Women, Asthma and the Brain

There’s been a longstanding puzzle in medicine. Well actually there are lots of them, but here’s one that may be a puzzle no more.

For many years now, it’s been known that asthma is more common in women, and also that psychological stress can cause flare ups of asthma.

Many women experience “menstrual flaring:” a worsening of asthma around the time of their menstrual period. There is also a strange paradox: some women with asthma wheeze less if they take an oral contraceptive, while some non-asthmatic women begin to wheeze when they take it. In some women pregnancy makes asthma worse, and in others it affords months of relief of symptoms. Women who are obese are more likely to get asthma, presumably because their intra-abdominal fat stores are churning out inflammatory mediators.

Researchers from the University of Wisconsin have shed  some important light on this link between asthma and the brain. In research published in the Proceedings of the National Academy of Sciences. In the study, six patients with mild asthma were exposed to ragweed or dust-mite extracts. The subjects were shown three different categories of words: asthma-related (e.g., "wheeze"), non-asthma negative ("loneliness") or neutral ("curtains").

Using functional magnetic resonance imaging, they showed that activity in two regions, known as the anterior cingulate cortex and the insula showed increased activity when the asthma-related words were heard compared with the other types. What is more, this enhanced activity was specifically linked to physiologic signals from the ragweed and dust-mite extracts. So being exposed to asthma-relevant emotional stimuli is associated with markers of inflammation and airway obstruction in asthmatic people exposed to an asthma-producing antigen.

In people with asthma and other stress-related conditions, these brain regions may be hyper-responsive to disease-specific emotional and physiologic signals. Taken together, these could contribute to problems that worsen the asthma, such as inflammation.

And one of the ways of making these regions of the brain hyper-responsive? Bathe them in estrogen.

That still does not explain why pregnancy and the oral contraceptive makes some women’s asthma better, and does the opposite in others. But it may just have to do with the “set point” of the cells in these regions of the brain. In the same way that we might set the thermostat in out house. An already hyper-responsive brain might be normalized and an under-active one stimulated to be over-active.

We need to do some more experiments, but these are a great start.

If you ever wheeze, have a look to see if there are stressors or hormonal events that trigger you. Whether you are being treated with homeopathy, herbals or conventional therapy, knowing when to expect trouble gives you the power to adapt you treatment when you are entering a risky time in your life.