Bogen K T, Keating G A, Chan J M, Paine L J, Simms E L, Nelson D O, Holly E A
Lawrence Livermore National Laboratory, Energy and Environment Directorate, University of California, 7000 East Avenue, Livermore, CA 94550, USA.
Prostate Cancer Prostatic Dis. 2007;10(3):261-9. doi: 10.1038/sj.pcan.4500941. Epub 2007 Jan 16.
African-American men die from prostate cancer (PC) nearly twice as often as white US men and consume about twice as much of the predominant US dietary heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a genotoxic rat-prostate carcinogen found primarily in well-cooked chicken and beef. To investigate the hypothesis that PhIP exposure increases PC risk, an ongoing prospective clinic-based study compared PC screening outcomes with survey-based estimates of dietary PhIP intake among 40-70-year-old African-American men with no prior PC in Oakland, CA. They completed food-frequency and meat-cooking/consumption questionnaires and had a prostate-specific antigen (PSA) test and digital-rectal exam. Results for 392 men indicated a 17 (+/-17) ng/kg day mean (+/-1 s.d.) daily intake of PhIP, about twice that of white US men of similar age. PhIP intake was attributable mostly to chicken (61%) and positively associated (R(2)=0.32, P<0.0001) with saturated fat intake. An odds ratio (95% confidence interval) of 31 (3.1-690) for highly elevated PSA > or =20 ng/ml was observed in the highest 15% vs lowest 50% of estimated daily PhIP intake (> or =30 vs < or =10 ng/kg day) among men 50+ years old (P=0.0002 for trend) and remained significant after adjustment for self-reported family history of (brother or father) PC, saturated fat intake and total energy intake. PSA measures were higher in African-American men with positive family history (P=0.007 all men, P<0.0001 highest PSA quartile). These preliminary results are consistent with a positive association between PhIP intake and highly elevated PSA, supporting the hypothesis that dietary intervention may help reduce PC risk.
非裔美国男性死于前列腺癌（PC）的几率几乎是美国白人男性的两倍，并且摄入的美国主要膳食杂环胺——2-氨基-1-甲基-6-苯基咪唑并[4,5-b]吡啶（PhIP）约为白人男性的两倍。PhIP是一种具有基因毒性的大鼠前列腺致癌物，主要存在于烹饪熟透的鸡肉和牛肉中。为了研究PhIP暴露会增加前列腺癌风险这一假说，一项正在进行的基于临床的前瞻性研究，比较了加利福尼亚州奥克兰市40至70岁且无前列腺癌病史的非裔美国男性的前列腺癌筛查结果与基于调查的膳食PhIP摄入量估计值。他们完成了食物频率和肉类烹饪/消费调查问卷，并进行了前列腺特异性抗原（PSA）检测和直肠指检。392名男性的结果显示，PhIP的日均摄入量为17（±17）纳克/千克·天（±1个标准差），约为年龄相仿的美国白人男性的两倍。PhIP的摄入量主要归因于鸡肉（61%），并且与饱和脂肪摄入量呈正相关（R² = 0.32，P < 0.0001）。在50岁及以上男性中，估计每日PhIP摄入量最高的15%人群与最低的50%人群（≥30 vs ≤10纳克/千克·天）相比，PSA高度升高（≥20纳克/毫升）的优势比（95%置信区间）为31（3.1 - 690）（趋势P = 0.0002），在调整了自我报告的（兄弟或父亲）前列腺癌家族史、饱和脂肪摄入量和总能量摄入量后，该结果仍然显著。有前列腺癌家族史的非裔美国男性的PSA测量值更高（所有男性P = 0.007，PSA最高四分位数P < 0.0001）。这些初步结果与PhIP摄入量和PSA高度升高之间的正相关一致，支持了膳食干预可能有助于降低前列腺癌风险这一假说。
