In one word, "yes." Even though we would describe the health research on dietary chlorophyll to be in its early stages, studies have repeatedly shown health benefits from consumption of this phytonutrient.
Chlorophyll has been shown to have antioxidant properties, even though its role in our overall antioxidant protection may be smaller than the role of carotenoids like beta-carotene or vitamins like vitamin E or vitamin C. In one study that we reviewed, intake of green lettuce was found to increase the antioxidant capacity of our bloodstream, and researchers were able to link this increased antioxidant capacity to the chlorophyll contained in the green lettuce.
There has been some uncertainty in this area of research on chlorophyll and its antioxidant benefits, however, and this uncertainty has been related to the way in which chlorophyll provides its antioxidant protection. (In technical terms, chlorophyll may not function as a hydrogen donor in the same way as other common antioxidant nutrients but may help prevent oxidative damage in other ways.) Nevertheless, studies on the antioxidant function of chlorophyll have shown the ability of this phytonutrient to help protect molecules in the body from unwanted oxidation, including fatty acids like linoleic acid.
There are also some studies on the relationship between chlorophyll intake and cancer risk. The animal studies in this area are reasonably extensive and include some different types of cancer, especially colon and liver cancer. Research on chlorophyll and cancer 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 semi-synthetic form of chlorophyll produced in the lab by replacing the magnesium that is naturally present in chlorophyll with copper.)
This early research on chlorophyll and cancer has an interesting dietary connection.
Dietary aflatoxins from moldy grains and legumes represented the cancer-causing agents in these initial human studies. In other words, participants in these early studies
had greater than average risk of liver cancer due to dietary aflatoxin exposure, and this risk was lowered after supplementation with chlorophyllin. Initial results found that damage to DNA by dietary aflatoxin could be decreased by as much as 55% through supplementation with chlorophyllin at 100 milligrams, three times a day, for four months.
Unfortunately, these initial studies—like many subsequent studies—have been conducted using chlorophyllin instead of natural chlorophylls. This semi-synthetic, copper-containing form of chlorophyll has some major differences with naturally occurring chlorophylls like chlorophyll a and chlorophyll b since it is water-soluble rather than fat-soluble. So it is difficult to be sure whether chlorophylls naturally present in food could provide this same level of cancer protection. What is less complicated to determine, however, is the feasibility of getting 100-300 milligrams of chlorophyll per day from your diet. These levels are definitely obtainable. Our Mediterranean Baby Spinach Salad, for example, contains about 100 milligrams of chlorophyll per serving due to its 4-cup spinach content. In other words, these potential cancer protective levels seem realistic to obtain from food.
Risk of colon cancer is the best-researched of the cancer types in relationship to chlorophyll intake. (Other cancer types also studied include liver, skin, and stomach cancer). The best-studied cancer-causing agents in these chlorophyll studies are the polycyclic aromatic hydrocarbons, or PAHs. PAHs can be mutagenic, create unwanted forms of DNA, and initiate tumor development. DBC (dibenzo(def,p)chrysene) is one of the most potent and best studied of the PAH carcinogens. While smoke grilling of food can create dietary PAH exposure, our most common source of exposure to PAHs are car exhaust, tobacco smoke, and coal burning. Chlorophyll is able to form complexes with these PAHs in our digestive tract and prevent their absorption up into the body. This process—called sequestration—is a universally acknowledged mechanism for lowering cancer risk associated with PAH exposure.
An interesting new area of research on chlorophyll involves "chlorophyll metabolites"—namely, chlorophyll-like molecules that can be made from chlorophyll a and chlorophyll b through normal cell metabolism. These molecules include the chlorophyllides (created when the phytol "tail" is removed from chlorophyll), the pheophytins (created when magnesium is removed from chlorophyll), and the pheophorbides (created when both the magnesium and the phytol "tail" is removed). These metabolites of chlorophyll may have health benefits of their own, although the research in this area has yet to clearly show their health benefits. Of special interest in the cooked green vegetable category are metal-containing pheophytins like the zinc pheophytincs and zinc pyropheophytins. Also under investigation in this area are 7-hydroxylmethl chlorophyll, 132-hydroxy-chlorophyll, and 151-hydroxy-lactone-chlorophyll. Our point in mentioning this broad chlorophyll-related family of molecules is to suggest that chlorophyll from our food—especially from green vegetables —may turn out to be more important that previously expected if these many interesting chlorophyll derivatives turn out to have health benefits all their own.