Boyd N F, Cousins M, Lockwood G, Tritchler D
Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto, Canada.
Lipids. 1992 Oct;27(10):821-6. doi: 10.1007/BF02535857.
Animal experimental evidence and human ecological data suggest that dietary fat intake is related to breast cancer risk. Epidemiological studies within countries have given inconsistent results but are limited by the restricted range of dietary intake found in Western populations and by error in the measurement of fat consumption. Experimental evidence, derived from controlled clinical trials in which the range of fat intake is increased beyond that seen in most Western populations, is capable of overcoming this limitation of observational epidemiology, and would provide the strongest evidence available concerning the relationship of dietary fat intake to breast cancer risk. Further, such trials are the only means likely to answer the question of whether breast cancer risk in high-risk subjects can be modified by changing dietary fat intake. We describe here several aspects of the feasibility of an experimental approach to this problem, including the identification of subjects at increased risk for breast cancer, and the demonstration that such subjects will enter a clinical trial of dietary fat reduction and comply with a low-fat diet. It is shown that subjects can be recruited and retained in such trials, that satisfactory dietary compliance can be achieved over at least 24 mon and that the subjects selected are at demonstrably increased risk of breast cancer. This finding indicates that it is feasible to test the dietary fat-breast cancer hypothesis experimentally by means of a clinical trial.
动物实验证据和人类生态学数据表明，膳食脂肪摄入量与乳腺癌风险相关。各国开展的流行病学研究结果并不一致，且受西方人群膳食摄入量范围有限以及脂肪摄入量测量误差的限制。来自对照临床试验的实验证据，其中脂肪摄入量范围增加到超过大多数西方人群的水平，能够克服观察性流行病学的这一局限性，并将提供关于膳食脂肪摄入量与乳腺癌风险关系的最有力证据。此外，此类试验是唯一有可能回答高风险受试者的乳腺癌风险是否可通过改变膳食脂肪摄入量来改变这一问题的方法。我们在此描述针对该问题采用实验方法的可行性的几个方面，包括识别乳腺癌风险增加的受试者，以及证明此类受试者将参加膳食脂肪减少的临床试验并遵守低脂饮食。结果表明，可以招募并留住此类试验的受试者，至少在24个月内可以实现令人满意的饮食依从性，并且所选受试者患乳腺癌的风险明显增加。这一发现表明，通过临床试验以实验方式检验膳食脂肪与乳腺癌假说具有可行性。
