On September 1, 2010, Dr. Mehmet Oz disclosed that he was found adenomatous polyp in a colonoscopy as he turned 50 years. Adenomatous polyp of the colon has the potential of becoming cancer. [1] Many people were shocked with this news, because they would think the doctor should not get sick, at least not from the disease, which the doctor try to help his patients prevent. When the doctor falls victim to the disease, how can his patients continue to trust and follow his advice? Nonetheless, the author sincerely wishes Dr. Oz the best and hope that his polyp will never become malignant.
Dr. Oz has been well known for his writings and TV shows on diet and health. His young and handsome appearance have helped convince his readership and audience that following his diet plan would lead them a life of good health. His diet plan advocates low in both calorie and fat and high in carbohydrate including vegetables and whole grains, but shunning sugar. He insists cutting 100 calories a day but no need of counting carbohydrates. [2] This diet plan is that described in the article, “An Overview of Dieting for Health: The Diets”, Type (2C): Carbohydrate-rich, fat-restricted diet with calorie restriction. Although the dieter with this plan loses weight, the result of his biomarkers varies depending on the amount of carbohydrates he consumes. [3]
Colorectal cancer has increasingly gained attention because of its prevalence and death rate. For 2010 in the US, the estimated new cases will be 102,900 for colon cancer and 39,670 for rectal cancer. The estimated deaths will be 51,370 for colon and rectal cancers combined. [4]
The Journal of American Medical Association, in its January 12, 2005 issue, published two interesting articles, one by Chao A et al, “meat consumption and risk of colorectal cancer”, [5] and the other by Jee SH et al, “fasting serum glucose level and cancer risk in Korean men and women.” [6] The contrast in epidemiological results between the two studies deserves a review on the relationship between carbohydrates and colorectal colon cancer, as today’s medicine has acknowledged and embraced the relationship between the risk of colorectal cancer and the consumption of processed meat.
The 10-year cohort study by Jee et al collected the health data of 1,298,385 Koreans (829,770 men and 468,615 women), aged between 30 and 95 years, found the risks for various cancers were positively related to the individual’s fast serum glucose level and a diagnosis of diabetes mellitus, but did not find a notable link to body mass index. In other words, being slim alone does not reduce the risks for cancers. Although the study covered variable cancers, the colorectal and liver cancers in men were statistically significant in related to the fasting serum glucose (0.03 each) only next to the esophageal (0.007) pancreatic (0.009) cancers. At the same time, the colorectal cancer in women also had a significant trend with the fasting serum glucose level. While the fasting blood serum glucose level is positively linked to the risk of cancers including colorectal cancer, those study participants in the control group, whose fasting serum glucose was below 90 mg%, still yielded a substantial number of incidences. This indicates positive association of the serum glucose level to the risks of cancers might be beyond that of the fasting.
Despite several studies denied the connection between the incidence of colorectal cancer and glycemic index, glycemic load, and carbohydrates consumption, [7, 8] the data from nearly 1.3 million individuals used in Jee’s study can hardly be ignored.
In addition, more recent studies supported the link between the risk of colorectal cancer and the consumption of carbohydrates. [9, 10] Gnagnarella P et al summarized, “This comprehensive meta-analysis of GI and GL and cancer risk suggested an overall direct association with colorectal and endometrial cancer.” [11] Barclay AW et al concluded, “The findings support the hypothesis that higher postprandial glycemia is a universal mechanism for disease progression.” [12]
Several studies have found postprandial hyperglycemia triggers inflammation. [13] A review article by Coussens LM and Werb Z cites, “It is now evident that inflammatory cells have powerful effects on tumour development. Early in the neoplastic process, these cells are powerful tumour promoters, producing an attractive environment for tumour growth, facilitating genomic instability and promoting angiogenesis”, and, “It is clear that anti-inflammatory therapy is efficacious towards early neoplastic progression and malignant conversion. In a fully developed malignancy, there are ‘excess’ inflammatory cells in the tumour microenvironment.” [14] The latter substantiates the observation that the use of Aspirin reduces the deaths from colon cancer.” [15]
Ely JTA. In his 1996 article, cited the relationship between a positive link between hyperglycemia and the incidence of cancers and vice versa, because neoplastic initiations are found and reversed by lymphocytes and monocytes, which functions are inversely related to the glycemic level. [16] In 2005, Ely and Krone CA in a review article suggested that normalizing the glycemic level of cancer patients helps keep remission of their cancers. [17]
Having illustrated the association between hyperglycemia and the risk for colorectal cancer, keeping a normal and stable glycemic level is very critical in cancer prevention, including the colorectal cancer, which is the focus of this article. The higher the consumption of carbohydrates, the higher the postprandial glycemic level will be. Keep in mind; whole grains and starchy foods are sugars too because they are converted into monosaccharides or simple sugars before absorption. [18] Thus, consuming the calorie-restricted, carbohydrate-rich, and fat-restricted diet, as which Dr; Oz has advocated, is likely to increase the risks of cancers including the colon cancer.
Robert Su, Pharm.B., M.D.
References:
1. FOX News. “Dr. Mehmet Oz Has Colon Cancer Scare During Taping of His Show.” FOX Chicago News. September 1, 2010.
2. Dr. OZ “YOU: ON A Diet Basics.”
3. Su RK. “An Overview of Dieting for Health: The Diets”
4. Centers For Disease Control and Prevention. “Colorectal Cancer Statistics.” Colorectal (Colon) Cancer.
5. Chao A. et al “Meat Consumption and Risk of Colorectal Cancer.” Journal of American Medical Association, (JAMA). Volume 293, Number 2, Pages 172-182. January 12, 2005.
6. Jee SH et al. “Fasting serum glucose level and cancer risk in Korean men and women.” Journal of American Medical Association, (JAMA). Volume 293, Number 2, Pages 194-202. January 12, 2005.
7. Terry PD et al, “Glycemic Load, Carbohydrate Intake, and Risk of Colorectal Cancer in Women: A Prospective Cohort Study.” Journal of the National Cancer Institute, Vol. 95, No. 12, 914-916, June 18, 2003.
8. NC Hoaworth et al, “The association of glycemic load and carbohydrate intake with colorectal cancer risk in the Multiethnic Cohort Study.” American Journal of Clinical Nutrition, Vol. 88, No. 4, 1074-1082, October 2008.
9. Michaud DS, et al. “Dietary Glycemic Load, Carbohydrate, Sugar, and Colorectal Cancer Risk in Men and Women.” the Cancer Epidemiology Biomarkers & Prevention Volume 14, Number 1, Pages 138-147, January 2005.
10. Higginbotham S, et al. “Dietary Glycemic Load and Risk of Colorectal Cancer in the Women’s Health Study.” Journal of National Cancer Institute, 2004; 96:229 –33.
11. Gnagnarella P et al, “Glycemic index, glycemic load, and cancer risk: a meta-analysis.” American Journal of Clinical Nutrition, Vol. 87, No. 6, 1793-1801, June 2008.
12. Barclay AW et al, “Glycemic index, glycemic load, and chronic disease risk—a meta-analysis of observational studies.” American Journal of Clinical Nutrition. Vol. 87, Pages 627–37. 2008.
13. Su RK, “Carbohydrates Can Kill: Hyperglycemia is problematic but preventable by restricting carbohydrates. (1 of 3).” The Blog. Carbohydrates Can Kill. August 16, 2010.
14. Coussens LM and Werb Z. “Inflammation and cancer.” Nature. Volume 420, Number 6917, Pages 860-7. December 19-26, 2002.
15. Su RK, “Aspirin Reduces Colon Cancer Deaths.” The Blog. Carbohydrates Can Kill. November 25, 2009.
16. Ely JTA. “Glycemic Modulation of Tumor Tolerance.” Journal of Orthomolecular Medicine, Volume 11, Number 1, Pages 23-34. 1996.
17. Krone CA and Ely JTA. “Controlling Hyperglycemia as an Adjunct to Cancer Therapy.” Integrated Cancer Therapies, Volume 4, Number 1, Pages 25-31. 2005.
18. Su RK. “Figure 2: Digestion and Absorption of Carbohydrates.” Chapter 1 Nutrition 101. The Digestions of Different Nutrients. Carbohydrates Can Kill. Page 9-10
