Submitted to: Cancer Epidemiology Biomarkers and Prevention
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2004
Publication Date: 6/6/2004
Citation: Stolzenberg-Solomon, R., Ghormli, L., Schatzkin, A., Rosen, C., Clevidence, B.A., Campbell, W., Snyder, K., Judd, J., Taylor, P. 2004. Effects of a low fat, high fiber-complex carbohydrate diet on components of the igf axis measured in plasma: a controlled feeding study in men. Cancer Epidemiology Biomarkers and Prevention. 13:1086-1087. Interpretive Summary: Studies have suggested that risk of men developing prostate cancer and colorectal cancer may be related to amounts of a specific growth factor (insulin-like growth factor-I, IFG-I) and the protein that binds to this growth factor (IGF binding protein-3). We assessed the levels of these proteins in plasma of men who ate diets of known and very different composition (controlled diets). Each subject ate each diet in random order. The diets were 1.) high in fat and low fiber or 2.) low in fat and high in fiber. Each diet lasted 10 wks. No effect was observed for the binding protein. The low fat, high fiber diet increased IGF-I levels in plasma, but only in those men who ate the low fat, high fiber diet prior to eating the high fat, low fiber diet. This lack of consistency made the data difficult to interpret. However, the study suggested that diet may influence factors related to prostate and colorectal cancer in men and thus warrant further investigation. These results are of interest to scientists who specialize in diet and cancer.
Technical Abstract: Higher concentrations of plasma insulin-like growth factor-I (IGF-I) and lower concentrations of IGF binding protein-3 (IGFBP-3) have been associated with increased risk of prostate cancer and colorectal cancer in men. Although dietary factors may influence concentrations of these proteins in plasma, few studies have evaluated the response of these factors to diet. We examined the effect of two dietary patterns on the IGF-I axis in a crossover feeding study. Subjects were men who consumed an experimental diet (low fat, high fiber) or a control diet (high fat, low fiber) for 10 wks. Compared with the control diet, the experimental diet appeared to significantly increase IGF-I levels. No overall effect was seen for the IGFBP-3 or the IGF-I to IGFBP-3 ratio. However, the interpretation of the study is limited due to a carryover effect such that higher concentrations of IGF-I with the experimental diet were observed only among men who consumed the experimental diet first and the control diet second. The inconsistencies with respect to the feeding order and period make interpretation problematic.