Eating fish has no association with breast cancer risk. The results of these studies are in general agreement. Ten of thirteen studies saw no connection between eating fish and breast cancer risk. Of the studies that did see a connection between eating fish and breast cancer risk, two reported an increase in risk and one reported a decrease in risk. The studies described above examined fish in general rather than fish oil.
Fish living in contaminated waters can accumulate environmental contaminants.
Studies of breast cancer in women who eat sport fish caught in contaminated waters have not been conducted. These concerns would not include fish bought in grocery stores, which are tested by the United States Food and Drug Administration. Eating cured meats may be associated with an increased risk of breast cancer. This conclusion is not definite because of the same study problems discussed above. In addition, all of the studies of this topic did not define cured meats the same way and were not always looking at the same products.