Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.
Cancer Causes Control. 2011 Jan;22(1):51-61. doi: 10.1007/s10552-010-9671-x. Epub 2010 Oct 31.
Insulin may play a role in prostate cancer tumorigenesis. Postprandial blood glucose and insulin responses of foods depend importantly on the carbohydrate quality and quantity, represented by glycemic index (GI), glycemic load (GL), fiber and whole-grain content, but are also influenced by intake of protein and other characteristics. The recently developed insulin index (II) quantifies the postprandial insulin secretion, also taking into account these additional characteristics.
We investigated the association between dietary GI, GL, II, fiber, and whole grains and risk of total prostate cancer (n = 5,112) and subgroups of prostate cancer as defined by stage or grade in 49,934 male participants of the Health Professionals Follow-up Study. Multivariate adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression.
Dietary GI, GL, II, or fiber was not associated with risk of total or subgroups of prostate cancer. We observed a positive association between dietary intake of whole grains and total prostate cancer (HR highest versus lowest quintile 1.13, 95% CI 1.03-1.24), which was attenuated after restriction to PSA-screened participants (HR 1.03, 95% CI 0.91-1.17).
These results suggest that long-term exposure to a diet with a high insulin response does not affect prostate cancer incidence.
胰岛素可能在前列腺癌的发生中起作用。食物的餐后血糖和胰岛素反应主要取决于碳水化合物的质量和数量，由血糖指数（GI）、血糖负荷（GL）、纤维和全谷物含量来表示，但也受到蛋白质和其他特征的摄入的影响。最近开发的胰岛素指数（II）量化了餐后胰岛素分泌，同时也考虑了这些额外的特征。
我们研究了饮食 GI、GL、II、纤维和全谷物与总前列腺癌（n=5112）以及 49934 名男性健康专业人员随访研究参与者中根据分期或分级定义的前列腺癌亚组风险之间的关联。使用 Cox 比例风险回归估计多变量调整后的危险比（HR）和 95%置信区间（95%CI）。
饮食 GI、GL、II 或纤维与总前列腺癌或前列腺癌亚组的风险无关。我们观察到全谷物饮食摄入量与总前列腺癌呈正相关（最高五分位与最低五分位之比为 1.13，95%CI 1.03-1.24），在限制于 PSA 筛查参与者后，这种相关性减弱（HR 1.03，95%CI 0.91-1.17）。
这些结果表明，长期暴露于高胰岛素反应的饮食不会影响前列腺癌的发病率。
