Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts.
Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan.
Cancer Prev Res (Phila). 2020 Jan;13(1):65-72. doi: 10.1158/1940-6207.CAPR-19-0297. Epub 2019 Nov 7.
Branched-chain amino acids (BCAA) are essential amino acids, and emerging evidence suggests that BCAAs may mediate pathways related to cancer progression, possibly due to their involvement in insulin metabolism. We investigated the association between dietary intake of BCAAs with colorectal cancer risk in three prospective cohorts: the Nurses' Health Study I [(NHS), number of participants () at baseline = 77,017], NHS II ( = 92,984), and the Health Professionals Follow-up Study [(HPFS) = 47,255]. Validated food frequency questionnaires were administered every 4 years and follow-up questionnaires on lifestyle biennially. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards regression models. Pooled HRs were obtained using random effect models. After up to 28 years of follow-up, 1,660 cases were observed in NHS, 306 in NHS II, and 1,343 in HPFS. In multivariable adjusted models, we observed a weak inverse association between BCAA intake and colorectal cancer [highest vs. lowest quintile, pooled HR including all three cohorts (95% CI): 0.89 (0.80-1.00), = 0.06, HR per standard deviation (SD) increment 0.95 (0.92-0.99)]. However, after including dairy calcium to the models, BCAA intake was no longer associated with risk of colorectal cancer [HR 0.96 (0.85-1.08), = 0.50, HR per SD increment 0.97 (0.93-1.01)]. We did not find evidence that higher dietary BCAA intake is associated with higher risk of colorectal cancer. As this is the first prospective study to examine the association between BCAA intake and colorectal cancer, our findings warrant investigation in other cohorts.
支链氨基酸（BCAA）是必需氨基酸，新出现的证据表明，BCAA 可能介导与癌症进展相关的途径，这可能是由于它们参与胰岛素代谢。我们在三个前瞻性队列中研究了膳食 BCAA 摄入量与结直肠癌风险之间的关联：护士健康研究 I（NHS）[（NHS），基线参与者人数（）= 77017]，NHS II（= 92984）和健康专业人员随访研究[（HPFS）= 47255]。每 4 年进行一次验证后的食物频率问卷，并每两年进行一次生活方式随访问卷。使用 Cox 比例风险回归模型计算危险比（HR）和 95%置信区间（CI）。使用随机效应模型获得汇总 HR。在长达 28 年的随访后，NHS 中观察到 1660 例病例，NHS II 中观察到 306 例，HPFS 中观察到 1343 例。在多变量调整模型中，我们观察到 BCAA 摄入量与结直肠癌之间存在弱负相关[最高与最低五分位组，包括所有三个队列的汇总 HR（95%CI）：0.89（0.80-1.00），= 0.06，HR 每标准差（SD）增加 0.95（0.92-0.99）]。然而，在将乳制品钙纳入模型后，BCAA 摄入量与结直肠癌风险不再相关[HR 0.96（0.85-1.08），= 0.50，HR 每 SD 增加 0.97（0.93-1.01）]。我们没有发现证据表明，较高的膳食 BCAA 摄入量与结直肠癌风险增加相关。由于这是第一项研究 BCAA 摄入量与结直肠癌之间关联的前瞻性研究，我们的发现需要在其他队列中进行调查。
