Defending Olive Oil’s Reputation
Mark’s Daily Apple
by Mark Sisson: 7
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reputation has been besmirched. It isn't the magic life elixir fueling
the teeming hordes of Mediterranean-dieting,
crusty bread-eating, moderate wine-drinking centenarians, but it
doesn't deserve to be tossed in the trash heap with soybean, grapeseed,
corn, and canola oils. I sense that it's fast becoming a "fallen
fat" among our crowd and I think it's a darn shame. Are a few extra
grams of linoleic acid, one or two unfortunate incidents
of adulterated oil, and gushing praise from vegans, vegetarians,
and the American Heart Association alike enough to turn us against
a staple, phenolic-rich food sporting several thousand years of
Allow me to
explain myself. Early this week, I got an email from a reader: "I
often roast my veggies with EVOO. Would butter be a better alternative,
or are the fats in EVOO just as well?" This is an extremely common,
totally innocent question. I get similar questions a few times each
week. Moreover, I've noticed a general undercurrent across the paleosphere
of folks avoiding olive
oil altogether, either because it isn't necessary for health,
has too much linoleic acid, or it's too prone to oxidative damage
when exposed to the elements (heat, oxygen, light). I'd like to
address each of these, particularly the oxidative stability. And
I'll answer whether I think we can cook with it or not.
Do we need
Now, you don't
need to eat olive oil to be healthy – agreed. I would enjoy life
less without good extra virgin olive oil, but I could be healthy
without it and I can see why people would find it unnecessary. Besides,
good olive oil can be hard to find or expensive, while a slab of
butter is almost always more affordable.
Is there too
Olive oil does
have a fair amount of linoleic
acid, with some varieties reaching concentrations of 20%. Using
such a variety for the majority of your added cooking and salad
fat – especially on a high-fat
Primal Blueprint eating strategy – would mean eating excessive
amounts of omega-6. Note, though, that some olive oil varieties
are far lower in linoleic acid, and most extra virgin olive oil
runs about 10%. Two tablespoons of the average stuff gives you about
2.8 grams of linoleic acid. That's less omega-6
than most lard
and poultry fat, if you're counting, especially if you use it
sparingly as a drizzler or in salads.
oil too unstable for regular eating? What about the oxidation?!?
As for the
oxidative potential of olive oil, that depends on a few things.
Your olive oil is only as unstable as its environment. Heat, light,
and exposure to oxygen all impact the oxidative stability of olive
oil, as does the presence of antioxidants and phenolics. Of course,
this is all works in a dose dependent manner; the more heat, light,
and oxygen exposure, the greater the oxidative potential, while
the more antioxidants
and phenolics present, the lower the oxidative potential. Ultimately,
it's up to you to source good quality oil and store and handle it
properly. If you buy your olive oil at Costco in two-gallon clear
plastic jugs, don't be surprised when it doesn't hold up as well
as the extra virgin deep green olive oil that leaves streaks of
olive sediment behind and burns your throat going down. If you store
your olive oil next to the stove, often forget to secure the cap,
and expose it to plenty of kitchen lighting, it's not going to last
heating it? Should you ever cook with olive oil?
such a fragile plant oil will render it inedible, toxic, and liable
to result in oxidized serum lipids if eaten. Right? Not so fast.
While subjecting extra virgin olive oil to high heat can alter the
taste, it's actually fairly resistant to oxidative damage from cooking.
Let's take a look at some studies to make sure:
one study, the authors heated various oils to "deep-frying conditions"
and checked oxidative markers every three hours. The olive oils
made it 24-27 hours of constant high heating before reaching the
maximum legal value of heat damage. Not bad, and it's not like you're
going to use your olive oil to deep fry anyway.
heated at 180 degrees C (356 degrees F) for 36 hours, two varieties
of extra virgin olive oil exhibited
strong resistance to oxidative damage and retained most of their
"minor [phenolic] compounds."
But then there's
study, in which subjects were given heated olive oil meals,
heated safflower oil meals, unheated olive oil meals, and unheated
safflower oil meals. Both of the heated oils and the unheated safflower
oil resulted in elevated postprandial oxidative markers, while eating
unheated olive oil resulted in none. Note, though, that the olive
oil was probably refined or light (otherwise they would have called
it "virgin" or "extra virgin") and thus devoid of significant phenolics
with antioxidant properties. Also, the oils were heated at 210 degrees
C (410 degrees F) for eight hours, which seems excessive. The home
cook sauteeing some shrimp and onions in white wine and EVOO is
unlikely to hit 210 degrees C, let alone stay there for eight hours.
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March 24, 2011
© 2011 Mark's Daily Apple
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