This article is the first part of our four-article series about chlorophyll, including its role in health, its concentration in different foods, and its . This undervalued nutrient can make an important contribution to your health and is worth preserving in the way that you cook and prepare your foods. This first article will give you a basic understanding of chlorophyll itself.
Although it's not very well known in the world of nutrition, chlorophyll has earned its stripes as a nutrient widely present in food—especially green vegetables—and that provides us with well-documented health benefits. In science, the importance of chlorophyll is sometimes woven into the very definition of a "plant," since plants can be described as organisms that get their energy from the sun and rely on chlorophyll to accomplish this task. Just as our bodies rely on mitochondria) in our cells for energy production, so plants rely on chloroplasts, which are the energy producing structures in their cells. Chlorophyll is the molecule that is stored inside the plant chloroplasts and it allows plants to take sunlight and convert it into usable energy. In other words, chlorophyll is one of the keys to plant life!
Chlorophyll is most perhaps most famous for its green color. That's because chlorophyll pigments absorb red and blue wavelengths of light but reflect green wavelengths. When a green bell pepper starts to turn red, what you are seeing is a gradual decrease in the relative amount of chlorophyll in the green bell pepper (which gets broken down during ripening) and a gradual increase in the relative amount of carotenoids (especially capsanthin, capsorubin, and beta-cryptoxanthin). Early young olives (depending on the variety) look greener because their chlorophyll content exceeds their carotenoid content. When they turn purple-black at full ripening, this color change is due to increased synthesis of dark purple anthocyanin pigments that overtake the greenness of their chlorophyll. Although plants can have many different pigments (64 different pigments have been analyzed in bell peppers), you can be certain that a vibrant green vegetable contains a substantial amount of chlorophyll!
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. Recent studies on the health benefits of chlorophyll suggest that some metabolites (metabolically altered versions) of chlorophyll have health benefits as well. These "relatives" of chlorophyll include 7-hydroxylmethl chlorophyll, 132-hydroxy-chlorophyll, and 151-hydroxy-lactone-chlorophyll. In general, most studies on the health benefits of chlorophyll have focused on total chlorophyll intake rather than specific forms of this nutrient.
At the center of the chlorophyll molecule is an atom of magnesium. Magnesium contained inside of chlorophyll shows better absorption and bioavailability in some studies. However, since only 2-3% of the total magnesium found in common vegetables appears to be bound together with chlorophyll, this form of magnesium appears to contribute a relatively small amount to our overall intake of magnesium. For example, spinach contains more magnesium than of our 100 WHFoods (156 milligrams per cooked cup). With only 2-3% of chlorophyll-bound magnesium, however, the chlorophyll found in spinach would only be providing us with 3-5 milligrams of this mineral.
Like carotenoids, chlorophyll is a fat-soluble nutrient and gets carried around the body in a specialized fat-containing molecular group called a micelle. Research on carotenoids has shown that these yellow/orange pigments are best absorbed in a fat-containing meal. (Only a few grams of fat seem to be required to improve carotenoid absorption, and some carotenoid-containing foods naturally contain this small amount of fat.) We have yet to see research showing that minimal amounts of dietary fat are helpful in absorption of chlorophyll, but this possibility seems logical given chlorophyll's fat-soluble nature. Our , for example, might provide you with about 100 milligrams of chlorophyll since spinach is a high-chlorophyll vegetable with about 24 milligrams per cup (raw). There would also be plenty of fat in this recipe to assist with absorption of chlorophyll, if this pigment does in fact turn out to have better absorption along with fat intake, similar to the carotenoid pigments (like beta-carotene).