Polyunsaturated Fats: The Double-Edged
Sword
Polyunsaturated fats are a type of dietary fat that’s
ubiquitous in our brains and bodies. The most well-known
polyunsaturated fats are the omega-3 and omega-6 fats,
which are considered essential because our bodies need
them, and we can’t produce them on our own. We therefore
have to get these fats from food.
Two of the most important omega-3 fats are
eicosapentaenoic acid (EPA) and docosahexaenoic acid
(DHA). These are the “good” fats found in fish such as wild
salmon, mackerel, and sardines, in krill, and in certain algae.
They’re also found in smaller amounts in grass-fed beef and
pasture-raised eggs. While EPA is a whole-body anti-
inflammatory agent, DHA is the most important and
abundant structural component of healthy brain cells.
Another form of omega-3 found in plants is called alpha-
linolenic acid (ALA). ALA needs to be converted to EPA
and DHA to be utilized by your cells, but the body’s ability
to do this is highly limited and varies in efficacy from
person to person (I’ll come back to this).
On the other side of the polyunsaturated coin, we have
the omega-6 fatty acids. These are also essential to a healthy
brain, but the American diet now includes far too many of
them in the form of linoleic acid. These omega-6 fats went
from appearing in our diet as oils delivered in trace
quantities by whole foods to becoming major caloric
contributors to the American diet in just a few short decades.
They are the predominant type of fatty acid found in the