AS a doctor who combines his day job as a (semi-retired) consultant physician in occupational medicine with the leisure activity of being medical adviser to a professional football club, I paid considerable attention to your report on the possible links between heading footballs and the development of dementia ("Doubts raised over theory heading ball raises players' dementia risk", The Herald, March 13).

It is reported that Dr Alan Carson, a widely respected neuropsychiatrist, stated that that the risks of players developing dementia are probably misplaced, since one in five people over 75 have dementia, and most have never headed a ball in their lives. He may be right, but while the fact is correct, I wonder if the conclusion he draws from it is flawed.

If one draws a parallel with my own specialty, depending on how they are defined and counted, the health problems traditionally closely associated with occupation – the poisonings, lung diseases, tendon disorders, infections and so on are reported very rarely these days although they may well be under-reported. While these low numbers may seem reassuring, it has to be remembered that they are often derived from a relatively small pool of employees, so while the absolute numbers are low, the risks to these workers are much higher than those experienced by the general public.

The question that really needs to be answered is "Is Billy McNeill (and others) more likely to be among the one in five 75-year-olds suffering from dementia as a result of their occupation, or not?" Special attention needs to be paid to the Frank Kopels and Jeff Astles of this world, whose dementia was diagnosed before they reached retirement age, when the prevalence of dementia in that population is in the order of one in 100.

Hence the importance of a properly organised studies, which may have to be undertaken by more than one group of researchers. One might predict that footballers who spent lengthy careers with top clubs where, in addition to the normal run of league fixtures and training, lengthy runs in cup, European and international competitions were the norm would have higher rates of dementing-type illnesses than players who spent most, if not all of their careers in lower division clubs. For part-time players, with more limited time available for training, the risk might be lower still.

Whatever the outcome, at least the authorities might have a better grasp of the scale of the problem which might at least allow appropriate action to be taken to mitigate the problem if it exists, and prospective players may be better able to judge the risks of a career in football.

Christopher W Ide,

25 Riverside Road, Waterfoot, East Renfrewshire.