Medical Matters with Dr Kevin McCarroll
Are we only as old as we feel? Is the new 60 actually 50? In an era of increasing longevity, one might think this is a deception designed to sooth the soul from the reality of ageing. However, not only are we living longer, we are postponing until later in life major ill health and functional decline, and maintaining a better quality and more active lifestyle.
As a geriatrician, I must admit I am terribly bad at estimating how old my patients are, which is reflective of the significant differences in physical health and function in later life in those of similar age.
There are of course multiple factors that contribute to this diversity that range from genetic to lifestyle to social and indeed simply good fortune.
The concept of ‘successful ageing’ has entered the medical lexicon in recent years and embraces optimising one’s physical, cognitive and mental health, and also social engagement as we grow older. All are interdependent on each other and can’t be taken in isolation. Indeed, it is by taking this multi-pronged approach to ageing and adapting positively to the changes in later life that is key.
The ‘oldest old’ represent the most rapidly expanding group in our population and indeed nearly 200 people can make claim to becoming centenarians every year in Ireland. As we know, the increase in life expectancy in the last century can be accounted for by reduced infant and perinatal mortality, use of antibiotics and vaccinations, better public hygiene and nutrition, improved medical care and reduced death in human warfare.
In the past, it was often the self-selected few who reached a ripe old age, by escaping ill health until very late in life and largely without the benefits of modern medicine. Today, the picture is different, for whilst more and more are living longer, those at extremes of age vary from the feisty well to the frail with multiple ailments who previously may have succumbed to ill health were it not for medical advances.
The genetic contribution to average life expectancy is approximately 25-30% but is probably significantly higher for those who live to extremes of age. Despite several studies including those of centenarians, there is little genetic understanding of longevity, though clearly it is apparent that some are more susceptible to the effect of environmental and lifestyle factors on disease, including smoking and alcohol.
Epigenetics may explain part of the differential effect of these factors, which may turn on and off genes variably in different people with subsequent negative effects.
Control of vascular risk factors is one of the most important preventative interventions of modern medicine as cardiovascular disease accounts for about 35% of all mortality. It can delay or prevent heart, kidney, peripheral arterial and cerebrovascular disease which otherwise can impact negatively on breathing, exercise tolerance, gait, cognition, mood and even risk of dementia.
Similarly, cancer mortality has dropped due to screening, better surgical treatments and chemo-radiotherapy options, but still accounts for 25% of all deaths. Avoidance of smoking, alcohol excess, obesity and a healthy diet will reduce the risk of several types of cancer. However, age of itself is one of the biggest risk factors and some may simply escape cancer on the back of good fortune.
Such is the ageing demographic, that there is now the emergence of geriatric sub-speciality interests in surgery, oncology and cardiology given the complexity of older adults.
There is no doubt that ill health and the effect of several diseases have been postponed until much later in life. What comes with this is also the challenge of the inevitable normal age-related decline in function and the increased incidence of other conditions like dementia.
It prompts the often asked question of how long we can expect to live and what is the maximum achievable age of human life. At present, about 5% of all centenarians reach the age of 105 or more, yet represent a group that has increased exponentially. Despite this, the number of those living to 110 or more has remained relatively static. To put things in perspective, it is also estimated that between 30-50 % of all females born today will live to 100.
The promise of stem cell technology and the development of specific molecular targeted therapies for cancer, Alzheimer’s and other diseases could radically change the landscape. Perhaps, our expectations should be higher.
After all, Jeanne Calmette (the oldest person to have ever lived) became an ultra-centenarian and only met her demise at 122 years of age!
For now, I can only extoll the benefits of maintaining a physically and mentally active life, keeping socially engaged, paying attention to having a healthy diet, monitoring for vascular risks factors and checking in with your GP not too infrequently!
Dr Kevin McCarroll is a consultant physician in geriatric medicine in St James’s Hospital, Dublin.