Feeding mice a diet rich in fish oil changes the fat composition in their breast tumors, and those tumors grow slower when treated with a common cancer drug.
Scientific Claim
Dietary supplementation with 3% fish oil concentrate increases the n-3 to n-6 fatty acid ratio in human breast cancer xenografts (MDA-MB-231) in mice by more than 10-fold, which is associated with reduced tumor growth rates during doxorubicin therapy.
Original Statement
“The ratio of n-3 to n-6 fatty acids in the tumor microsomal fraction was 1.15 ± 0.10 in FOC-fed mice versus 0.11 ± 0.10 in CO-fed mice (10.5-fold difference). The mean growth rate of tumors of FOC-fed mice was significantly less than the mean growth rate of the tumors of control mice.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The study design (non-randomized, non-blinded cohort) cannot prove causation. The verb 'associated with' correctly reflects the correlational nature of the data.
Evidence from Studies
Supporting (1)
Feeding mice fish oil made their breast tumors grow slower, especially when they also got chemotherapy, because the fish oil changed the fat makeup in the tumors and made them more vulnerable to treatment.