Here are some of the most recently found links between emotional and physical health:
Chronic stress ages human cells. Scientists at the University of California, San Francisco, compared the mothers of healthy children with the mothers of chronically ill children. Their report, published last December in the Proceedings of the National Academy of Sciences, found the stress of caring for a sick child causes cellular changes. The stressed women's cells had shorter telomeres, which are bits of DNA found at the end of chromosomes. Telomeres shorten slightly each time a cell divides; as a result, they're much shorter in older people. The telomeres of the most stressed participants had cells that appeared about 10 years older than the women were chronologically; the cells also had lower levels of an enzyme that repairs damaged telomeres, and higher levels of free radicals, which can damage DNA.
Psychological tension may speed the onset of cancer. In a study at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, mice were exposed to a psychologically stressful situation--the smell of fox urine--along with large amounts of ultraviolet light. The results, published in the December 2004 Journal of the American Academy of Dermatology, found that the mice developed skin cancers more than twice as fast as mice exposed to only the UV light. The researchers suggested humans could have a similar response.
Disturbing emotions can cause physical damage. Researchers at the University of California, Los Angeles, asked one group of college students to write about an upsetting experience that made them feel bad about themselves, while a second group of students wrote about neutral topics. The study, published in Psychosomatic Medicine, determined the first group secreted greater amounts of a marker of pro-inflammatory activity than the second group. The more shame and anxiety the participants felt, the more of this inflammatory marker their bodies produced.
Patient confidence boosts treatment results. In a recent study published in the journal Prevention & Treatment, Italian researchers administered pain medicine to two sets of people: those who knew they were receiving a potent treatment and those who received the treatment without their knowledge. The same medication ended up being more effective in the aware patients.
These are the kinds of findings Pert has in mind when she says emotions "run every system in our bodies." Stress, anxiety, depression, and other difficult feelings dampen the immune system. So what started as an odd experiment with rats and artificial sweetener has grown into a whole new way of looking at human health. Says Ader: "The field has burgeoned beyond what anyone would have expected."
Emotions are double-edged swords. They allow us to fully experience our humanity, but they also impact our immune systems. That means we need a new definition of wellness. Because the mind and body are essentially one, relieving stress, letting go of anger, and finding productive ways to cope with the difficulties of life may be as important to our health as nutrition, exercise, and all the other steps we take to keep our bodies healthy.