• Nationwide herbal and botanical supplement sales totaled $4.8 billion in 2007, when the recession began, up 4.3 percent over 2006. That was a marginally higher increase compared with the previous year, according to Jason Phillips of the Nutrition Business Journal, an industry-tracking publication. Sales of animal oil supplements — mostly fish oils — were up 29 percent from 2006. While that was a decline from the previous year, both categories continued to show strong growth in a faltering economy.

• A government survey released in December said concerns about the cost of conventional medicine influenced Americans' decisions to try alternative remedies. "Nonvitamin, nonmineral natural products," including fish oil and herbal medicines, were the most commonly used alternatives, taken by almost 18 percent of Americans in 2007, the report said. Among those users, roughly a quarter said they delayed or didn't get conventional medical care because of the cost.

Report co-author Richard Nahin of the National Institutes of Health's National Center for Complementary and Alternative Medicine offered cautionary advice on the topic.

People taking herbal and other supplements should let their doctor know what they're using, Nahin said.

Supplements and other alternative treatments don't require rigorous testing and government approval. They also can interfere with prescription drugs, and combined, can be life-threatening in rare cases, Nahin said.

His agency also conducts its own research on alternative medicine and offers information about some of the most popular products at its Web site, www.nccam.nih.gov.

For example, echinacea is sometimes used for colds and flu. The agency Web site says evidence is mixed on whether it is effective, although one rigorous federally funded study found the herb worked no better against colds than placebo treatment. Echinacea can cause gastrointestinal upsets and allergic symptoms in people with ragweed allergies, the NIH site notes.

Valerian, the herb the Birleffis have used for insomnia, has been shown in some studies to help people sleep better, but evidence from well-designed research is lacking, the agency says. Using it for several weeks is generally thought to be safe, but long-term effects are unknown.

There's scant Western research on fritillary bulb remedies, the ancient Chinese herbal medicine that the Kemp family uses for colds. A test sample examined in a recent Chinese study found elevated amounts of cadmium, a heavy metal linked with cancer.