I said a couple of days ago that Australian researchers have found the physiological link between stress and disease. Now, I admit I was a little underimpressed with yet another discovery by medical scientists of the blindingly obvious, but I shouldn't distract from the value of this discovery. So here are some more details. The research is published in the Journal of Experimental Medicine, Volume 202, No. 11, December 5, 2005, pp1-13.

The Garvan Institute scientists have discovered how a hormone, known as neuropeptide Y (NPY), can prevent the immune system from functioning properly. The researchers are rather more excited than I am about its possibilities for paving the way for two new major opportunities for therapeutic intervention, but they can't seem to help their misguided views.

"Most of us expect to come down with a cold or other illness when we are under pressure, but until now we have mostly had circumstantial evidence for a link between the brain and the immune system", says lead Garvan researcher Associate Professor Fabienne Mackay.

"During periods of stress, nerves release a lot of NPY and it gets into the bloodstream, where it directly impacts on the cells in the immune system that look out for and destroy pathogens (bacteria and viruses) in the body," Mackay explains.

This significant discovery came about through a collaboration between Mackay's immunology group and scientists in the Neurobiology programme at the Garvan Institute of Medical Research, Sydney, Australia.

Associate Professor Herbert Herzog who heads the Neurobiology programme says, "Elite athletes are particularly prone to illness, possibly because of the extreme physical and emotional stressors associated with competition. But our research is relevant to everyone because there is no escaping stress - be it in the workplace or at home. Employment surveys show many workers feel there is more job-related stress today than even a couple of years ago." (See, Australian Bureau of Statistics, cat no. 6342.0, Nov 2003, page 4.)

Absenteeism, around 30% of which can be attributed to own ill health or physical disibility, costs well over $10 billion Australian dollars a year, so now more than ever employers should be thinking about how to reduce stress in the hope that their workforce will be healthier. (Based on an absence rate equating to 2% 2004 GDP, as detailed in http://www.racp.edu.au/afom/absenteeism.pdf)

Imagine the combined costs globally on just stress-related absenteeism and you will recognize the potential this line of reaserch may offer. There should be no trouble finding ongoing research and development funding!

The Garvan Institute study centres on two key events that enable our bodies to recognise foreign substances and control invaders. When we encounter a pathogen (bacteria and viruses), the immune ‘sentry' cells that are on guard duty retain and interrogate the suspects. Their activation is made possible by NPY. These cells then return to the lymph nodes, which are found all over the body, with information about the foreign invaders. The lymph nodes are where decisions about defense are made.

In the case of bacteria and viruses, TH1 cells are part of the attack team that is sent out on the 'search and destroy' mission. But when their job is done they need to be turned 'off' and the immune system reset. The same hormone, NPY, that activates the sentry cells now prompts the TH1 cells to slow down and die.

Mackay adds that: "Under normal conditions, circulating immune cells produce small amounts of NPY, which enables the immune cells on sentry duty and the TH1 immune cells to operate - it's a yin and yang kind of situation. But too much NPY means that the TH1 attack is prevented despite the foreign invaders being identified - and this is what happens during stress."

Understanding the connection between NPY and the immune system offers two new major "opportunities for therapeutic intervention", as they put it. This is where the Garvan Institute and I part company. Their approach involves designing new drugs to stimulate immune system defences in people exposed to high levels of stress.

Their second is to exploit this Th1 inhibitory mechanism to prevent immune responses getting out of control as in various inflammatory and autoimmune diseases such as Crohn's disease, rheumatoid arthritis, multiple sclerosis, type I diabetes and lupus. Again, they think this is best done by designing new drugs for the purpose.

My approach is totally different. You see, I actually think people would be better off employing strategies like avoiding high stress situations, developing improved coping and stress management skills, learning healthful ways of removing the biochemistry of stress, such as vigorous physical exercise, eating a stress reducing diet rich in whole-food nutrients (and supplementing when necessary), and adding occasional herbal medicines for short periods when needed.

The fact is, the medical thinking that automatically wants to develop drugs to manipulate natural processes in the body is a real disease risk factor in society. All medical drugs cause some harm and many cause extensive morbidity and death. The wise way forward is to progressively reduce the use and abuse of medical drugs, not to make more.