat. In the British Medical Journal of 1998 are found statements such as these:
Eighty percent of cancers of the large bowel, breast and prostate may be accounted for by diet. It also appears to contribute to the risk of other cancers such as prostate, pancreas, stomach and esophagus.
Fast forward to 2010 and in an article in the Oncology Nutrition Connection in the spring, the following concepts may be found: about one-third of the most common cancers in countries with high incomes and about one-fourth of those countries with low or middle income could be avoided by a good diet from plants, by physical activity and having a healthy weight.
Oncology, for the benefit of those who might not know, refers to the branch of medicine that deals with tumors, including cancers.
In this article the focus will be on foods and cancer. Part of the problem actually revolves around how some foods are cooked.
Substances called heterocyclic amines (HCA) are produced during the processing of meat and fish at temperatures above 273 degrees. For example the broiling of food or cooking over charcoal. It is not that difficult to get temperatures above that level.
At least 10 different HCAs have been identified in cooked meat and fish. It has been clearly proven that these HCAs cause cancers in animals (see Cancer Science 2004 or Tedsskkn Nor Laegeform 1999 -- a Norwegian journal).
The following will be a partial list of articles that suggest HCAs are part of of the cause of cancers in humans:
Very well done meat was associated with prostate cancer risk -- Cancer Research 2005.
Grilled meat is a risk factor for pancreatic cancer -- Mutation Research 2002 .
Red meat by itself which would include beef, pork, and lamb is associated with an elevated risk of colon cancer -- Cancer Research 1994, Journal of the National Cancer Institute 2005, and the European Journal of Cancer Prevention 2004.
In a meeting of the American Association for Cancer Research in 2010 it was pointed out that consumption of well-done meat nearly doubled the risk of getting bladder cancer.
Two studies showed that meat intake, especially red meat, was associated with a 50 percent increase in risk for pancreatic cancer (Journal of the National Cancer Institute 2005 and the Cancer Epidemiological Biomarkers Prevention 2007).
Red meat increased the risk of liver cancer and white meat possibly reduced the risk, according to the National Cancer Institute (2010). It also increased the risk for esophageal cancer. (American Journal of Gastroenterology 2011).
In a study done on Danish women an association between meat consumption and breast cancer was found but only in genetically susceptible women. (European Journal of Cancer Research 2008).
Now to look at this from a different point of view. Since the role of meat in the causation of cancer has been discussed how do vegetarians make out?
Two studies have been done in Great Britain comparing vegetarians and meat eaters. The first study done in 1999 showed the vegetarians had a significantly lower risk for all cancers. American Journal of Clinical Nutrition 1999. The second study looked at 61,566 British men and women. There were 32,403 meat eaters, 8,561 non-meat eaters who ate fish, and 20,601 vegetarians. The vegetarians had a 12 percent lower chance of getting cancer. When it came to cancers of the blood such as leukemia, multilple myeloma, and non-Hodgkins lymphoma, they were reduced by as much as 45 percent .
The low key conclusion of the authors was , "the incidence of some cancers may be lower in fish eaters and vegetarians than meat eaters. (British Journal of Cancer, 2009)
What about Seventh-day Adventists, since a significant percentage are vegetarians? Information from the Adventist Health Study 1, which was funded by the U.S. government, showed that for many cancers, Adventists had lower rates. This was not true however for prostate and uterus cancers and lymphomas. See the book "Diet, Life Expectancy, and Chronic Disease" by Gary E.Fraser (pages 38-91) for more.
Now for an important question. As far as food is concerned, what can be eaten to help prevent cancer? According to the American Cancer Society, the American Institute Institute for Cancer Research, Oncology Nutrition Connection, Spring 2010, and the International Journal of Cancer 2003, folks should eat a healthy plant-based diet.
And what is it in plants that makes the difference? It appears to be all of the antioxidant phytochemicals which, in general, are much higher in plants than in flesh foods.
Another thing to meditate on: Everyone has cancer cells floating around in their blood stream. Generally the body's immune system destroys those cells.
An important part of the immune system is what has been called "natural killer cells" whose job it is to destroy cancer cells. In an interesting study done in Germany at their Cancer Institute and reported in Nutriton and Cancer 1989 the killer cells' activity in a group of vegetarian men ages 28-50 was compared with the killer cell activity in male omnivores (people who eat both plants and animals) of the same age.
The natural killer cells of the vegetarians were twice as effective as those of the omnivores.
Finally we must ask, do the scientists and the American Cancer Society (say that it has been proven that eating meat causes cancer? No they don't.
They prefer to use the word "association" when it comes to describing the relationship between the cancers and the eating of flesh foods. I suggest that people who are into computers should type into their search engine such as Google these words " Cancer and food" and scroll down to "ACS Guidelines on Nutritional and Physical Activity for Cancer Prevention.
As for myself, having been a vegetarian since about the age of 15 and having considered all of the pluses and minuses of that lifestyle, I can only admit to being a very happy vegetarian.
I also admit to having wondered how many people if they had to go out and kill the animal themselves would continue to eat meat.
Dr. Don Casebolt of College Place is a retired physician who is passionate about preventive medicine. He spent 4 years as a medical officer in the U.S. Navy, the last 21/2 years as a flight surgeon. He also worked on the Navajo Reservation for 22 years.