chlorophyll, including what foods it can be found in

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chlorophyll, including what foods it can be found in

 

Although it's not very well known in the world of nutrition,

chlorophyll couldn't be more important in the world of biology and

plants. All green plants contain at least one type of chlorophyll

(chlorophyll a). Plants that evolved at a later point in history

( " higher plants " ) also contain a second type of chlorophyll

(chlorophyll b). There are also forms of chlorophyll called

chlorophyll c1, c2, and c3, as well as a chlorophyll d, but these

forms are much less widely distributed in the plant world. Chlorophyll

is the single most critical substance in plants that allows them to

absorb light from the sun and convert that light into usable energy.

(In biochemistry, it's called the primary photoreceptor pigment).

 

In many vegetables, there is slightly more chlorophyll a than

chlorophyll b, and this slight edge in favor of chlorophyll a tends to

decrease as the plant ages. However, research studies have yet to

clarify what the exact health significance is of this chlorophyll a-to-

chlorophyll b ratio.

 

The color of chlorophyll

 

It's usually easy to tell when a food has significant amounts of

chlorophyll, because chlorophyll provides the green color that is

found in grasses, leaves, and many of the vegetables that we eat.

These plants and foods would not be green without their chlorophyll,

since chlorophyll pigments reflect sunlight at exact appropriate

wavelengths for our eyes to detect them as green. The chlorophyll a

molecule actually reflects light in a blue-green range (about 685

nanometer wavelengths), while chlorophyll b reflects light in a more

yellow-green color (about 735 nanometer wavelengths). The overall

affect, however, is for us to see varying shades of a color we would

simply call " green. "

 

Foods that contain chlorophyll

 

While all green plants contains chlorophyll a, and most vegetables

that we eat contain both chlorophyll a and chlorophyll b, some

vegetables contain particularly high amounts of total chlorophyll.

Best studied of all the vegetables is spinach (Spinacia oleracea in

the Latin scientific name), with this vegetable containing about

300-600 milligrams per ounce.

 

To understand how high in chlorophyll this amount turns out to be,

compare the chlorophyll content of spinach to another of the World's

Healthiest Foods - olives. Chlorophyll is one of the primary pigments

in olives, but olives contain only 30-300 micrograms per ounce (about

1/1000th as much as spinach). Some olive oil producers deliberately

allow leaves to be placed in the olive presses to increase the

chlorophyll and " grassiness " of the olive oil.

 

All of the green vegetables in the World's Healthiest Foods -

asparagus, bell peppers, broccoli, Brussels sprouts, green cabbage,

celery, collard greens, green beans, green peas, kale, leeks, green

olives, parsley, romaine lettuce, sea vegetables, spinach, Swiss

chard, and turnip greens are concentrated sources of chlorophyll.

 

Chlorophyll and health

 

Research on the health benefits of chlorophyll has focused on the area

of cancer (including treatment and prevention). This research got

underway when damage to genes (or more precisely, to the genes' DNA)

by carcinogenic substances called aflatoxins (or more precisely

aflatoxin B1, or AFB1), was found to be prevented by chlorophyllin.

Chlorophyllin is a derivative of chlorophyll in which the magnesium in

its center is removed (usually by placing it in an acid bath in a

science lab) and replaced with copper.

 

Research studies in humans have found that damage to DNA by aflatoxin

can be decreased as much as 55% through supplementation with

chlorophyllin at 100 milligrams, three times a day, for four months.

This amount of chlorophyllin, 300 milligrams per day, is the same

amount of chlorophyll found in one weighted ounce of spinach (a little

over 1/2 cup of chopped raw spinach). Although research is still in

the early stage, prevention and treatment of liver cancer, skin

cancer, and colon cancer are all being investigated in relationship to

intake of chlorophyll-containing vegetables and supplementation with

chlorophyllin.

 

The effect of cooking on chlorophyll

 

One of the primary reasons for the change in color when green

vegetables are cooked is the change in chlorophyll. What happens

during this process is actually quite interesting.

 

The chemical perspective

 

Chlorophyll has a chemical structure that is quite similar to a

chemical structure found within our red blood cells. A basic

difference is the fact that this structure (called a porphyrin ring)

contains an atom of iron at its center when it is found in our red

blood cells, but when it is found in plants, it contains an atom of

magnesium at the center. When plants are heated and/or exposed to acid

(and when green vegetables are cooked and/or exposed to acid), the

magnesium gets removed from the center of this ring structure and

replaced by an atom of hydrogen. (In biochemistry, the chlorophyll a

gets turned into a molecule called pheophytin a, and the chlorophyll b

gets turned into pheophytin b). With this one simple change, the color

of the vegetable changes from bright green to olive-gray. (The

pheophytin provides a green-gray color, and the pheophytin b provides

an olive-green color).

 

The practical perspective

 

The jury is definitely still out on the impact of cooking on

chlorophyll. At one end of the spectrum, it's totally clear that

dramatic loss of chlorophyll occurs after prolonged cooking. In

studies on broccoli, for example, about two thirds of the chlorophyll

was removed after 20 minutes of boiling. Researchers have also

determined that there are steadily increasing losses of both

chlorophyll a and chlorophyll b when the boiling time for broccoli is

increased from 5 to 20 minutes. However, at cooking times less than

five minutes, the research is not as clear, and some studies suggest

that brief steaming of vegetables like spinach actually increases the

amount of chlorophyll that can be absorbed into our body.

 

Whenever a vegetable is cooked long enough to cause a change in color

from bright green to olive-gray, we know that some of the chlorophyll

a and chlorophyll b in the vegetable have been changed to pheophytins

a and b. This color change is one of the reasons we have established

the relatively short steaming times for green vegetables in the

World's Healthiest Cooking techniques! Our cooking methods are

designed to preserve the unique concentrations of chlorophyll found in

these magnificent vegetables.

 

Practical tips

 

Overcooking is particularly important to avoid when it comes to

chlorophyll, but with very short steaming times, the chlorophyll

content of these foods is preserved, and absorption of chlorophyll

from these foods may actually be increased. Consumption of these green

vegetables in raw form is also an excellent way to obtain the health

benefits of chlorophyll.

 

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