Willett W C, Hunter D J, Stampfer M J, Colditz G, Manson J E, Spiegelman D, Rosner B, Hennekens C H, Speizer F E
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02215.
JAMA. 1992 Oct 21;268(15):2037-44.
To address the hypotheses that dietary fat increases and fiber decreases the risk of breast cancer.
Prospective cohort study with dietary assessment at baseline, using a validated, self-administered food frequency questionnaire.
SETTING/PARTICIPANTS: 89,494 women in the Nurses' Health Study who were 34 through 59 years of age in 1980 and who were followed up for 8 years (> 95% complete).
1439 incident cases of breast cancer were diagnosed, including 774 among postmenopausal women. After adjustment for age, established risk factors, and total energy intake, we observed no evidence of any positive association between total fat intake and breast cancer incidence (relative risks [RRs] for increasing quintiles of fat intake were 1.0, 0.85, 0.96, 0.91, and 0.90; 95% confidence interval for highest vs lowest quintile, 0.77 to 1.07). Among postmenopausal women alone, corresponding RRs were 1.0, 0.89, 1.00, 0.95, and 0.91. Comparing extreme deciles of total fat intake (> or = 49% vs < 29% of total energy intake), the RR was 0.86 (95% confidence interval, 0.67 to 1.08). A similar absence of any positive association was observed without adjustment for energy intake; for tumors less than 2 cm as well as 2 cm or greater in diameter; for saturated, monounsaturated, and polyunsaturated fat; and after excluding the first 4 years of follow-up. Also, we found no suggestion of any positive association when using a more detailed and precise dietary questionnaire completed in 1984 (666 subsequent cases), even when women consuming less than 25% of energy from fat were used as the comparison group. No suggestion of a protective effect of dietary fiber was observed (RRs for increasing quintiles were 1.0, 0.95, 0.93, 1.02, and 1.02).
These data provide evidence against both an adverse influence of fat intake and a protective effect of fiber consumption by middle-aged women on breast cancer incidence over 8 years. Nevertheless, the positive association between intake of animal fat and risk of colon cancer observed in many studies provides ample reason to limit this source of energy.
验证膳食脂肪会增加、膳食纤维会降低患乳腺癌风险的假设。
前瞻性队列研究，在基线时进行膳食评估，采用经过验证的自填式食物频率问卷。
地点/参与者：护士健康研究中的89494名女性，她们在1980年年龄为34至59岁，随访8年（随访完整率>95%）。
确诊1439例乳腺癌病例，其中绝经后女性774例。在对年龄、已确定的风险因素和总能量摄入进行调整后，我们未发现总脂肪摄入量与乳腺癌发病率之间存在任何正相关的证据（脂肪摄入量增加的五个五分位数的相对风险[RRs]分别为1.0、0.85、0.96、0.91和0.90；最高五分位数与最低五分位数的95%置信区间为0.77至1.07）。仅在绝经后女性中，相应的RRs分别为1.0、0.89、1.00、0.95和0.91。比较总脂肪摄入量的极端十分位数（总能量摄入≥49%与<29%），RR为0.86（95%置信区间为0.67至1.08）。在未对能量摄入进行调整时；对于直径小于2 cm以及直径为2 cm或更大的肿瘤；对于饱和脂肪、单不饱和脂肪和多不饱和脂肪；以及在排除随访的前4年后，也观察到不存在任何正相关。此外，当使用1984年填写的更详细、精确的膳食问卷（后续有666例病例）时，即使将脂肪能量摄入低于25%的女性作为对照组，我们也未发现任何正相关的迹象。未观察到膳食纤维有保护作用的迹象（摄入量增加的五个五分位数的RRs分别为1.0、0.95、0.93、1.02和1.02）。
这些数据表明，中年女性的脂肪摄入量对乳腺癌发病率在8年内没有不利影响，膳食纤维摄入也没有保护作用。然而，许多研究中观察到的动物脂肪摄入量与结肠癌风险之间的正相关，为限制这种能量来源提供了充分理由。
