Posted by Larry Hoover on April 19, 2003, at 12:15:19
In reply to Larry/Ritch/Noa, posted by McPac on April 11, 2003, at 23:30:50
> My question is at the END of this study.
>
> Fish oil and margarine don't go together
> ADELAIDE, AUSTRALIA. Fish oil supplements containing EPA (eicosapentaenoic acid) have an anti-inflammatory effect and may benefit people suffering from rheumatoid arthritis and psoriasis. This beneficial effect is significantly reduced when the diet is high in linoleic acid. A seven week controlled experiment involving 30 male volunteers was recently completed in Australia. The participants were given 1.6 gram EPA and 0.32 gram DHA (docosahexaenoic acid) daily. Half the volunteers were kept on a diet high in linoleic acid by using margarine as a spread and polyunsaturated oils for cooking. The other half used butter and olive oil which are low in linoleic acid. The experiment clearly showed that the incorporation of fish oil is enhanced by a diet containing butter and fish oil. Margarine and polyunsaturated oils had an inhibiting effect and should therefore be excluded from the diet in order to obtain maximum benefit from fish oil.
> Cleland, Leslie G., et al. Linoleate inhibits EPA incorporation from dietary fish-oil supplements in human subjects. American Journal of Clinical Nutrition, Vol. 55, February 1992, pp. 395-99
>
> So, is the margarine and linoleic acid negating the fish oil benefits only for people taking it for psoriasis & rheumatoid arthritis (inflammatory problems) OR is the linoleic acid reducing the fish oil benefits for EVERYBODY taking fish oil for ALL conditions, such as depression?It would appear that linoleate intake is a strong determinant of EPA uptake and incorporation into phospholipids, but does not affect DHA. This is true for all people, I would think. It's quite obvious in the following study in rats, too.
Biochim Biophys Acta 1992 Dec 2;1165(2):194-200
Influence of an increased intake of linoleic acid on the incorporation of dietary (n-3) fatty acids in phospholipids and on prostanoid synthesis in rat tissues.
Raederstorff D, Moser U.
F. Hoffman-La Roche, Department of Vitamin and Nutrition Research, Basel, Switzerland.
We investigated whether the amount of dietary linoleic acid (LA) (as corn oil) influences the incorporation of dietary eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in tissue phospholipids and the prostanoid biosynthesis. Rats were fed four different levels of corn oil (at a total dietary fat level of either 2.5%, 5%, 10% or 20%); at each corn oil level, two groups of rats were supplemented with either EPA and DHA (200 mg/day) during 6 weeks, and compared with a group receiving oleic acid. The phospholipid fatty acid composition of liver, kidney and aorta showed, as expected, that the incorporation of EPA was highly suppressed by increasing the content of dietary linoleic acid in the diets. On the other hand, DHA was almost unaffected by the amounts of (n - 6) fatty acids in the diets. These results indicate that EPA levels but not DHA levels in tissue phospholipids were influenced by the competing dietary (n - 6) fatty acids. The tissue arachidonate content was similar under the various dietary linoleic acid conditions, but feeding EPA or DHA lowers the AA content. Moreover, the amount of dietary linoleic acid did not significantly influence the prostaglandin E2 (PGE2) production in stimulated aortic rings. However, PGE2 synthesis was significantly decreased in the groups treated with either EPA or DHA. Thromboxane B2 levels in serum followed a similar pattern. It is suggested that an increase of dietary (n - 3) PUFAs is more efficient to reduce (n - 6) eicosanoid formation than a decrease of dietary (n - 6) fatty acids.
poster:Larry Hoover
thread:216908
URL: http://www.dr-bob.org/babble/20030417/msgs/220621.html