Eighteen years ago, my genial Irish family doctor saved my life. Dropping in to discuss a puzzling neurological complaint, he seized the opportunity to take my blood pressure, which to his, and my, great surprise proved to be alarmingly high. So high, in fact, that I had a 99 per cent chance of a potentially fatal stroke or coronary by the time I was 65 years old.

Almost two decades on, popping my blood pressure-lowering pills every morning has become something of a holy ritual; so secure a guarantee of my present and future health that I feel distinctly uneasy if I omit to take them.

Since then, the number of prescriptions for these life-saving drugs has increased tenfold, extending their benefits beyond the minority (like myself), whose blood pressure is markedly elevated, to the millions more with "mild" hypertension.

The same trend is apparent with drugs to lower the blood sugar (a fourfold rise) and cholesterol (a whopping twentyfold). And this must be, one would suppose, a good thing. Still, in medicine as in life, too much of a good thing can be bad for you. There is no pill that will not cause adverse effects in some. The difficulty for those taking many pills (polypharmacy) is that those adverse effects tend to be much more insidious - a combination of muscular aches and pains, lethargy, insomnia, poor concentration and so on - readily misattributed, by doctors and patients alike, to "getting on a bit".

The scale of this hidden epidemic of polypharmacy-induced decrepitude might have gone unappreciated were it not for all those readers of this column who, over the years, have written to tell of the almost miraculous recovery in their health and wellbeing on reducing or stopping, for some reason or another, their pills. Their accounts in turn had a multiplier effect, prompting others to describe a similarly felicitous outcome.

To be sure, the relevant clinical trials claim these drugs reduce the risk of heart attack or stroke by around 20 per cent in those whose physiological measurements are modestly raised; reason enough for doctors to prescribe them. But the absolute benefit for the individual turns out to be minuscule, of the order of between 1 and 2 per cent - or perhaps even less.

The devastating consequences of this statistical alchemy that portrays these drugs as being so much more effective than is actually the case are apparent in the trend, recently reported in this paper, of the decline in life expectancy with an "additional" 30,000 deaths in the first four months of this year alone. Polypharmacy may not be the sole explanation for it but, given the almost doubling of emergency hospital admissions for serious side-effects of drugs in the recent past, it is almost certainly a contributory factor.

Nine out of 10 GPs now acknowledge they prescribe "too many pills", yet mass medication remains deeply entrenched within mainstream medical practice. The only way out of this grievous situation, I argue in my new book, Too Many Pills, is for the public to take the initiative by acquainting themselves with the merits (or otherwise) of the drugs they are taking, and have a properly informed discussion with their doctors on whether they really need to keep popping the pills.