As if we weren't already obsessed enough with our modern-day ailments - some of them newly created by pharmaceutical giants eager to find new uses for old drugs (was there such a thing as female sexual dysfunction before Viagra's makers needed a new market for sexual insecurity?).

Now every sneeze, every wheezy breath we take is the focus of paranoid attention.

The last time a pandemic loomed, friends of mine spent several hundred dollars arming themselves with Tamiflu. It seemed like a lot of money, so I crossed my fingers instead.

Now that we have the part swine, part bird, part human H1N1 virus in our midst, my family's pandemic plan has been upgraded to include the consumption of liberal amounts of garlic (also good for keeping potentially infectious people at bay), lessons on correct sneezing methodology (into a tissue or the crook of your elbow) and a lot of hand-washing.

As it happens, this is about as good as prevention gets, according to the authoritative Cochrane Library.

The Cochrane Library is an international non-profit collaboration of academics that reviews all the evidence on a given question and boils it down to a plain English summary. This is helpful given an estimated 15 million medical academic articles have been published to date, and 5000 journals are published every month.

For example, is Vitamin C any good for preventing and treating the common cold? Not according to a Cochrane review of the evidence, though taking it can help during times of intense stress.

Cochrane's advice on influenza (which in New Zealand is estimated to cause around 400 deaths a year) and the H1N1 virus is that the most effective preventive interventions are "non-pharmacological".

As researcher Tom Jefferson has said, the interventions which work best against influenza and all respiratory viruses are the simple, low-cost ones - "but because there is no pharmaceutical market for these they're very rarely promoted". They're things like personal hygiene, hand-washing and keeping one's distance from the infectious.

Which is comforting considering there won't be enough Tamiflu and vaccine to go around if this turns out to be worse than it looks. Not that the Cochrane reviews inspire total confidence in the effectiveness of Tamiflu (which will speed your recovery by all of 16 or 17 hours) or the "not very effective" flu vaccines.

The popular natural health website is more or less of the same mind. Your best defence, it says, is to eat right, get lots of sleep, avoid sugar and stress, load up on garlic, Vitamin D and krill oil - and wash your hands. It seems almost too simple. We're in love with pharmacological fixes, and the more expensive and complicated it is, the more certain we are of its effectiveness.

Belief, as it turns out, is important in healing. It's a myth that we use only 10 per cent of our brains, but few would dispute the power of the mind over the body and the significance that has for good health.

As Mark Twain once said: "The power which a man's imagination has over his body to heal it or make it sick is a force which none of us are born without."

A survey published in the latest edition of the New Zealand Medical Journal which shows that three out of four doctors have prescribed placebo medications to their patients, half of those in the previous year, is both a testament to our propensity for seeking solutions in pills and the phenomena known as "the placebo effect".

Leaving aside the questionable ethics of doctors lying to their patients and the harm done by the unnecessary prescribing of antibiotics (which the survey found), what does this say about modern medicine?

Placebos are treatments that have no demonstrated clinical efficacy. They shouldn't work, and yet an abundance of anecdotal evidence and data suggest otherwise.

Famous examples include Henry Beecher, a Harvard professor of anaesthesiology, who wrote about operating on a soldier with horrific injuries in a World War II field hospital, using salt water because he'd run out of morphine.

Others include pain relief from both acupuncture and sham acupuncture, reduced pain and swelling in dental patients from sham ultrasound and placebo operations that seemed to alleviate knee pain and even improve angina.

As with anaesthesia (the exact workings of which are still largely a mystery), no one knows exactly how the placebo effect works, although neurologists in one study have shown that patients given a placebo released as much dopamine as those who got the active drug. Daniel Moerman found that placebo treatment of sugar pills not only healed ulcers in placebo-controlled trials of gastric ulcer medication, but that four sugar pills were better than two.

Moerman showed that the placebo effect is culturally specific - it's shaped by "the meanings patients attribute to their illnesses and to the treatments they receive".

That's why medical students given red and blue sugar pills in one study generally reported that the red pills acted as stimulants and the blue ones as depressants - and that two pills were more effective than one; why heavily-advertised and flashily-packaged brand name aspirin was found to be more effective than a generic version; and why placebo delivered through salt-water injections has been shown to be more effective than sugar pills.

Ceremony and ritual matter, as do the beliefs and attitudes of both doctor and patient. Treatment handed out with conviction and a positive message engenders less fear, less anxiety and less pain.

The power of the placebo effect isn't in the pills, of course. It's in our heads - in our emotional and cultural worlds, and in the relationship between our minds and bodies, which modern medicine has largely neglected.