How old are you really?
Posted on 26 October 2017
You may have noticed that people who exercise often, get plenty of sleep, and don’t smoke or drink generally look better, live longer and seem to have plenty of energy. Here’s some of the science behind this.
Physical decline associated with growing old is caused by biological process, influenced by both genetic and environmental factors.
We all age: it’s programmed into us and as we all know, it’s inevitable. However in the last few years, researchers agree that weight, eating habits, amount of exercise, cholesterol levels and alcohol consumption all contribute to how well we age. Research into ‘how old you really are’ (in other words, what shape your body is in versus how many candles are on your birthday cake) is ongoing.
How can we measure our biological age vs our chronological age?
‘More than 100 risk “calculators” have been developed in the scientific community, and by various interest groups and commercial companies,’ says Professor Vicki Lambert, head of the Division of Exercise Science and Sports Medicine in the Faculty of Health Sciences, University of Cape Town, based at the Sports Science Institute of South Africa. ‘The scientifically developed risk calculators typically are based on observational studies in large groups of people followed over long periods of time, and estimate the risk of developing a disease or dying based on one or more specific exposures.’ Some of these risks are modifiable (smoking, exercise, certain dietary habits, overweight or obesity, stress) and some are non-modifiable (age, gender, family history of disease).
Some of these calculators are:
The GlycanAge test claims to be the most accurate method to determine biological age. This test focuses on the structure of a protein found in blood serum that’s involved in the immune response and is modified by the addition of glycans – sugar molecules that decorate the surface of proteins and influence the way they function.
The MARK-AGE Consortium uses a battery of tests covering multiple aspects of ageing, including classic tests (such as body mass index, blood pressure and lung function) and new ones (testosterone levels, inflammatory markers).
A ‘brain age’ test combines MRI scans with machine learning algorithms to measure the difference between a person’s brain age and their actual age.
Another way to estimate biological age comes from investigating DNA methylation patterns (DNA methylation is a tool that cells use to lock genes in the ‘off’ position).
What is the most significant differentiator, in terms of lifestyle choice, that creates the biggest gap between ‘real’ age and chronological age?
‘For me, physical inactivity is usually the most prevalent or common risk factor,’ says Lambert. She points out that 30 minutes of moderate to vigorous activity on all or most days of the week is the least expensive and often the easiest risk factor to address. ‘It generally has favourable impacts on other risk factors, such as blood pressure, blood sugar levels, being overweight and stress,’ she says.
How can we slow the process of ageing?
There are four main areas to focus on, advises biochemist Professor Brian Kennedy of the National University of Singapore. These are: a healthy diet (plenty of fruits and vegetables, very little animal protein and processed foods, and relatively low dairy levels), exercise (cardiovascular and resistance training), enough good-quality sleep and careful management of stress.