Scientists Search for Solutions to Stress

As prescription opioid painkillers claim an alarming number of lives every year, researchers are racing to better understand the brain's response to stress, and to identify alternate interventions, speakers said 18 September at AAAS.

Stressful situations — from chronic pain and abuse, to war, or caring for a spouse with dementia — most dramatically affect the physical health of babies, children, and older adults, according to Janice Kiecolt-Glaser, director of The Ohio State University Institute for Behavioral Medicine Research. Fortunately, a growing body of evidence suggests that traditional as well as "complementary" strategies, including meditation, yoga, and increased exercise, can help to mediate the brain's response to stress, said David Shurtleff, deputy director of the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health.

Kiecolt-Glaser and Shurtleff offered insights into the physiological impacts of stress, and science-based efforts to help lessen its negative impacts, as part of a Neuroscience and Society Series organized by AAAS and The Dana Foundation.

Janice Kiecolt-Glaser | AAAS

Long-term, undesirable, and unpredictable forms of stress trigger the release of hormones that can help the body fight off immune-system challenges, yet also, in certain forms, trigger inflammation, Kiecolt-Glaser said. In particular, she has studied how age and stress increase levels of interleukin 6 (IL-6), which can both reduce and promote inflammation. In its pro-inflammatory form, overproduction of IL-6 has been associated with an array of age-related conditions, including cardiovascular disease, osteoporosis, arthritis, type 2 diabetes, certain cancers, periodontal disease, and overall decline in health, she noted. To make matters worse, stress and depression fuel inflammation, which triggers the body's immune-system responses, further increasing levels of IL-6.

In a six-year study of older people who were caring for spouses with Alzheimer's Disease, caregivers had a 63% higher death rate than non-caregivers, Kiecolt-Glaser said. Compared with non-caregivers, those caring for a spouse also had a four-fold increase in IL-6. Other studies have shown that stress can slow wound healing, prolong infections, interfere with vaccine responses, and even shorten telomeres — the bits of DNA on the ends of chromosomes that play a role in aging, by regulating the lifespan of cells.

Physical activity "is one of the best things we know" to combat the effects of stress, Kiecolt-Glaser said. Getting sufficient sleep and eating well can also help, but unfortunately, "most people when they're stressed don't reach for broccoli … unless it's covered with Hollandaise sauce," she said. In fact, research has shown that people who experience stressful events and then eat high-fat meals tend to metabolize those calories less effectively. Once a person becomes stressed and depressed, her body creates more pro-inflammatory hormones such as IL-6, making her more depressed, in a vicious cycle, Kiecolt-Glaser explained.

Shurtleff's Center, established in 1998, supports fundamental studies of the usefulness and safety of complementary interventions to help those suffering from too much stress. In 2007, Shurtleff noted, 40% of U.S. adults and 12% of children "used some type of complementary approach," spending a total of $34 billion — about 1% of the country's total health-care expenditures — on natural products and activities such as massage, acupuncture, tai chi, hypnosis, and biofeedback.

Research supported by the National Center for Complementary and Alternative Medicine (NCCAM) is helping to inform consumers: In 2002, Shurtleff said, among those Americans who used natural products during the previous year, 40% were stocking up on echinacea — until research showed that the flower extract does not reduce the length or severity of colds that adults catch. By comparison, some research has shown that fish oil/omega-3 may be effective in promoting good health, especially as a way to possibly help reduce the risk of heart disease. Although these data are "mixed" and additional trials are needed to confirm the findings, by 2007 more than one-third of all U.S. consumers who reported using natural products in the previous month were reaching for fish oil/omega-3, while fewer were buying echinacea. NCCAM's work has also shown that ginkgo biloba does not prevent dementia in older adults, and St. John's wort is ineffective for combating major depression of moderate severity, Shurtleff said.

"If you're using supplements," he added, "talk to your doctor," particularly about any potential interactions with traditional medicines. On the horizon, Center staff are eager to learn more about the potential of probiotics — organisms such as bacteria or yeast that interact with the gut microbiota, the immune system, and the brain.

To better guide consumers, the Center also strives to evaluate the impacts of mind and body practices such yoga, through reproducible studies. Shurtleff said that practices such as meditation can actually alter brain activity, tamping down fear-based, habitual responses to stress.

Video of the full event. | AAAS/Dana Foundation

Further research into alternative, or complementary ways to help people manage stress and chronic pain will be essential; in 2010, strong painkillers called opioid analgesics— perhaps better known by brand names such as OxyContin and Vicodin — caused 16,651 deaths in the United States, accounting for 3 of every 4 pharmaceutical overdose deaths that year, according to the Centers for Disease Control and Prevention (CDC). U.S. drug overdose death rates have "more than tripled since 1990 and have never been higher," the CDC reported, adding that "there is currently a growing, deadly epidemic of prescription painkiller abuse."

Pain modulates emotion and cognition, causing sufferers to become anxious. Research by the NCCAM is focusing on how people can strengthen their response to stress and pain, Shurtleff said, "so maybe you won't have to reach for that opioid medication."

The Center maintains an extensive alphabetical guide to health topics that spells out, from acai to zinc, what science has told us so far about a wide range of natural products and mind and body practices.