Milkweed: From Floss to Fun in the Sun
Milkweed is a favorite food of monarch butterfly caterpillars, which also store the plant's poisons for protection from birds and other predators. Farmers haven't always looked kindly upon milkweed, though. That's because large numbers of these plants can creep into farmers' fields, competing with crops for water, sunlight, and nutrients.
But some farmers today are changing their minds. Now, rather than getting rid of milkweed, the farmers actually grow it as a crop. They've learned that milkweed's soft, silky floss (fibers) can be used to stuff pillows, comforters and jacket linings.
But floss isn't the only usable portion of this native American plant. Oil from its flat orange seeds can also be turned into ingredients for natural sunscreens, says Rogers Harry-O'kuru. He's a chemist with the Agricultural Research Service (ARS) in Peoria, Illinois.
Harry-O'kuru has been experimenting with sunscreen formulas containing oil from common milkweed. Its scientific name is Asclepias syriaca, and it grows throughout much of the United States.
Harry-O'kuru examined the milkweed oil's fats and waxes and decided they would make great starter ingredients for not only sunscreens, but also cosmetics, moisturizers, conditioners, and other skin- and hair-care products.
Many of today's sunscreens use chemical absorbers or blocks to protect our skin from two kinds of ultraviolet (UV) radiation from the sun: UV-A and UV-B.
Harm caused by UV-B radiation is temporary, like the sunburn a careless beachgoer might get while on vacation. UV-A radiation causes long-term harm, such as early aging of skin and skin cancers. Lifeguards, construction crews and others who spend a lot of time outdoors are at greatest risk.
Harry-O'kuru's milkweed-oil formula uses natural ingredients called antioxidants [pronounced ANT-ee-OX-eee-dunts]. The antioxidants soak up the sun's harmful rays before they reach our skin. In laboratory tests, the antioxidants in the formula blocked UV rays as well as certain rub-on sunscreens now sold.
Harry-O'kuru hopes milkweed-oil-based suncreens will be more Earth-friendly, too, thanks to their fats and waxes, which rapidly break down in the environment.
Besides sunscreen lotions, the milkweed-oil formula may also be useful ingredients in epoxies, paints, and other industrial products.
If farmers change their mind about milkweed, maybe industry will, too. "Right now," says Harry-O'kuru, "we're hoping a commercial partner will become interested in developing the technology further."
By Jan Suszkiw, Agricultural Research Service, Information Staff