Health benefits from low n-6:n-3 fatty acid (FA) ratio on cardiovascular
risk have been shown. However, the impact of the source of n-3 FAs has
not been fully investigated. Our purpose was to investigate
cardiovascular benefits of oils with a low ratio of n-6:n-3 FAs, but
different sources of n-3 FAs. Mice were divided into 3 groups (n=7) and
fed a diet supplemented with either a fish or flaxseed oil-based
`designer oils` with an approximate n-6:n-3 FA ratio of 2/1 or with a
safflower-oil-based diet with a ratio of 25/1, for 16 weeks. Plasma
lipids and fatty acid profile of the liver and heart tissues were
characterized. Plasma cholesterol levels were reduced in both fish and
flax groups by 27% and 36%, respectively, as compared to controls at
endpoint. The levels of EPA and DHA in liver phospholipids were
significantly increased in both fish and flax groups as compared to the
control group, with more profound increases in the fish group.
Arachidonic acid levels were similarly decreased in the liver tissues
from both fish and flax groups as compared to controls. Our data
indicates that health benefits may be achieved by lowering dietary
n-6:n-3 FA even in a high fat diet medium.