Sunday, November 21, 2010

Life Lines 46


I got a call from a neighbor who was a teacher of two of our children and who was a student in one of my classes. She told me of her efforts to track down a rumor that the strawberry color in one of her favorite foods was made from bugs. I immediately thought of the dye called carmine. It was familiar to me because years ago when reading about the history of dyes used for microscopy, I read about the first dye to be used in 1857 by a German anatomist named Joseph von Gerlach. He discovered that he could dye cells with acetocarmine. Within the next twenty years German scientists were using both natural dyes and artificial dyes to work out microscopic anatomy. I recall the course I had at NYU as an undergraduate preparing my own slides with synthetic, mostly aniline, dyes like eosin and hemotoxylin. Later I prepared fruit fly salivary gland squashes using acetocarmine.

Carmine dye is obtained from an insect that feeds on cactus. It is a hemipteran bug Dactylopius coccus and the Aztecs were using it when the Spanish arrived. They sent back the dye (called carmine) to Europe where it was widely used in the clothing industry. The British Red Coats in our Revolutionary War were dyed with carmine. The insects are scraped off the cactus and then dried and pulverized and the red dye extracted.
Today virtually all clothing is dyed red with aniline dyes. We like to have a bright red color for our meats and for the various fruit fillings, puddings, yoghurts, and other foods with strawberries or raspberries in them. Unfortunately natural red coloring of these meats and fruits tend to fade and in countries like Georgia in the Caucasian Mountains, where I once visited, the meat looks grey or a faded red. To Americans used to supermarket cheerful solid colors for their food, it looks repulsive. Hence much of our foods are dyed to look as we want them to look. But many people also prefer the organic and the natural to the artificial, so manufacturers try to oblige with natural dyes. But we consider eating insects repulsive so our manufacturers using natural products list the item as “carmine” instead of “bugs” in their contents. It’s a no win situation because some of the artificial aniline dyes are potent carcinogens and they have been banned for many years. Imagine how difficult it is for the food perfectionist to track down what is in food. Would a kosher Jew eat a dairy product that contained carmine as a dye? Probably not, because hemipteran bugs do not fall in the category of approved bugs (hind legs taller than the other legs, like grasshoppers) in the Bible. Would a strict vegetarian eat a fruit dessert that contained carmine? Probably not, if that person knew carmine was prepared by pulverizing thousands of cochineal bugs to extract the dye. One might get around this by making carmine synthetically but I have no idea how purists would respond to that—it may still be unnatural and not kosher to experts assessing these products.

Food is almost never free of products we should avoid or that for ideological or religious reasons we are taught to avoid. Some mushroom species have very high levels of mutagens. Some cereal grains and nuts get infected with fungi that produce carcinogens. Organic foods are more likely than treated foods to experience that. But the treatment to prevent spoilage may itself contain carcinogenic additives. After all, how does the sprayed agent kill the fungi you want to avoid? If it damages the DNA of the fungi isn’t it plausible it could damage your DNA?

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