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Brain study links negative emotions and lowered immunity

People with brain activity linked to sad emotions develop fewer antibodies when given a flu vaccination. Brain activity linking negative emotions to a lower immune response against disease has been revealed for the first time, claim researchers.

Many previous studies have shown that emotions and stress can adversely affect the immune system. But this effect had not been directly correlated with activity in the brain, says study leader Richard Davidson, at the University of Wisconsin, Madison, in the US.

The part of the brain the team studied, the prefrontal cortex (PFC), is associated with depression. People who had the greatest activity in the right PFC when asked to dwell on distressing episodes in their life had a markedly lower antibody levels after an influenza vaccination. In contrast, those showing exceptional activity in the left PFC when recalling happy times developed high antibody levels.

Davidson says emotions play an important role in regulating systems in the body that influence health. "This study establishes that people with a pattern of brain activity that has been associated with positive [emotions] are also the ones to show the best response to the flu vaccine."

"It begins to suggest a mechanism for why subjects with a more positive emotional disposition may be healthier," he says. Janice Kiecolt-Glaser, an expert on stress and immunity at Ohio State University, told the New York Times that the study represents "some of the best evidence we've seen to date."

Intense sadness

Davidson, with colleagues at Wisconsin and Princeton University, New Jersey, asked 52 men and women who graduated from Wisconsin in 1957 to recount both the best and worst events in their lives on paper.

For their best experiences, the subjects were asked to write about an event where they experienced "intense happiness or joy". And for their worst experience they were asked to remember an event causing "the most intense sadness, fear, or anger".

During this autobiographical task, the electrical activity of the brain was measured. The subjects were then given flu shots and their antibody levels were measured after two weeks, four weeks and six months. The researcher found a clear link between strong activity in the left PFC and a large rise in antibodies, and vice versa. (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1534743100).

However, the study could not explain exactly how having a positive attitude boosts the immune system. The researchers say some evidence exists to suggest a link between the PFC and the immune system via a complex hormonal system governed by the hypothalamic, pituitary and adrenal glands.

Original Post
Angry kids at greater risk of Heart Disease
23:00 18 May 03 news service

Hostile children are up to three times more prone to key risk factors leading to cardiovascular disease than more serene kids, suggests a new study.

Researchers found that children scoring highly on standard tests for hostility were more likely to have developed "metabolic syndrome" when re-tested three years later. Metabolic syndrome is a collection of risk factors like obesity, insulin resistance and high blood pressure, which together can lead to heart disease or diabetes.

"The hostility seemed to precede metabolic syndrome," says Kristen Salomon, a psychologist, now at the University of South Florida in Tampa, Florida. She notes that the cardiovascular disease process is known to start very early in life and that hostility also shows up early.

Salomon told New Scientist: "Parents should be aware of what their kids eat and how much exercise they take, but it is also important to focus on psychological factors and treat these early on."

"This is a small study," says Fiona Kirkwood, a cardiac nurse adviser to the British Heart Foundation. "But it is consistent with some adult studies indicating that hostility may be associated with obesity and insulin resistance, which are part of metabolic syndrome."

Type A personality

Certain personality types have long been associated with heart disease in adults. In the 1970s, a so-called "type A personality" - exhibited by time-pressured, success-orientated, hostile perfectionists - was linked to heart disease. But recent research shows that only the hostility component is a factor, says Salomon.

Hostility has three main facets. There is a cognitive component that reflects an untrusting and cynical view of the world. Hostile emotional responses result in people feeling more angry. And hostile people tend to be more aggressive when provoked or challenged.

The team, based at the University of Pittsburgh, Pennsylvania, and the University of Helsinki, Finland, studied 134 children aged 8 to 10 and 15 to 17. Physiological parameters like blood pressure were recorded and children then completed a standard hostility questionnaire.

Their behavioural responses were also tested in a standardised "type-A" interview. In these, for example, the interviewer deliberately cuts short a child while he or she is replying to a question. A hostile reaction could include the child raising their voice or making snide remarks.

Repeating the same tests three years later revealed that the most hostile children were three times more likely to have developed metabolic syndrome.

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