Nicholson A
Physicians Committee for Responsible Medicine, Washington, DC, USA.
Altern Ther Health Med. 1996 Nov;2(6):32-8.
The role of diet in breast cancer has been considered since the 1940s. However, most epidemiological studies on the incidence of the disease have been limited by their focus on one dietary component-fat-at the expense of a balanced consideration of the effect of the total diet. Further, only the intercultural comparison studies examine a wide range of fat intakes. These studies indicate a dearth of breast cancer in populations with diets in which less than 10% of calories are from fat. Although dietary fat, estrogenic food additives, and alcohol increase the risk of breast cancer, fiber, indoles, flavonols, vitamins C and E, beta carotene, and selenium are associated with a decreased risk. Except for alcohol, factors that increase risk predominate in animal products, whereas those that decrease risk abound in plant products. These factors have similar effects on progression and prognosis in breast cancer. Mechanistically, higher serum levels of estrogen have been linked with risk of breast cancer. Dietary fat, insecticide residues, and alcohol result in higher estrogen activity. A variety of plant nutrients have estrogen-blocking activity. Current evidence justifies recommending that women of all ages follow a plant-based diet in which fat provides no more than 10% of calories, with the goals of preventing breast cancer and improving its prognosis in a low-cost, safe manner.
自20世纪40年代以来，人们一直在探讨饮食在乳腺癌中的作用。然而，大多数关于该疾病发病率的流行病学研究都存在局限性，它们往往只关注一种饮食成分——脂肪，而忽视了对整体饮食效果的综合考量。此外，只有跨文化比较研究考察了广泛的脂肪摄入量。这些研究表明，在热量摄入中脂肪占比不到10%的人群中，乳腺癌发病率较低。虽然膳食脂肪、具有雌激素活性的食品添加剂和酒精会增加患乳腺癌的风险，但纤维、吲哚、黄酮醇、维生素C和E、β-胡萝卜素以及硒则与风险降低有关。除酒精外，增加风险的因素在动物产品中居多，而降低风险的因素在植物产品中大量存在。这些因素对乳腺癌的进展和预后具有相似的影响。从机制上讲，血清雌激素水平升高与乳腺癌风险相关。膳食脂肪、杀虫剂残留和酒精会导致雌激素活性增强。多种植物营养素具有雌激素阻断活性。目前的证据支持建议所有年龄段的女性采用以植物为基础的饮食，其中脂肪提供的热量不超过10%，以期以低成本、安全的方式预防乳腺癌并改善其预后。
