Robert Su, Pharm. B., M.D.
Extracts:
Studying the impact of foods on health has been very difficult. Gathering the dietary information from individuals based on their recollection is not totally reliable. The design of a study, such as the selection of participants and the criteria for the control group and test group(s), may significantly affect its result(s) and conclusion.
Despite that studies have claimed various factors, including fat, infection, inflammation, and others, are carcinogenic, some recent studies have linked carbohydrates to the development of different cancers. Some of the linkages might not be strongly positive. However, the vague linkages are worth taking another look at the causal role of carbohydrates in developing cancers. [4]
........study assigned the hazard ratio (HR) of all cancers for the control group at 1.0, whose fasting blood glucose level was 90 mg% or less, but still had 848 cases of cancer deaths. The study also found much higher risks of various cancers for diabetic patients. Based on these two findings, the increase of fasting serum glucose might not be the contributing factor for the increase of risks of cancers.
Rather, the ability of the pancreatic beta cells to produce adequate amount of insulin for lowering the postprandial glycemic level to the normal range might be the contributing factor. Thus, the excursion of the postprandial glycemia in relation to the risks of cancers deserves a careful revisit.
Meinhold CL et al in their May 7, 2010 article, “Available Carbohydrates, Glycemic Load, and Pancreatic Cancer: Is There a Link?” found positive associations between the risk of pancreatic cancer and glycemic load, available carbohydrates, and the consumption of sucrose. [7]
In a study, published on July 20, 2010, by Liu H et al, “Fructose Induces Transketolase Flux to Promote Pancreatic Cancer Growth”, reported fructose, along with glucose, was linked to higher deaths from pancreatic cancer. In particular, fructose speeds up the proliferation of pancreatic cancer. [8]
In the article, by Chautenoud L et al., “Refined-cereal intake and risk of selected cancers in Italy”, published in December 1999, investigated the potential association between the frequency of consuming a starch-rich diet and refined cereals (bread, pasta, or rice) and the risk of selected neoplasms. [9] In comparing the risks for each type of cancers with the group who consumed the least refined cereal, the highest group had an increased risk of 60% for oral cavity, pharynx, esophagus or larynx cancers, 50% for stomach cancer, 50% for colon cancer, 30% for rectal cancer, and 100% for thyroid cancer, respectively.
In “Dietary Glycemic Index, Glycemic Load and Ovarian Cancer Risk: a case–control study in Italy”, Augustin et al uncluded 1,031 women who were diagnosed histologically with epithelial ovarian cancer from four Italian regions, between January 1992 and September 1999. ......the risk of ovarian cancer was increased 65% for the participants whose dietary glycemic index was only nearly 8% higher, in comparison with those participants whose dietary glycemic index was the lowest of this study. Similarly, the risk was increased 65% for those participants whose glycemic load was 87 units or more than that of those participants whose glycemic load was the lowest. The study authors suspected that hyperinsulinemia or insulin resistance might have a role in ovarian cancer development.
Most carbohydrate-restrict dieters consume foods with glycemic index lower than 50 and glycemic load less than 100 units.
References:
1. Su RK “Carbohydrates and Cancers” Carbohydrates Can Kill: Table of Contents. Pages 312-324.2. Su RK “Reading List: Cancer (889-1061)” Reading List To Carbohydrates Can Kill.
3. Holmes MD et al. “Dietary Carbohydrates, Fiber, and Breast Cancer Risk.” American Journal of Epidemiology. 2004, Volume 159, Issue 8, Pages 732-739.
4. George SM et al. “Dietary Glycemic Index, Glycemic Load, and Risk of Cancer: A Prospective Cohort Study.” American Journal of Epidemiology Vol. 169, No. 4 December 18, 2008
5. Su RK “Carbohydrates and Cancer: The Fact.” The Blog. Carbohydrates Can Kill. October 25, 2010.
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. Meinhold CL et al “Available Carbohydrates, Glycemic Load, and Pancreatic Cancer: Is There a Link?” American Journal of Epidemiology. Volume 171, Issue 11, Pages 1174-1182. May 7, 2010.
8. Liu H et al. “Fructose Induces Transketolase Flux to Promote Pancreatic Cancer Growth.” Journal of Cancer Research. July 20, 2010.
9. Chatenoud L. et al. “Refined-cereal intake and risk of selected cancers in Italy.”American Journal of Clinical Nutrition, Vol. 70, No. 6, 1107-1110, December 1999.
10. Augustin et al. “Dietary Glycemic Index, Glycemic Load and Ovarian Cancer Risk: a case–control study in Italy.” Annals of Oncology 14: 78–84, 2003
