Colorectal cancer

Scientific studies (review articles) on the relationship between diet/nutrients and colorectal cancer prevention:
One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of randomized, placebo-controlled double blind clinical trials (RCTs) will answer the following question:
"Do taking dietary supplements make sense?" Yes for a positive conclusion and no for a negative conclusion.

One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of (prospective) cohort studies or case-control studies will answer the following question:
"Should I change my diet?".

1. Higher blood levels of alpha-linolenic acid reduce colorectal cancer
2. Postoperative coffee or caffeine consumption causally reduces postoperative ileus
3. High consumption of dietary trans fat increases prostate cancer and colorectal cancer
4. Post-diagnosis calcium, vitamin C, D or E decreases cancer mortality
5. Tea consumption may reduce colorectal cancer in female
6. High consumption of cruciferous vegetables, citrus fruits, garlic and tomatoes may reduce colorectal cancer
7. Garlic could reduce risk of colorectal cancer
8. Wine consumption is not associated with colorectal cancer
9. High intake of dietary flavonols, flavones and anthocyanidins may decrease colorectal cancer
10. Daily dietary intake of 100g red meat and 50g processed meat increase risk of colorectal cancer
11. Dietary calcium intake reduces colorectal adenomas
12. At least 1600 mg/day calcium may reduce the recurrence of colorectal adenomas
13. 5 mg/day vitamin B2 intake reduces colorectal cancer risk
14. High blood vitamin B6 levels reduce colorectal cancer
15. High dietary vitamin B9, D, B6 and B2 intake reduces risk of colorectal cancer
16. Higher dietary carbohydrate intake increases colorectal cancer risk in men
17. 20 mg/d isoflavones dieatary intake reduces risk of colorectal neoplasms in Asians
18. Cruciferous vegetable intake protects against cancer of the colon

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Colon cancer is cancer of the large intestine (colon), the lower part of the digestive system. Rectal cancer is cancer of the last several inches of the colon. Together, they are often referred to as colorectal cancer.

Most cases of colorectal cancer begin as small, noncancerous (benign) clumps of cells called adenomatous polyps. Over time some of these polyps become colorectal cancer.

You have a high risk of colorectal cancer if you:

• are older than 50. Although the average person has a 5% lifetime risk of developing colorectal cancer, 90% of these cancers occur in people older than 50 years of age.
• are African American of eastern European descent.
• eat a lot of red or processed meats.
• smoke or drink.
• have colorectal polyps.
• have inflammatory bowel disease (Crohn's disease or ulcerative colitis).
• have a family history of colorectal cancer.
• have a personal history of breast cancer.

Certain inherited diseases also increase risk of developing colorectal cancer. Two of the most common are:

• familial adenomatous polyposis (FAP).
• hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome.

Stages of colorectal cancer are:

• stage 0: Very early cancer on the innermost layer of the intestine.
• stage I: Cancer is in the inner layers of the colon.
• stage II: Cancer has spread through the muscle wall of the colon.
• stage III: Cancer has spread to the lymph nodes.
• stage IV: Cancer has spread to other organs outside the colon.

The primary goal of colorectal cancer screening is to prevent deaths from colorectal cancer. Screening tests can help identify cancers at an early and potentially treatable stage. There are several ways to screen for colorectal cancer:

• stool test. Only 2 to 5% of people with a positive stool test actually have colorectal cancer. If the stool test is positive, your entire colon should be examined with colonoscopy.
• sigmoidoscopy.
• colonoscopy.

Both men and women should have a colorectal cancer screening test starting at age 50. Some health care providers recommend that African Americans begin screening at age 45.