Are we predisposed to age at a certain rate?
How and why we age has long fascinated scientists, and there have been countless studies carried out on everything from worms to humans in order to try and better understand what causes our bodies to deteriorate over time.
In fact, so much research has been carried out in this area that findings suggests small variations in our genetic code can have a huge impact on how long we live and how well we age.
In a study published in Nature Communications in 2015, scientists identified almost 1,500 genes connected to the aging process by pooling information from 12 studies involving 14,983 people. The study analysed blood samples and observed changes in gene activity throughout the aging process on people ranging in age from 40 to 70.
Of the almost 1,500 genes uncovered in the research, many were the usual suspects long been known to contribute to the aging process, but some were uncovered that had not been thought to play a part – most notably, genes associated with compounds called glycosaminoglycans.
Essentially, glycosaminoglycans affect how well our body heals. It also contributes to healthy joint and nerve development. The latest research suggests that these compounds appear to decline with age, meaning that by maintaining the proper amount and type in our bloodstream, we could help to protect against the aging process.
This was just one of the more interesting findings of this one study, but to get to the heart of the question – are we predisposed to age at a certain rate? – we first need to explore what exactly is happening in our bodies. Here we take a look at three key factors of the aging process:
How do we measure aging? Using your chronological (legal) age as the measure may not always be accurate, because we all age at different rates. This means that your biological age could differ wildly from your actual age, in what is known as 'internal aging'.
Researchers from a number of institutions, including King’s College London and Duke University in the US, looked into this subject by studying over 1,000 individuals. What they found was that some in the study showed to be aging internally at a rate of three years for every one chronological year, while others seemed to be barely aging at all over the period measured.
Some 18 indicators of health were measured – including kidney and liver function, blood sugar, cholesterol levels and blood pressure – at three intervals between the ages of 26 and 38. The study found that while some in the group of 38-year-olds had a biological age closer to 30, others were closer to 60 (yikes!). And as is to be expected, those with biological ages higher than their actual ages showed the most outer signs of aging.
Genetic mutations and “turning off” the aging process
While mutation may sound like a bad thing, this process – which alters our DNA sequence – is in fact a very natural one. Essentially, when our cells divide and replenish, they quite often do not “copy exactly”, resulting in a slightly different cell than before. This is actually thought to occur around 120,000 times each time one of our cells divides! And the ultimate result is a mutation in the DNA sequence which is commonly associated with the classic signs of aging, such as hair loss and osteoporosis.
The mutation most commonly thought to be responsible for the aging process is the one which occurs in our mitochondrial DNA. Mitochondrial DNA is found within small organelles within our cells, and their role in the body is to create energy through cell respiration. Traditionally, the theory held that damage or “wear and tear” to mitochondrial DNA led to mutations in the DNA sequence which resulted in signs of aging. However, new research conducted by the University of Tsukuba in Japan suggests that another process may well be at work within our cells.
The Tsukuba researchers found evidence to suggest that, in actual fact, certain genes within the body are turned on or off over time. This discovery was made by comparing the function level of mitochondria in fibroblast cell lines from children under 12 to those of adults aged between 80 and 97. The scientists found that while the older cells had reduced cellular respiration, there were no more signs of DNA damage in these older ones than in the younger cells.
This is thought to be due to what’s known as epigenetic regulation – changes in the physical structure of the DNA which do not affect the DNA sequence but instead cause certain genes to be turned on and off. What’s most remarkable about this latest finding is that it raises the possibility that, with no damage present, epigenetic changes could potentially be reversed by reprogramming cells back to their embryonic state – halting, if not undoing, the aging process. Our environment and lifestyle is the key player in epigenetics, so let’s be clear that your genome is not destiny. Recent research also shows that your microbiome is also key to the aging process.
While mutations in our DNA have long been thought to play a part in the aging process, what is interesting is that the rate at which we age is not only influenced by the mutations which occur through our lifetime, but also by those mutations that are passed down to us from our parents.
When the cell and egg unite at inception, the fertilised egg receives DNA from both parents. If either strain of DNA has a mutation, that offspring will inherit it and carry it throughout its life in almost every cell of the body. It is thought that a woman typically passes on around 14 of these mutations, while a man can pass down as many as 80 by the time he reaches 40.
Research carried out in Germany and Sweden and published in the journal Nature recently found that some of these genetic mutations – particularly those found in the mitochondria, which is passed on by the mother – can have a huge impact on the way and rate at which we age. According to Professor Nils-Goran Larsson of Sweden’s Karolinska Institutet, "…our mother’s mitochondrial DNA appears to influence our own aging process… if we inherit mutations from our mother, we age more quickly."
Defective mitochondrial DNA has long been implicated in a litany of age-related diseases, from diabetes and heart conditions to dementia – often thought to be as a result of damage that occurs in our own lifetime. However, it now seems to be the case that when that naturally occurring damage is combined with inherited mutations, the end result can be a faster aging process.
For most of us, it’s almost entirely in our hands
In extreme cases you can witness something fascinating. I know a woman – aged 45 – who doesn’t look a day over 30. Despite being a smoker and a regular casual drinker and not one to go to the gym, she has flawless skin, and a face in particular that simply seems to defy the aging process. A look at her mother, who is 23 years older, reveals more of the same. And again, it truly is fascinating to observe.
In these extreme cases, what we are witnessing is something very different than someone who is simply “aging well” because he or she is living right by eating a good Paleo-type diet, avoiding toxins such as smoking or alcohol, and staying reasonably fit through a healthy dose of exercise. These “anti agers”, such as the woman and her mother I am referring to, literally look far younger than their years, whereas those “graceful agers” still look their years – but they just look great for their age.
But extreme cases aside – and these truly are rare cases – let me just make one thing very clear: While I wanted to present the more scientific side of the aging process in this article, what I’ve always believed is that despite your genetic makeup, it’s your lifestyle choices that play the absolute dominant role in how you look on the inside and the outside. And the latter usually influences the former very directly and significantly, meaning staying healthy is essential to looking good.
A great example of this are those famous personalities who have gone teetotal. Google something along the lines of “famous people who don’t drink”, and as you go through the results you’ll likely say to yourself, “Ah, of course”, as you realise that those celebs in particular who look very good for their age (or simply just look very healthy) are often those that don’t drink at all.
In the medical world there is a saying: “Genes load the gun, but lifestyle pulls the trigger.” which essentially means that regardless of what genetic lot you’ve been handed, it plays a much smaller role than you think. How you age; how you get sick and at what age you are going to die, your lifestyle is responsible for 90 percent of that, so make sure you’ve got a healthy one.
The opinions in the column are by Dr Graham Simpson, the Chief Medical Officer and Founder of Intelligent Health, a preventive medical centre located in Jumeirah, Dubai, and are not necessarily those held by Esquire or Hearst International.