New evidence shows selenium and omega-3s prevent colon cancer

Monday, January 25, 2010 by: S. L. Baker, features writer
Tags: colorectal cancer, selenium, health news

(NaturalNews) When scientists gathered in Houston recently for the American Association for Cancer Research (AACR) Frontiers in Cancer Prevention Research Conference, they heard groundbreaking evidence about how colon cancer can be prevented. The new data wasn't about drugs or surgery, either. Instead, two separate research groups concluded natural substances appear to protect from often deadly colon malignancies.

Colon cancer, which the American Cancer Society estimates is diagnosed in over 108,000 Americans each year, is intricately linked to adenomas, also called polyps. These lesions grow in the large bowel and start off as benign. However, they can turn into cancerous tumors and 70 to 80% of all cancers of the colon (the longest part of the large intestine) and rectum result from adenomas-turned-malignant.

So, in hopes of preventing future cancerous growths, polyps found during colonoscopies are snipped off and biopsied. Unfortunately though, pre-cancerous polyps often return. But scientists at the National Institute for Cancer Research in Genoa, Italy, conducted a long term study that shows the risk of pre-cancerous polyps (dubbed colorectal metachronous adenomas) coming back after they've been removed can be greatly reduced. The key? Taking specific antioxidants, including a selenium-based compound.

"Our study is the first intervention trial specifically designed to evaluate the efficacy of the selenium-based antioxidant compound on the risk of developing metachronous adenomas," said Luigina Bonelli, M.D., head of the unit of secondary prevention and screening at the National Institute for Cancer Research, in a statement to the media.

40% reduced risk

The research team studied volunteers between the ages of 25 and 75 who had already had one or more colorectal adenomas removed. None of the participants were diagnosed with any additional colorectal disease, cancer or other life-threatening illness and none were taking vitamins or mineral supplements when the study began. The scientists randomly divided the 411 participants into two groups: those in one group received an inactive placebo and those in the second group took a daily antioxidant supplement containing a selenium compound (selenomethionnine 200 ug), zinc 30 mg, vitamin A 6,000 IU, vitamin C 180 mg and vitamin E 30 mg.

"Our results indicated that individuals who consumed antioxidants had a 40% reduction in the incidence of metachronous adenomas of the large bowel," Bonelli said. "It is noteworthy that the benefit observed after the conclusion of the trial persisted through 13 years of follow up."

Omega-3s help prevent colorectal cancer

Another study just released at the Frontiers in Cancer Prevention Research Conference -- this one from the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina -- found that omega-3 fatty acids, which are primarily found in cold water fish such as salmon, may be able to prevent colorectal cancer.

The scientists recruited 1,509 Caucasian participants (716 cancer cases and 787 controls) and 369 African-American participants (213 cancer cases and 156 controls). A validated food questionnaire was used to collect information on the frequency and amount of foods typically consumed by the research subjects in the past 12 months. Those who ate more long-chain omega-3 fatty acids had a significantly reduced risk of large bowel cancer. In fact, the highest intake was linked to an almost 40% decreased cancer risk. Unfortunately, the greatly reduced risk was only seen in white research subjects and the scientists are trying to figure out what might account for the racial disparity.

"Experimental data have shown benefits of long-chain omega-3 fatty acids in colorectal carcinogenesis, ranging from reduced tumor growth, suppression of angiogenesis and inhibition of metastasis," research leader Sangmi Kim, Ph.D., said in a statement to the press. "Our finding of inverse association between dietary intakes of long-chain omega-3 fatty acids and distal large bowel cancer in white participants adds additional support to the hypothesis."

These new studies linking natural substances to colon cancer prevention are part of a growing body of evidence indicating dietary measures can fight this kind of cancer successfully. For example, as NaturalNews has previously reported, the disease is primarily linked to the typical Western diet (https://www.naturalnews.com/025974_cancer_hea...), so avoiding processed food and trans fats (https://www.naturalnews.com/025880_trans_fat_...) can go far to prevent it. What's more, blueberries have been shown to slash the risk of colon cancer by 57% (https://www.naturalnews.com/021951_blueberrie...) and apples contain natural phytochemicals that have a protective effect against colon cancer (https://www.naturalnews.com/023136_cancer_app...), too.

For more information:
http://www.aacr.org/home/public--media/aacr-...
http://www.aacr.org/home/public--media/aacr-...
http://www.cancer.gov/cancertopics/types/col...