From the beginning of human evolution up until about 1920, the human diet consisted of
between a 1:1 and a 2:1 ratio of omega-6 to omega-3 essential fatty acids.^1 The modern
(American) diet has shifted this balance to between 10:1 and 30:1, as omega-3 essential
fatty acids have declined due to (1) the prevalent use of omega-6 seed oils (especially corn)
instead of omega- 3 - rich plants to feed the animals and farmed fish that make up our animal
protein, (2) decline of fish consumption and general lack of flax seed oil, canola oil, walnuts,
and leafy green vegetables in our diet, (3) hydrogenization of oils for use in processed
foods, thus increasing trans-fatty acid intake which interferes with fatty acid synthesis (4)
loss of cereal germ by modern milling processes, and (5) increase in sugar intake which
interferes with the enzymes of fatty acid synthesis.^2
Hibbeln has shown that depression is inversely correlated with fish consumption. Japan has
the lowest levels of depression (0.12% of population), Iceland the lowest levels of bipolar
depression, and Hong Kong the lowest homicide levels. These countries also have the fish
oil consumption with about 730 to 1000 mg per day of EPA and DHA, compared to the US,
where consumption of EPA and DHE on average is about 180 mg per day.^3
Stoll presents studies of the blood and tissue characteristics of people with major
depression.^4 These studies are striking, showing the correlation of EPA depletion with
clinical symptoms of depression, using the usual clinical scales.
EFFICACY: Although larger and longer-term studies of depression are needed, as are studies
targeting the effect of omega-3 essential fatty acid supplementation on other mental health
conditions, and the sources consulted for this outline are split, it appears likely that omega-
3s will eventually be found effective as CAM treatments for bipolar disorder and
depression and to enhance the effectiveness of conventional anti-depressants. Of eight
sources that discuss omega-3s, three sources do not recommend omega-3 supplementation
