What about the Omega-3 and Omega-6 imbalance?
The overall effect of this is to change the "balance" of the two types of polyunsaturates in diet. Experts think that man evolved on a diet which would have had roughly 1-2 times more Omega-6 than Omega-3, though there is a school of thought which argues for a 1:1 ratio. Currently, average UK intakes are in a ratio of around 8:1 in favour of the Omega-6, while in the US it is around 10:1, and in Australia nearer 12:1. Many individuals within those populations will have more extreme intakes.
The diet typical of the industrialised, principally Western, nations now provides an over-abundance of the Omega-6s - mainly from sunflower oil margarines and vegetable cooking oils. At the same time intake of the Omega-3 has dropped by more than half. This is because animals are now reared differently and the typical Western diet is high in cereals and low in fish. Of the fish that is eaten, by far the majority is of a type with low fat levels (cod and haddock) compared with the fish popularly eaten 100 years ago (herring and mackerel).
