Opinion: the major advances over the next century in the prevention of disease will come from integrating physics with other sciences
In the last 100 years, there have been incredible advances in science that have had profound effects on human health and longevity. During this time, global life expectancy has doubled to around 70 years with life expectancy at birth increasing at around four months every year. Using these projections, it is reasonable to conclude that life expectancy may be close to 100 years by the end of this century.
The rapid increase in longevity over such a short period of time is attributed to decreased child mortality, rising living standards, improved lifestyle, better education and advances in healthcare and medicine. Of these factors, the decrease in child mortality evident up to the 1950s and the increased survival of those older than 65 years in the second half of the 20th century are the most impactful.
The scientific advances in immunology and vaccine development have played a major part in reducing child mortality, while better healthcare and the pharmacological treatment of chronic disease in particular have played a major role in keeping people alive for longer. Many of the most important discoveries have been acknowledged by Nobel awards in physiology/medicine or chemistry. However, the development and introduction of new drugs is slowing and in some cases existing drugs are being successfully repurposed for other diseases.
What does the future hold?
One of the consequences of pharmacological treatment is that people are living longer with one or more chronic disease and the overall cost of delivering healthcare is becoming more expensive. The major advances over the next century will be in the prevention of disease leading to a greater number of healthy life years. There will still be major contributions from research in physiology, medicine, biology and chemistry, but the greatest advances will be made by integrating physics with these other disciplines.
This is not to suggest that physics has had no role in healthcare or biology to date. Quite the opposite, in fact. Without advances in physics, we would not have imaging technology, including CT, MRI and PET scanners, that provide valuable information to clinicians on the diagnosis and monitoring of disease. In a very different field, the Nobel prize winning physicist Erwin Schrödinger delivered a number of public lectures entitled What is Life? while working at Trinity College Dublin 75 years ago that have had a major impact on molecular biology to this day (a celebration to mark this historic event will be hosted by TCD next month)
The potential for disease prevention lies in the need for more detailed information on the early, subtle changes that take place in the cells of our body and the development of new technologies to reverse or repair these changes as they happen rather than waiting until they progress to a disease state. The real trick is to see if we can do this without invasive procedures, tissue sampling or surgery. This is where physics will play such an important role.
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While MRI and CT scans have been extremely beneficial, the next wave of imaging technology will include the ability to capture 3-D images of cells deep within living systems. Technology being developed by physicists and engineers at CERN, the European Organization for Nuclear Research, to probe the fundamental structure of the universe, is being used to develop the first 3D colour X-ray of a human. These technologies will allow a more detailed examination of cells and how they function under normal conditions, but also be able to detect smaller changes at an earlier stage. Think what this could mean for the detection of cancer or early stage cardiovascular disease.
Early detection is just one component, but some action still has to be taken to stop or slow the further deterioration in cell function. The small subtle changes detected prior to the onset of disease are likely to be too small to meet the criteria for conventional pharmacological approaches. Given the sensitivity of these measures, it is also likely that a more targeted approach to disease prevention will be required. There is little point giving a drug that could act in many parts of the body when the early indication of disease is only evident in a small proportion of cells in the body.
Treating diseases by non-invasive technologies
Magnetic fields and ultrasound waves have played an important part in developing the imaging technology that we currently use and they may play a more important role in future treatments. In recent years, the FDA in the US has approved the use of transcranial magnetic stimulation for the treatment of depression. This procedure, featured on a recent Brainstorm article, targets specific areas of the brain with a magnetic pulse to alleviate depression and is mostly used when other treatments have not been effective.
It is also possible that ultrasound waves will play a role in disease prevention. The development of high intensity focused ultrasound has been touted as a treatment for prostate cancer and has also been linked with Parkinson’s disease and depression.
While not widely used at this time, these approaches provide evidence that non-invasive procedures can be used to target specific parts of the body to treat or, in the future, prevent certain diseases. If we have more sensitive imaging to detect early changes, coupled with non-invasive prevention strategies, the possibility of increasing the number of healthy-life years by a decade becomes a real possibility.
The applications are endless and can be applied to any area of health. For example, there was a recent paper showing that an increase in heat sensing in the hypothalamus (an area of the brain that controls energy balance, amongst others) of mice after exercise was responsible for appetite suppression. If we were able to use magnetic fields or ultrasound to non-invasively target the hypothalamus and increase heat detection, there might be a way to reduce appetite and prevent the onset of diseases related to weight accumulation.
These examples already exist and are at the early stages of development or utilisation. The major innovations in the next few decades are likely to emerge from advances in quantum mechanics and their application to biological processes. It is already thought that Quantum Biology plays a role in photosynthesis and our ability to smell, amongst others.
One of the more interesting discoveries has been the cryptochrome protein, a light receptor in the eye of some migratory birds which detects the earth’s magnetic field and helps with migration patterns. This evidence of an interaction between biological processes and magnetic fields is just one example of the overall potential that exists if we can better understand the fundamental processes that underpin their regulation. With this, we will be better placed to develop novel technologies and applications to enhance health and longevity.
Scientists are always looking to develop new knowledge that can be used for innovation and future application. The further integration of physics with biology, chemistry and physiology has the potential to create enormous opportunities over the next few decades. One of the most important will be to help us stay healthy and independent for longer.
The views expressed here are those of the author and do not represent or reflect the views of RTÉ