Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA.
Department of Academic Research, Saint Joseph Mercy Hospital, Ann Arbor, MI.
Int J Cancer. 2018 Jun 1;142(11):2207-2214. doi: 10.1002/ijc.31247. Epub 2018 Jan 23.
Several meta-analyses have attempted to determine the relationships between intake of α-linolenic acid (ALA) and prostate cancer, but results were inconclusive. 47,885 men aged 40-75 years without prior cancer in the Health Professionals Follow-Up Study were prospectively followed from 1986 to 2010. Intake of ALA was determined from validated food frequency questionnaires every 4 years. We used multivariate Cox proportional hazards models to estimate hazard ratios (HR) with 95% confidence intervals (CIs) for lethal prostate cancer (distant metastasis or prostate cancer death). 386 lethal prostate cancers were diagnosed in the pre-PSA era (before February, 1994) and 403 cancers in the PSA era. Intake of ALA was associated with increased risk of lethal prostate cancer in the pre-PSA era (comparing top to bottom quintile of intake, multivariate-adjusted HR = 1.78; 95% CI = 1.22-2.06; p = 0.003), but not in the PSA era (HR = 0.81; 95% CI = 0.56-1.17; p = 0.53), and the difference in associations was statistically significant (p for interaction = 0.02). Mayonnaise, a primary food source of ALA intake in our cohort, was likewise only significantly associated with lethal prostate cancer in the pre-PSA era. Among many other fatty acids that are correlated with ALA due to shared food sources, none was associated with lethal prostate cancer in the pre-PSA era. In conclusion, higher intake of ALA was associated with an increased risk of lethal prostate cancer in the pre-PSA era, but not in the PSA era. Potential reasons for the differential associations warrant further investigation.
几项荟萃分析试图确定 α-亚麻酸（ALA）的摄入量与前列腺癌之间的关系，但结果尚无定论。1986 年至 2010 年，前瞻性随访了健康专业人员随访研究中年龄在 40-75 岁且无既往癌症的 47885 名男性。ALA 的摄入量是通过每 4 年进行一次的验证后的食物频率问卷来确定的。我们使用多变量 Cox 比例风险模型来估计危险比（HR）和 95%置信区间（CI），用于致命性前列腺癌（远处转移或前列腺癌死亡）。在 PSA 时代（1994 年 2 月之前）诊断出 386 例致命性前列腺癌，在 PSA 时代诊断出 403 例。在 PSA 时代之前，ALA 的摄入量与致命性前列腺癌的风险增加相关（与摄入量最高和最低五分位数相比，多变量调整后的 HR=1.78；95%CI=1.22-2.06；p=0.003），但在 PSA 时代不相关（HR=0.81；95%CI=0.56-1.17；p=0.53），而且关联的差异具有统计学意义（p 交互作用=0.02）。蛋黄酱是我们队列中 ALA 摄入量的主要食物来源，仅在 PSA 时代之前与致命性前列腺癌显著相关。在由于共同食物来源而与 ALA 相关的许多其他脂肪酸中，没有一种与 PSA 时代之前的致命性前列腺癌相关。总之，ALA 摄入量较高与 PSA 时代之前致命性前列腺癌的风险增加相关，但与 PSA 时代不相关。差异关联的潜在原因值得进一步研究。
