Chlorophyll is the pigment that gives plants their green color. It is responsible for initiating photosynthesis by absorbing light and transferring the energy from that light to other molecules.
What's photosynthesis got to do with it?
You may think that photosynthesis has nothing to do with nutrition, but actually it is basic to healthy eating and your survival. Photosynthesis is the process by which plants use light energy plus carbon dioxide and water to make carbohydrates. In this process, the energy from the light is stored in the carbs, so that when you eat them, your body can release the stored energy you need to live.
Another way to say this is that chlorophyll is the agent that allows you to access the energy from the sun for use in our own bodies.
Meat-eaters need that green pigment, too!
Even if you don't eat many plants, and focus instead on meat, you are still dependent on photosynthesis, since the meat you eat was produced by feeding plants to animals. The animal uses the energy in the plant to grow and also stores some of the energy in its muscles. Then when you eat the meat, your body can access the energy, in the form of carbohydrates and protein, through metabolic processes.
It supplies magnesium, too.
As you can see from the graphic, magnesium (Mg) forms part of the chlorophyll molecule, so when you eat green plants, especially dark leafy ones, you are eating the green pigment, and thus, magnesium!
You may have come across potatoes that have an unnatural green cast to their skins. This hue is caused by a green coating that is under the thin skin of the potato, and is nothing more than chlorophyll.
Potatoes that are stored improperly or for too long will suffer from excessive exposure to light and heat, which produces this effect. So rather than being unripe as you might think, green potatoes are actually, in a sense, over-ripe!
Green potatoes signal buildup of solanine
In the case of green potatoes, the chlorophyll, in itself, is not a problem, but its presence under the skin of a potato is associated with the production of a toxin called solanine. Ingesting too much of this toxin can cause symptoms of food poisoning including nausea, diarrhea, vomiting, abdominal pain, confusion, shortness of breath, convulsions and even death.
Here are some tips to help you avoid green potatoes:
-Check for greening before you buy
-Store potatoes in a cool, dark place
-Use potatoes you buy within a few weeks
How much does it take?
There is some controversy about how much solanine it would take to make you ill, but if you find your potatoes have a green skin or a green layer under the skin, you may want to discard them to be completely safe.
On the other hand, there are some health eating experts that consider it safe to remove all green parts and sprouts from the potatoes before cooking. One caveat to this approach is that, if the potato tastes bitter after cooking, the potatoes should be discarded, since that may indicate the presence of the toxin.
As with any toxin, the danger is higher for children, the elderly, pregnant women and those with a compromised health status, and extra care should be taken with food fed to these groups.