Vitamins and minerals found naturally in foods contain powerful phytochemicals. These substances have antioxidant properties and have consistently been linked to offering valuable protection against diseases like cancer.

Two separate studies have now concluded that the mineral selenium and omega-3 fatty acids provide natural protection against colon cancer.

Colon cancer is also known as bowel cancer. The colon is where the body stores waste material and is part of the digestive system. Growths that form on the colon, bowel or rectum usually start off as benign (non-cancerous) but can sometimes become cancerous. These are called polyps. It is thought that most cases of colon cancer will have formed and developed from untreated polyps.

Mineral selenium Reduces Colorectal Tumors

Research found that supplementation with a selenium-based antioxidant compound decreased the risk of developing new polyps of the large bowel - called colorectal metachronous adenomas - in people who previously had colorectal polyps removed.

This was the first trial that looked specifically at the antioxidant compound selenium and colon cancer prevention. The findings were presented at the American Association for cancer Research Frontiers in cancer Prevention Research Conference held in December 2009.

Researchers found that taking a five-year selenium-based antioxidant compound supplementation was beneficial, and that supplementation reduced recurrence of colorectal adenomas by 40 percent.

Adenomatous polyps (or adenoma) are benign lesions of the large bowel that could progress to cancer, and are common in people aged 60 years or older; one in four people will have at least one adenoma.

Participants in this study were aged 25 to 75 years and had already had one or more colorectal adenomas removed, but did not have any other diagnosis of colorectal diseases, cancer or life-threatening illnesses and did not use vitamins or calcium supplementations.

The researchers assigned 411 participants to the placebo group or to receive an antioxidant compound - specifically selenomethionnine 200 ¼g, zinc 30 mg, Vitamin A 6,000 IU, Vitamin C 180 mg and Vitamin E 30 mg.

One of the researchers explained:

"Our results indicated that individuals who consumed antioxidants had a 40 percent reduction in the incidence of metachronous adenomas of the large bowel,"

"It is noteworthy that the benefit observed after the conclusion of the trial persisted through 13 years of follow up."

Omega-3 fatty acids Reduce Risk of colon cancer

The second study found that long-chain omega-3 fatty acids, primarily found in fish and seafood, were associated with colorectal cancer prevention, according to results again presented at the American Association for cancer Research Frontiers in cancer Prevention Research Conference, held Dec. 2009. They found that patients who consumed more long-chain omega-3 fatty acids had a 39 percent reduced risk of bowel cancer.

One of the researchers explained:

"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,"

"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."

They studied the link between polyunsaturated fatty acid intake and large bowel cancer in 1,509 white participants (716 cancer cases and 787 controls) and 369 black participants (213 cancer cases and 156 controls).

The researchers collected information on the frequency and amount of foods typically consumed by the participants in the past 12 months, and concluded:

"An increase in dietary intake of long-chain omega-3 fatty acids, which mainly come from fish and seafood, may be beneficial in the prevention of distal large bowel cancer."