Glycemic index, glycemic load and risk of prostate cancer

Abstract

Dietary carbohydrates have different glycemic and insulinemic potentials depending on type (glycemic index, GI) and amount (glycemic load, GL) of carbohydrate consumed or both. Insulin in turn has been implicated as a risk factor for several cancers, including that of the prostate. We assessed the relationship of GI and GL with prostate cancer risk in a multicenter case-control study. Dietary factors associated with a Western lifestyle, such as high intakes of refined carbohydrates, fat, meat, dairy foods and excess energy, as well as lack of physical activity have been shown to increase prostate cancer risk. 1-5 A Western lifestyle is also associated with insulin resistance, which in turn has been linked to higher prostate cancer risk. 6 Dietary carbohydrates have different potentials to raise blood glucose and insulin levels and, hence, to modulate insulin sensitivity.The physiologic classification of carbohydrate foods based on postprandial blood glucose response is defined as the GI, a measure of carbohydrate quality (e.g., fast vs. slowly absorbable carbohydrates). 7 Derived from the GI is the GL, which represents quality and quantity of carbohydrate foods. The GI and GL of the diet are emerging risk factors for cancer, which have attracted attention following the association of the metabolic syndrome with the process of carcinogenesis. 6,8 -16 It has been proposed that low GI foods, by virtue of their slower rate of intestinal absorption, and insulin economy (reduced insulin levels) for a given carbohydrate load 17,18 may reduce the risk of insulin-related diseases including cancer. 13 The IGF system, which is also dependent on insulin levels, and in particular high levels of IGF-I, has been related to excess prostate cancer risk. 19 -22 However, no studies have yet looked at the association between prostate cancer risk and types of dietary carbohydrate using their physiologic classification. We therefore investigated the association of dietary GI and GL with prostate cancer risk in a casecontrol study conducted in Italy. MATERIAL AND METHODSA multicenter case-control study of prostate cancer was conducted in Italy between 1991 and 2002. 23 Cases were 1,204 men (median age 66, range 46 -74 years) admitted with incident, histologically confirmed prostate cancer to the major teaching and general hospitals in the greater Milan area, the provinces of Pordenone and Gorizia in northern Italy, the province of Latina in central Italy and the urban area of Naples in southern Italy. Among cases, 39% were diagnosed because of symptoms, 23% through screening and 16% accidentally. For 22% of cases there was no information on type of diagnosis. Histologic grade (Gleason score) was 2-6 for 41% of cases, Ն7 for 30% of cases and unknown for the other 29%. Controls were 1,352 men (median age 63, range 46 -74 years) admitted to the same network of hospitals as cases for acute, nonmalignant conditions unrelated to long-term modifications of diet. Among controls, 33% had nontraumatic orthopedic disorders, 21% trauma, 17% s...

Carbohydrate restriction, prostate cancer growth, and the insulin‐like growth factor axis

“…Indeed, two recent human studies have suggested that either a highstarch diet [14] or a high glycemic index diet [15] increases prostate cancer risk. These observations seem plausible given that a high carbohydrate diet stimulates insulin production and insulin is a known prostate cancer growth factor [7].…”

“…This raises the interesting possibility that carbohydrate restriction, via lowered insulin levels and perhaps lower IGF-1 levels [13] may delay prostate cancer growth. Indeed, a limited number of human studies suggest that carbohydrate intake may influence prostate cancer biology to a greater extent than fat intake [14,15].…”

Methodology for adding glycemic index and glycemic load values to 24-hour dietary recall database

“…The concept of the glycemic index (GI) has provided the scientific community with a new way to examine the quality of carbohydrate (CHO), which has been useful in research on the etiology and prevention of diabetes, coronary heart disease, obesity, prostate cancer, and other chronic diseases [1][2][3][4][5][6]. Historically, CHOs have been classified into two major forms: complex and simple.…”

Dose-Dependent Inhibition of the Post-Prandial Glycaemic Response to a Standard Carbohydrate Meal following Incorporation of Alpha-Cyclodextrin

“…Recent studies have indicated that post-prandial elevations in blood glucose concentrations are a signifi cant risk factor for the development of diabetes, cardiovascular disease and certain cancers [1][2][3][4][5] . In contrast, diets based on foods which produce lower post-prandial blood glucose responses (i.e.…”