Lake trout (Salvelinus namaycush), also known as lake char, is a fatty fish found primarily in U.S. and Canadian lakes such as the Great Lakes. Lake trout is a good source of choline, niacin, selenium, vitamin B6, vitamin D and omega-3 fatty acids, all of which have been associated with lower risk of certain cancers, including breast cancer. Consumption of fatty fish or fish oil has been found to reduce the risk of coronary heart disease. Eating fatty fish such as lake trout has been found to be associated with reduced risks of leukemia, multiple myeloma, and non-Hodgkin lymphoma, as well as renal cell, endometrial and prostate cancer.
Generally speaking, the benefits of consuming fatty fish, including lake trout, are thought to outweigh the potentially detrimental effects of the toxins from pollution and other sources that tend to accumulate in their adipose tissue. Lake trout is not considered a high mercury fish, although relatively high levels have been recorded in lake trout from some Canadian lakes. Depending on its location, lake trout can accumulate levels of polychlorinated biphenyls (PCBs) and other contaminants high enough to be detrimental to human health. Exposure to PCBs has been associated with increased risk of developing breast, prostate, testicular, ovarian and endometrial cancers.
Breast cancer-related effects of eating lake trout
Like other fatty fish, lake trout is a significant source of the marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These fatty acids have been shown to inhibit proliferation of breast cancer cells in the laboratory. Fish protein hydrolysates also have been shown to have antiproliferative activity against human breast cancer cell lines.
Most, but not all, epidemiological studies have found convincing evidence of a negative association between DHA and EPA intake or fatty fish consumption and the risk of breast cancer. In addition, several studies have found that higher dietary omega-3 to omega-6 fatty acid intakes are associated with reduced risk of breast cancer; consuming lake trout would tend to improve this ratio for most women.
Marine fatty acids have also been found to enhance the therapeutic effects of tamoxifen and chemotherapy drugs such as Adriamycin and Taxol. However, note that recent research suggests that lake trout and similar fish should not be consumed the day before through the day after a chemotherapy treatment and consumed only in moderation during the remaining days of each cycle. Fish similar to lake trout have been shown to incorporate a fatty acid (hexadeca-4,7,10,13-tetraenoic acid) that can induce resistance to a broad spectrum of chemotherapy drugs.
Lake trout should not be confused with rainbow trout (Oncorhynchus Mykiss), which is one of the most common farmed fish and does not have the same favorable omega-3 fatty acid profile.
Pan frying fatty fish has been shown to release carcinogenic heterocyclic amines (HCAs) in concentrations high enough to affect human health. Population studies have also found that consumption of fried fish is associated with increased risk of breast cancer.
While the situation has improved in recent years, the Great Lakes are contaminated with many pollutants, including PCBs, polychlorinated dibenzo dioxins and furans, polybrominated diphenyl ethers, and mercury, as well as chlorinated pesticides such as dichlorodiphenyltrichloroethane (DDT) and its metabolites. As a large predatory fish at the top of its food chain, lake trout tends to accumulate PCBs and other environmental contaminants. The U.S. Environmental Protection Agency and Environment Canada perform ongoing monitoring of whole-body contaminant levels of top predator fish such as lake trout. Generally speaking, women can safely eat up to eight servings of lake trout per month. However, lake trout should be avoided by pregnant women and nursing mothers due to its contaminant content. Removing the skin from lake trout is recommended to reduce the level of contaminants ingested.
Below are links to recent studies concerning this food. For a more complete list of studies, please click on lake trout.