The avocado native to Mexico and
Central America, classified in the flowering plant family Lauraceae along with
cinnamon, camphor and bay laurel
Many of healthy foods provide with
carotenoids. These orange-yellow pigments offer outstanding health benefits—but
only if they are absorbed up into the cells. Intake of fat along with
carotenoids greatly helps to improve their absorption. However, many of our
best foods for obtaining carotenoids—for example, sweet potatoes, carrots, and
leafy greens—contain very little fat (less than 1 gram per serving). As a
special step for improving carotenoid absorption from carotenoid-rich foods,
researchers have experimented with the addition of avocado to meal choices
including salads, side servings of leafy greens, side servings of carrots, or
tomato sauce. The amount of avocado added has varied from study to study but
averages approximately 1 cup or 1 small/medium avocado providing 20-25 grams of
total fat. As expected, this added avocado has been shown to increase
carotenoid absorption from all of the foods listed above. Anywhere from two to
six times as much absorption was found to occur with the added avocado! But in
addition to this increased absorption was a much less anticipated result in a
recent study: not only did avocado improve carotenoid absorption, but it also
improved conversion of specific carotenoids (most importantly, beta-carotene)
into active vitamin A.
Avocados do contain carotenoids, in and of
themselves. And thanks to their fat content, we can get good absorption of the
carotenoids that they contain. However, if we happen to be consuming an
avocado-free meal or snack that contains very little fat yet rich amounts of
carotenoids, some added avocado might go a long way in improving your
carotenoid absorption and vitamin A nourishment. Salad greens—including romaine
lettuce—and mixed greens like kale, chard, and spinach are great examples of
very low fat, carotenoid-rich foods that might be eaten alone but would have
more of their carotenoid-richness transferred over into our body with the help
of some added avocado.
The method we use to peel an avocado might
make a difference to our health. Research on avocado shows that the greatest
phytonutrient concentrations occur in portions of the food that we do not
typically eat, namely, the peel and the seed (or "pit.") The pulp of
the avocado is actually much lower in phytonutrients than these other portions
of the food. However, while lower in their overall phytonutrient richness, all
portions of the pulp are not identical in their phytonutrient concentrations
and the areas of the pulp that are closest to the peel are higher in certain
phytonutrients than more interior portions of the pulp. For this reason, we don't
want to slice into that outermost, dark green portion of the pulp any more than
necessary when we are peeling an avocado. Accordingly, the best method is what
the California Avocado Commission has called the "nick and peel"
method. In this method, we actually end up peeling the avocado with your hands
in the same way that we would peel a banana. The first step in the
nick-and-peel method is to cut into the avocado lengthwise, producing two long
avocado halves that are still connected in the middle by the seed. Next we take
hold of both halves and twist them in opposite directions until they naturally
separate. At this point, remove the seed and cut each of the halves lengthwise
to produce long quartered sections of the avocado. we can use our thumb and
index finger to grip the edge of the skin on each quarter and peel it off, just
as we would do with a banana skin. The final result is a peeled avocado that
contains most of that dark green outermost flesh, which provides you with the
best possible phytonutrient richness from the pulp portion of the avocado.
Recent research on avocado and heart
disease risk has revealed some important health benefits that may be unique to
this food. Avocado's reputation as a high-fat food is entirely accurate. Our
1-cup website serving provides 22 grams of fat, and those 22 grams account for
82% of avocado's total calories. And they do not necessarily provide a
favorable ratio of omega-3 to omega-6 fat; we get less than 1/4 gram of
omega-3s from one serving of avocado and 2.5 grams of omega-6s, for a ratio of
10:1 in favor of omega-6s. However, despite these characteristics, the addition
of avocado to already well-balanced diets has been shown to lower risk of heart
disease, improve blood levels of LDL, and lower levels of oxidative stress in
the bloodstream following consumption of food. In one particular research
study, participants in two groups all consumed a diet with the same overall balance,
including 34% fat in both groups. But one avocado per day was included in the
meal plan of only one group, and that was the group with the best heart-related
results in terms of blood fat levels.
Most researchers are agreed that the high
levels of monounsaturated fat in avocado—especially oleic acid—play a role in
these heart-related benefits. Nearly 15 out of the 22 grams of fat (68%) found
in one cup of avocado come from monounsaturated fat. (And by contrast, less
than 3 grams come from the category of polyunsaturated fat, which includes both
omega-6s and omega-3s.) This high level of monounsaturates puts avocado in a
similar category with olives, which provide about 14 grams of fat per cup and
approximately 73% of those grams as monounsaturates. In addition to its high
percentage of monounsaturated fat, however, avocado offers some other unique
fat qualities. It provides us with phytosterols including beta-sitosterol,
campesterol, and stigmasterol. This special group of fats has been shown to provide
important anti-inflammatory benefits to our body systems, including our
cardiovascular system. Not as clear from a dietary standpoint are the
polyhydroxylated fatty alcohols, or PFAs, found in avocado. PFAs are a group of
fat-related compounds more commonly found in sea plants than in land plants,
making the avocado tree unusual in this regard. However, the studies that we
have seen on PFAs and avocado have extracted these PFAs from the seed (or pit)
of the fruit, rather than the pulp. Since we typically do not consume this part
of the avocado, the practical role of these PFAs from a dietary standpoint is
less clear than the role of monounsaturates and phytosterols described above.
No comments:
Post a Comment