Why is the ratio of omega-3 & 6 in diets important?
The ratio of omega-6 to omega-3 fatty acids in the diet has far-reaching consequences for our health. During the evolution of our species the ratio is estimated to have been about 1:1, and until quite recently (as in mid-Victorian England), it remained close to that level. During the 20th century, however, the ratio changed dramatically, due to the industrialisation of soy (rich in omega-6) and reduced intakes of oily fish (critical sources of omega-3). In today’s diet, the dietary ratio of omega-6 to omega-3 is as high as 20, 30 or even 50:1. As the omega-3 fatty acids have potent anti-inflammatory effects in the body, while the omega-6 fatty acids are pro-inflammatory, this uncontrolled dietary shift has left us very vulnerable to chronic inflammation; and as chronic inflammation is a core driver for all the degenerative diseases, the change in our fatty acid intakes has had extensive and very negative health consequences.
It has also had negative effects on the brain. All cell membranes contain large amounts of fatty acids, and the ratio of the different fatty acids in the membranes, which is determined by their ratio in the diet, affects many aspects of cell function. The brain, as a membrane- and lipid-rich organ, is profoundly affected by changes in the fatty acid composition of the diet.