Few ideas are simple in medicine but none is simpler than the polypill. A combination of five medicines in a single capsule, taken once a day, would be easy to remember, easy to take and, on the strength of the trial reported in today's Lancet, effective.

Could such a simple idea really save hundreds of thousands of lives? Yes. For a simple reason. Although the five medicines that make up the polypill – aspirin, statin and three blood-pressure drugs – are already taken by millions of people in Britain and around the world, there are millions more who ought to be taking them but aren't.

These are the people who are at high risk of heart disease but don't know that they are because they don't have any of the recognised risk factors – being overweight, a smoker, having high blood pressure, high cholesterol or a family history of heart disease.

They lack any of the risk factors but they account for one third of all heart attacks – 80,000 a year in Britain. Yet they are being entirely missed by the current approach which focuses treatment on those identified as being at high risk.

The solution, proposed six years ago by two British specialists in the BMJ, is simple: treat everyone. Give all those over a certain age the polypill whose five constituent medicines are tried and tested and have few side effects. The proposal has been likened to a vaccine for the middle-aged with this difference: unlike a vaccine which might benefit one in 1,000 of those who receive it, the polypill would benefit one in three of those who take it.

But it faces three challenges. First, more evidence is required that it can save lives and funding must be found for the necessary trials to grant it a product licence. The lack of interest from the major companies involved in drug research is an indictment of the profit-based pharmaceutical industry.

Second, it must overcome criticism from some doctors that such a pill could be used as a licence for people to lead unhealthy lifestyles. The fear is that providing cardiovascular protection to everyone in a pill would remove the incentive to stop smoking, go to the gym and eat a healthy diet.

Third, its proponents need to answer critics who say they are encouraging the medicalisation of everyday life. As more and more of us pop pills, there is a question of what effect mass medication would have on our collective psyche. The polypill will save lives – but at what cost?