Q. I keep hearing about the danger of parabens in cosmetics. What are these, and why are they bad?

A. Parabens, used as pharmaceutical preservatives, became popular in the cosmetics industry because of their broad-spectrum antibacterial properties. They’re listed on ingredient labels with the prefixes methyl, ethyl, propyl, or butyl.

Manufacturers especially like parabens because they are stable and inexpensive, and at one time were considered safe. But in 1998, British researchers at Brunel University discovered that parabens mimic estrogen. Since then, studies have linked paraben exposure to low sperm counts and decreased testosterone levels in men. In a recent study of women, researchers found high concentrations of parabens in breast tumors, leading them to speculate that the parabens came from products routinely applied to the skin. Like most hormone-disrupting chemicals, parabens accumulate in the body’s fatty tissue.

Despite the mounting evidence of parabens’ darker side, most manufacturers continue to add them to conventional cosmetic and personal care products. Natural cosmetic companies, however, have found some effective alternatives. A growing number of chemical-free cosmetic and personal care items are now preserved with safe, nontoxic compounds. Look for products that use natural antioxidants such as vitamin E instead of parabens.

This Ask the Expert was written by Kim Erickson, an herbalist, health writer, and the author of Drop-Dead Gorgeous (Contemporary, 2002).

Q. How can I use breathing to manage stress?

A. Deep breathing can help ward off daily stress and tension by ensuring a sufficient amount of oxygen is in the body. At the first signs of stress, take a few moments to practice these essential relaxation steps from The Chronic Pain Control Workbook by Ellen Mohr Catalano, et al (Harbinger, 1996). Close your eyes and focus on taking five or six breaths. Try to make each breath slower and deeper as you go along, while staying true to your natural rhythm and not forcing your breath to be a certain way. Allow yourself to relax and watch extraneous thoughts pass through your mind; observe them and let them go.

The practice of deep breathing is that easy, and the beauty is you can use the technique anywhere, anytime, whether you’re sitting in your office or standing in the grocery-store line. There are no contraindications, so you can do deep breathing as many times as you need during the day.

This Ask the Expert was written by Victoria Shanta Retelny, RD, LD, a freelance writer who also practices medical nutrition therapy at the Northwestern Memorial Hospital Wellness Institute in Chicago.