the primary fat in extra-virgin olive oil). While the details
are still being unraveled, you can rest assured that what’s
good for your body is also very likely good for your brain.
What we’re beginning to learn is that nutritionally poor
Westernized diets that are rich in processed polyunsaturated
oils and rapidly digestible carbohydrates are the true culprits
in not only cardiovascular disease but obesity and type 2
diabetes—and, as research is now making clear, brain
disease as well.
For these reasons, I place no restriction on the
consumption of saturated fats when they are contained in
whole foods, or when they are used for occasional higher-
heat cooking. (The main oil in your diet should always be
Genius Food #1—extra-virgin olive oil.)
Trans Fats: A Fat to Be Feared
Trans fats are unsaturated fats that behave in some ways like
saturated fats. One naturally produced trans fat, conjugated
linolenic acid (CLA), is found in the milk and meat products
of grass-fed animals, and is believed to be very healthy,
associated with better metabolic and vascular health and
reduced cancer risk. But natural trans fats are relatively rare
in the modern human diet.
The bulk of trans fats consumed by humans are the
result of industrial manufacturing. These man-made trans
fats are not just bad; they’re Darth Vader–meets–Lord
Voldemort bad. They begin life as polyunsaturated oils
(which can freely pass the blood-brain barrier), and are