My Bladder Cancer Fight

 

Previous posts on this topic:
The Role Of Vitamin In The Prevention Of Cancer

The Role Of Vegetables In The Prevention Of Cancer

The Role Of Fruit In The Prevention Of Cancer

Add Or Remove These Types Of Foods to Your Diet

Food And Cancer

The Role Of Food In The Prevention Of Cancer

 

Red meat and processed meat are associated with an increased risk of colorectal cancer, and there is also
suggested evidence for some other cancers, such as prostate cancer. Red meat refers to beef, pork, and lamb, although some studies have included all processed meats (such as bacon, sausage, hot dogs, and cold cuts) in their definition regardless of their animal origin. Some research has suggested that processed, but not fresh meat may increase risk. More research is needed to understand how these meats influence cancer risk. The increased risk may be due to the iron and fat in red meat, and/or the salt and nitrates/nitrites in processed meat. Additionally, when meat is cooked at high temperatures, substances are formed that may be mutagenic or carcinogenic.

Red Meat and Processed Meats

Meat consumption in relation to cancer risk has been reported in over a hundred epidemiological studies from many countries with diverse diets. The association between meat intake and cancer risk has been evaluated by looking both at broad groupings of total meat intake, and also at finer categorizations, particularly intakes of red meat, which includes beef, lamb, pork, and veal, and also more specifically processed meats, which includes meats preserved by salting, smoking, or curing.

Meat consumption

Diet has a powerful influence on many diseases, including America’s number two killer, cancer. But because cancer is so complex, with many genetic and environmental factors affecting risk, the link between your menu and your risk has been hard to decipher. In the case of red meat and colon cancer, however, new research provides a plausible explanation for a long-suspected association.

Diet a powerful influence

As his profile at the School of Public Health notes, he has been involved in work “a positive association between animal fat and red meat consumption and risk of colon cancer.” This association is significant because colorectal cancer accounts for some 56,000 deaths each year in the U.S. (other risk factors include obesity, smoking, a diet low in vegetables and fruit, a diet high in animal fat, heavy alcohol consumption, and low physical activity). But it is an association that has been contentious and inconclusive, depending on which study you looked at.

Animal fat and colon cancer

The verdict: Eating large amounts of red or processed meat over a long period of time can indeed raise colorectal cancer risk. But the risks from such a diet are smaller than those from obesity and lack of exercise, both for colon cancer and for overall health.

Eating large amounts of red meat

Scientists have offered a number of explanations for the link between red meat and colon cancer, and a study from England offers a new explanation. The investigation recruited healthy volunteers who agreed to stay in a metabolic research unit where their diet could be carefully controlled and all of their fecal waste could be collected and analyzed. The volunteers ate one of three test diets for a period of 15 to 21 days. The first diet contained about 14 ounces of red meat a day, always prepared to minimize HCA (need to spell out this abbreviation afater initial use) formation. The second diet was strictly vegetarian, and the third contained large amounts of both red meat and dietary fiber.

Scientific study

The people who ate the most red meat in both time periods were 30%-40% more likely to develop cancer in the lower part of the colon, compared to people who ate the least. People who ate the most processed meats were 50% more likely to develop colon cancer and 20% more likely to develop rectal cancer compared to those who ate the least.

Eating large amounts of red meat can cause cancer in lower colon

The reason the senators are concerned is that on Nov 1, the World Cancer Research Fund (WCRF) will publish its 2007 report on “Food, Nutrition, Physical Activity and the Prevention of Cancer – an update to its 1997 report, which will evaluate some 5,000 to 10,000 new studies on cancer completed over the past 10 years. Professor Willett is a member of the WCRF’s 2007 expert panel.

Update to 1997 report

For colorectal cancer, a 24% increased risk with red meat consumption of 62.5 g/1,000 kcal and a 20% increased risk with processed meat consumption of 22.6 g/1,000 kcal was observed among both men and women, which is similar in magnitude to the summary relative risks observed in previous meta-analyses [22–24]. The researchers also found that increasing intakes of red meat were significantly associated with elevated risks of 20%–60% for cancers of the esophagus, liver, and lung. For processed meats, a 16% increased risk of lung cancer was observed. Red and processed meat intake was associated with an increased pancreatic cancer risk in men only.

Colo-rectal cancer

The researchers allowed for factors such as smoking that might have affected cancer incidence, but it remains possible that other life-style factors may have had an influence. The study’s definitions of red meat and processed meat overlapped; bacon and ham, for example, were included in both categories. Thus, exactly which type of meat causes which type of cancer remains unclear. Most of the study participants were non-Hispanic white, so these findings may not apply to people with different genetic backgrounds. Nevertheless, they add to the evidence that suggests that decreased consumption of red and processed meats could reduce the incidence of several types of cancer.

Bacon and Ham

Perhaps these extra studies will sufficiently alter the original study to show a positive association between increased red meat consumption and colorectal cancer, or perhaps not. Either way, there will always be new studies.

Positive or negative in future

To be continued in next post

Posted on June 6th, 2008 by Neil
Filed under: Bladder Cancer - Background, Cancer Prevention, My Cancer, Nutrition