Medical Matters: Life expectancy in Western countries has been slowly increasing since records began in the mid-19th century. Life expectancy at birth was about 40 years at that time. During the next century or more there was a gradual fall in infant mortality. That trend has increased more dramatically since the World War and particularly during the past 30 years.
This greater decline in mortality can be attributed to the recent improvement in the health and longevity of middle aged and older men and women. This is evident in Ireland today with women reaching a life expectancy of 80 years and men reaching over 75 years. These changes in Ireland are reflected in other Western countries.
The greatest decline is in coronary disease, stroke, respiratory disease, lung cancer in men and in stomach cancer - coronary disease has declined in men in seven countries, including Ireland, in 1970-1999 and since 1999 there has been a further decline in mortality of 32 per cent in both sexes up to and including 2004.
It is tempting to attribute this dramatic improvement in mortality to better medical services, but research findings in various countries, including Ireland, Scotland, England, New Zealand, Finland and the US, provide compelling evidence that this dramatic change in life expectancy can be attributed mostly to changes in lifestyle among Western people rather than to medical intervention.
Because coronary disease was the most frequent cause of high mortality, this research was based on the factors which were most likely to affect the incidence and mortality from this heart condition, although the same factors to varying degrees may be important in causing the other common chronic diseases.
In my own sphere of cardiology, there can be little doubt about the dominant role of prevention in the achievement of a healthy society. Thanks largely to preventive measures in relation to smoking, healthy eating and blood pressure control, the coronary epidemic, which peaked in the late 1960s and early 1970s in Ireland and the UK, has shown a dramatic mortality decline. The decline is most evident in the younger age groups. This led to a drop of about 62 per cent in men and 45 per cent in women, an estimated saving of 68,230 deaths in the UK in 2000. This is confirmed in a study published in 2004 which attributed 48 per cent of the decline to reduced cigarette smoking, 9.5 per cent to blood control and 9.5 per cent to lowered cholesterol levels.
The population reduction in high blood pressure in Britain was attributed in another study to lifestyle change rather than medication.
Some 42 per cent of the decline in coronary mortality was attributed to treatment including risk factor intervention and treatment after a heart attack, treatment of heart failure and to coronary care. Only 3.5 per cent was attributed to heart surgery and angioplasty combined. Small adverse effects were attributed to reduced exercise, increasing obesity and diabetes - three less desirable trends which are evident in Western society and which are now at the basis of the obesity syndrome.
In Ireland the rates of decline in mortality from coronary heart disease are similar to those in Britain. A study from St James's Hospital in Dublin reports the same findings among the Irish population where the decline was 47 per cent in 1985-2000 with an estimated saving of 3,800 lives. Again 48 per cent of the decline was attributed to the sharp fall in cigarette smoking among the middle aged.
The dominant influence of lifestyle in reducing coronary mortality has been confirmed in the US with a decline of 57 per cent in 1980-1990; in New Zealand with a reduction in 1982-1993 of 52 per cent, and in Scotland with a reduction of 57 per cent from 1975-1994. Similar findings are reported from Finland, the country which had the highest mortality in the world in the late 1960s and which was a leader in attacking the causes of coronary heart disease.
There is little doubt that treatment of the established disease has improved during these recent times but lifestyle changes are also being adopted more widely. Such changes have made the greatest contribution to the decline and at a fraction of the cost to society.
There is little doubt that heart surgery and angioplasty have limited value in management, at least in patients with chronic coronary disease, although these interventions may appear more important because of the perception that immediate invasive treatment appears more effective than more conservative management and changes in behaviour.
What does emerge is that the common diseases which are induced by an insalubrious lifestyle are less evident in the better educated in these islands and elsewhere in the West.
In Britain the mortality in men of 60 years is three times greater in the less-educated social class 3 than in the professional and third-level education social class 1. I expect the same disparity exists in Ireland. Should we not put greater emphasis on education in Ireland rather than aspiring to a perfect health service to deal with elective illnesses?
Prof Risteárd Mulcahy is professor of preventive cardiology (emeritus) at St Vincent's University Hospital and UCD, currently head of the exercise stress testing facility in the Charlemont Clinic
Muiris Houston is on leave.