Red Meat Consumption Linked To Colorectal Cancer

Colorectal cancer, or cancer of the rectum and large intestine (colon), is a major public health problem in every corner of the developed world. Roughly speaking, a diet containing less than 40 grams of animal fat per day conveys one-half the risk of colon cancer of a diet containing 65 grams or more per day. Similarly, a diet containing 60 grams or less of red meat per day carries half the risk of a diet containing 130 grams or more per day.

According to recent findings issued by the American Institute for Cancer Research (AICR), consuming more than 18 ounces, or a little over a pound, of red meat (pork, beef, lamb and goat) each week can significantly increase a person's risks for developing colorectal cancer. In addition, every ounce and a half of red meat a person eats over 18 ounces increases their risks by 15 percent.

Red meat contains substances linked to colon cancer. For example, some studies suggest that the heme iron (the compound that gives red meat its color) may increase the risk of developing colon cancer. Furthermore, heavily cooked or well-done meat, in which the surface is browned or blackened, contains substances called heterocyclic amines, which in a laboratory setting have been found to cause cancer.

AICR recommends that two-thirds of a meal consist of plant-based foods. Consuming less red meat and more plant-based foods can significantly decrease a person's risks of developing colorectal cancer.

Don't Eliminate Red Meat

These recommendations are not meant to encourage people to completely eliminate red meat from their diet. Consuming red meat in modest amounts is a valuable source of nutrients, including protein, iron, zinc and vitamin B12. Moderation is the key.

Try serving about three ounces (about the size of a deck of cards) of cooked red meat at meals.

Avoid Processed Meats

AICR also recommends eating very little processed meat (meat preserved by smoking, curing, salting or adding chemical preservatives), such as ham, bacon, hot dogs, sausages, pastrami and salami. Every ounce and a half of processed meat eaten a day is thought to increase a person's risks of developing colorectal cancer by 21 percent.

Making better dietary choices

Experts have long believed that eating a diet rich in fiber is good for cancer prevention and good health in general. Aiming for a healthy diet, try to increase your fiber intake to 25 or 30 grams per day, emphasizing wheat bran. Of course, this should be done gradually, since the digestive system needs a little time to adjust to a drastic increase in fiber intake.

Increasing your calcium intake can prevent both colorectal cancer and polyps. One most compelling study found that people who were given regular calcium supplements developed far fewer polyps and reducing polyp growth is probably a good thing for your chances of later developing colorectal cancer. The intimate interplay between vitamin D and the body's calcium metabolism certainly suggests that vitamin D could enhance the good effects of calcium.

Studies suggest that you can reduce your risk of colorectal cancer by 50 or 60% by increasing the amount of folate in your diet. Folate happens to be a very important substance; it is a critical player in the synthesis of both DNA and RNA, the genetic building blocks, as well as other areas of the human metabolism. Therefore, in theory, it is not surprising that lack of folate in the diet leads to serious problems. Since most experts agree that cancer is caused by insufficiently repaired defects in our DNA, it makes sense that inadequate amounts of folate might lead to DNA abnormalities and a greater risk of cancer.

Some research has indicated that taking antioxidants, such as vitamin C or carotenoids, may reduce cancer risk. A diet high in antioxidants is usually also high in vegetables. These kind of diets seem to be protective against colon cancer, though we don't know exactly why or how.

Among all the antioxidants, selenium seems to be the only one that shows real promise in the prevention of colorectal cancer. This is largely based on one study that showed that taking a selenium supplement over a period of several years led to a 25% decline in the incidence of colorectal cancers. People who are concerned about preventing colorectal cancer can take 200 ug of selenium per day. Remember that the safe upper limit of selenium is 400 ug/day.

To sum up, a diet high in fruits and vegetables (5+ servings/day, emphasizing fresh vs. cooked items), high in whole grain fiber and low in red meat and saturated fat is recommended. You can take a multivitamin each day that provides an additional 400 ug of folate and sufficient vitamin D. Finally, it would be reasonable to take a 1200 mg supplement of calcium, as well as a 200 ug supplement of selenium.

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