"Are Avocados Good for You?"
Avocados have been described as a major dietary source of antioxidants,
and this may be true compared to much
of the stuff people eat, but compared
to other common fruits, avocados are not
necessarily anything to write home about.
They do, however, contain those two carotenoid eye nutrients
found in dark green leafy vegetables, lutein and zeaxanthin,
which may explain why Mexican-Americans tend to beat out other ethnicities.
The critical carotenoids are concentrated in
the darkest green flesh close to the peel.
And because of this, consumers should be advised to use the "nick and peel" method
to obtain the nutrient-rich outer section of the avocado.
The Tufts Nutrition and Health Letter detailed what that means:
you cut in half lengthwise around the seed,
rotate a quarter-turn, and cut lengthwise again
to make quarter-avocado segments.
Then you separate the quarters and remove the seed.
And finally, starting from the tip, nick and carefully peel, so as
not to lose that nutrient-rich darkest green flesh immediately under the skin.
Avocados can also boost the absorption
of the carotenoid phytonutrients in other vegetables,
because carotenoids, like beta-carotene, are fat soluble.
However, many of our best foods for obtaining carotenoids,
like sweet potatoes, carrots, greens, contain very little fat,
so if you eat them straight, without any source of fat in your stomach,
you may end up flushing a lot of that nutrition down the toilet.
Remember, it's not what you eat, it's what you absorb.
Here's the amount of beta-carotene that ends up in your bloodstream
2, 3, 4, 5, 6 hours after eating
a little over a cup of salsa.
There's a little bump, and the same thing with the red pigment lycopene.
OK, but now here's that same amount of salsa
with an avocado added, tripling the absorption.
That means if you eat tomatoes without some source of fat at the same meal-
avocados, or nuts and seeds-
most of that bright red, beautiful lycopene will end up in the toilet bowel
rather than your bloodstream.
Same thing eating a salad, composed of lettuce, spinach, and carrots.
With a fat-free dressing, hardly any beta-carotene makes it into your body,
but add an avocado and 15 times more beta-carotene ends up
circulating throughout your body.
Do you have to use a whole avocado, though?
What about half an avocado?
Pretty much same effect; works just as well.
What about a quarter of an avocado?
We don't know the minimum amount
of dietary fat required for optimum carotenoid absorption.
It may just be a few grams per meal though,
in which case an eighth of an avocado would fit the bill,
or just one or two walnuts.
Interestingly, avocado consumption may not just enhance absorption of carotenoids,
but then also enhance their subsequent conversion inside the body into vitamin A.
People were given baby carrots with and without guacamole,
and the same thing we saw before--way more beta-carotene in the bloodstream
in the hours following the meal with the guacamole added,
compared to the same amount of carrots alone.
In fact, over 6 times more, and since beta-carotene is turned into vitamin A
in the body, there should be 6 times more vitamin A too, right?
No. They ended up with over 12 times more vitamin A.
There was also a big increase in vitamin K levels, another fat-soluble vitamin,
though that's partially because avocado contains vitamin K itself.
Not too much, though, claims this avocado industry-sponsored review,
that people on the anticoagulant medication Coumadin
have to worry, but that's not true.
We've known for decades now that even though there's not
an inordinate amount of vitamin K in avocados,
it still interferes with the drug Coumadin, also known as warfarin,
though we're not exactly sure why.
It may boost your liver's detoxifying enzymes
or prevent absorption of the drug,
but either way, those on the blood-thinner Coumadin
may want to put walnuts on their salads instead.