Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain.
IdiSNA, Navarra Institute for Health Research, Pamplona, Spain.
Cancer Epidemiol Biomarkers Prev. 2021 Oct;30(10):1921-1931. doi: 10.1158/1055-9965.EPI-21-0352. Epub 2021 Jul 21.
Plant-based diets have been associated with lower risk of various diseases, including type 2 diabetes, cardiovascular disease, and other cardiometabolic risk factors. However, the association between plant-based diet quality and breast cancer remains unclear.
We prospectively followed 76,690 women from the Nurses' Health Study (NHS, 1984-2016) and 93,295 women from the NHSII (1991-2017). Adherence to an overall plant-based diet index (PDI), a healthful PDI (hPDI), and an unhealthful PDI (uPDI) was assessed using previously developed indices. Cox proportional hazards models were used to estimate HR and 95% confidence intervals (CI) for incident invasive breast cancer.
Over 4,841,083 person-years of follow-up, we documented 12,482 incident invasive breast cancer cases. Women with greater adherence to PDI and hPDI were at modestly lower risk of breast cancer [(HR, 0.89; 95% CI, 0.84-0.95); (HR, 0.89; 95% CI, 0.83-0.94)]. We observed significant heterogeneity by estrogen receptor (ER) status, with the strongest inverse association between hPDI and breast cancer observed with ER-negative tumors [HR, 0.77; 95% CI, 0.65-0.90; < 0.01]. We also found an inverse association between extreme quintiles of healthy plant foods and ER-negative breast cancer [HR, 0.74; 95% CI, 0.61-0.88; < 0.01].
This study provides evidence that adherence to a healthful plant-based diet may reduce the risk of breast cancer, especially those that are more likely to be aggressive tumors.
This is the first prospective study investigating the relation between healthful and unhealthful plant-based dietary indices and risk of total and subtype-specific breast cancer.
植物性饮食与多种疾病的风险降低有关，包括 2 型糖尿病、心血管疾病和其他心血管代谢危险因素。然而，植物性饮食质量与乳腺癌之间的关联尚不清楚。
我们前瞻性地随访了来自护士健康研究（NHS，1984-2016 年）的 76690 名女性和来自护士健康研究 II 期（NHSII，1991-2017 年）的 93295 名女性。使用先前开发的指数评估整体植物性饮食指数（PDI）、健康 PDI（hPDI）和不健康 PDI（uPDI）的依从性。使用 Cox 比例风险模型估计了事件性浸润性乳腺癌的 HR 和 95%置信区间（CI）。
在超过 4841083 人年的随访期间，我们记录了 12482 例事件性浸润性乳腺癌病例。PDI 和 hPDI 依从性较高的女性患乳腺癌的风险略低[HR，0.89；95%CI，0.84-0.95）；（HR，0.89；95%CI，0.83-0.94）]。我们观察到雌激素受体（ER）状态存在显著的异质性，hPDI 与 ER 阴性肿瘤之间的负相关最强[HR，0.77；95%CI，0.65-0.90；<0.01]。我们还发现健康植物性食物的极端五分位数与 ER 阴性乳腺癌之间存在负相关[HR，0.74；95%CI，0.61-0.88；<0.01]。
这项研究提供了证据表明，遵循健康的植物性饮食可能降低乳腺癌的风险，特别是那些更可能是侵袭性肿瘤的风险。
这是第一项前瞻性研究，调查了健康和不健康的植物性饮食指数与总乳腺癌和亚型特异性乳腺癌风险之间的关系。
