By Rob Schick
I ended my last post by saying we should be eating more wild-caught fish and avoiding modern seed oils, like canola, sunflower and safflower oils. The point of this is to keep a healthy balance of Omega-3 and Omega-6 fatty acids.
When I read the Hibbeln et al. article I discussed last time on this blog, I found it interesting to look at the relative balances of fatty acids in Table 1 in their paper. Unfortunately, just looking at a table of numbers doesn’t give you a good feel for the relative differences in the value of the fatty acids in the foods.
Below is a heat map of the scaled amounts of each fatty acid in the foods from the Hibbeln table. Six different fatty acids are shown here, with Omega-6s in red, and Omega-3s in blue. (For you fellow nerds, these are scaled to the maximum in each fatty acid type; in raw numbers the linoleic acid present in seed oils is extremely high.) The fatty acids, from left to right, are: linoleic acid, arachidonic acid, alpha-linoleic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoicacid.
This graphic under-represents just how much Omega-6 fats are found in each food. For example,sunflower oil has 65,700 mg/100 g. In contrast the highest fish in this table is Atlantic salmon, which has 1,115 mg/100 g. I’m not advising eating Atlantic salmon– it’s farmed and these fish typically survive on some sort of grain-based feed. Indeed, note how high Atlantic salmon is in arachidonic acid.
People often tout the benefits of grass-fed beef, and the reason for this is the increased amount of Omega-3s present. The beef shown here is likely not grass fed– hence the relative lack of Omega-3s.
Lastly, notice how high poultry is in Omega-6s. This is why many people argue infavor of grass-fed beef and lamb over poultry and pork.
My recommendation: eat the highest quality wild-caught fish and grass-fed beef that you can afford – your body and the environment will thank you.