Tuesday, February 22, 2005


The parabens, methyl-, propyl-, and parahydroxybenzoate, are the most commonly used preservatives in the United States. An estimated 75 to 90 percent of cosmetics parabens including shampoos, make-up, lotions, and deodorants baby lotions, and sunscreens contain parabens. Water is the only ingredient used more frequently in cosmetics. The parabens have a broad spectrum of antimicrobial activity, were believed to be safe to use, they are relatively nonirritating, nonsensitizing, and nonpoisonous-are stable in acidic or alkaline cosmetics, and are sufficiently soluble in water to be effective in liquids. The typical paraben preservative system contains 0.2 percent methyl- and 0.1 percent propylparaben. In 2004, there was a blip in concern, when a study published in the Journal of Applied Toxicology reported parabens may play a part in breast cancer. British researchers found traces of it in 20 women who had breast tumors. The parabens are believed to act like the female hormone estrogen. There were a number of earlier reports in the scientific literature that expressed concern at the connection between parabens and breast cancer, particularly in underarm deodorants. British researcher, Dr. P.W Harvey, for example, noted in the Journal of Applied Toxicology a year earlier,it was interesting certain parabens lacked activity when swallowed but were clearly active on the skin. Harvey wrote:"This was of "some relevance to the use of underarm cosmetics." He called for further work to establish whether or not the use of underarm cosmetics (particularly containing estrogenic formulas) contributes to the rising incidence of breast cancer. It would seem prudent to conduct this work because the current database is sparse and the effects of long-term low-level exposures to weakly estrogenic chemicals on human health, particularly their application to the underarm and the risks of breast cancer, are unknown.

What about men? It was previously shown that exposure of post-weaning rats and mice to butyl or propyl parabens adversely affects the secretion of testosterone and the function of the male reproductive system. In a study of mice by researchers at the Tokyo Metropolitan Institute of Public Health last November in Food and Chemical Toxicology ( 42(11):1845-9, it was reported that methyl and ethyl parabens do not adversely affect the secretion of sex hormones or the male rats' reproductive function.

The Canadian Department of Health has put parabens on its "Hot list". If a hotlist chemical appears on a label, it is flagged in Health Canada's Cosmetic Notification System (CNS) and the manufacturer is sent a letter of "Canadian Cosmetics Safety Programme's (cq) concern".

The connection between the estrogenic effects of the parabens and humans has faded from press attention today. Since parabens are so widely used in cosmetics, should you be concerned?

While there is no evidence that parabens directly cause cancer, Harvey pointed out in 2004: The hypothesis that underarm cosmetics may contribute to the incidence of breast cancer has obvious implications, not least because of the size of the population potentially exposed… The use of underarm cosmetics presents a special case because of the direct application of the compounds to skin."

Thursday, February 17, 2005


The sharks' immune systems are different from humans' and shark derivatives are now under intensive study. Squalamine, derived from sharks, is a unique compound that kills a variety of bacteria, fungi, and parasites. Shark cartilage has been used in alternative medicine as an anti-cancer and anti-AIDS compound because sharks apparently do not suffer from cancer. Mainstream medical researchers, who once thought the shark products were merely the "patent medicines" of human "sharks", are now investigating those marine carnivorous fishes' derivatives for their potential in the treatment of a number of human ills.

Enrollment is now underway by Genaera Corporation, a biopharmaceutical headquartered in Plymouth Meeting, Pennsylvania, according to the FDANews Drug Pipeline Alert, to test the efficacy of squalamine in treating "wet" age-related macular degeneration (AMD.Macular degeneration affects approximately 20 percent of Americans aged 65 and older and is a leading cause of blindness. The macular is the center of the retina, the light receptor in the eye. The first symptoms usually are loss of central visual acuity or visual distortion in one eye. The wet type of macular degeneration is caused by the growth of abnormal blood vessels behind the macula. The abnormal blood vessels tend to hemorrhage or leak, resulting in the formation of scar tissue .No medical therapy, thus far, has proven effective.

Squalamine is the leading anti-angiogenic drug being developed to treat AMD. Angiogenesis is a word that comes from combining the two Greek words angio, meaning "blood vessel," and genesis, meaning "beginning." Angiogenesis is the creation of tiny new blood vessels. Normally, angiogenesis is a healthy process. New blood vessels develop, for instance, to help your body heal cuts and other wounds. But with AMD the same process creates new, very small blood vessels that damage the macula in the eye. Antiangiogenesis treatment is the use of drugs or other substances to stop the development of macula damaging new blood vessels. Such treatments are believed to also be applicable to certain tumors. Without a blood supply, tumors can't grow.

Incidentally, while shark skin is not pleasant to touch, the oil from its liver oil is a rich source of vitamin A and is now being used in cosmetic lubricating creams and lotions.

For further information about Genaera's AMD research, check http://www.genaera.com/about.html

Wednesday, February 16, 2005

There's More To The FDA Than Drugs

The newly appointed veterinarian who heads the Food and Drug Adminstration, Dr. Lester Crawford, will have a lot to swallow. While the press is full of side-effects caused by prescription drugs, the food supply is a bigger problem. Not everyone takes pills but everyone eats. We want fresh strawberries in winter and tomatoes all year round yet we have replaced many of our farms with housing and roadways and our edibles are increasingly being grown in other countries. Only a tiny fraction of the food that enters our ports is checked by our guardian agencies. Not only do we have to worry about foreign foods with undersirable additives and residues, we now have to be protected against terrorists tampering. The FDA's ability to protect the 400,000 domestic and foreign facilities that deal with food within our country is almost impossible because it is understaffed, overworked and short of funds. As far as ingredients added to our food domestically, manufacturers do not have to petition for affirmation that an additive is Generally Recognized As Safe (GRAS), they simply have to have to notify the FDA of their additive's GRAS status and provide some evidence to support it. The FDA says that letting the manufacturers determine what is GRAS and making it simpler to obtain FDA approval allows the FDA to "gain increased awareness of ingredients in the nation's food supply and the cumulative dietary exposure to GRAS substances," and, of course, save money. Most of the additives are safe if unnecessary. They are added to intrigue us to buy and to preserve shelf-life.
They are chemicals, however, and how do they interact with the chemicals everyone is worrying about in our medicine chests? Have a question about a particular ingredient? Send it along.