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Age Proof — The New Science of Living a Longer and Healthier Life - extracts from Professor Kenny's new book

A new "groundbreaking" book on ageing featuring findings from "cutting-edge" research from Professor Rose Anne Kenny's extensive career in the field of ageing will reveal why and how some people live longer, fitter, healthier and happier lives than others. Read an extract from the book below.

Read the Times UK article here.

Some of us appear resilient to ageing while others seem older than our years, notes Professor Rose Anne Kenny, award-winning geriatrician and researcher, and Head of medical Gerontology at Trinity College Dublin, in her new book Age Proof - The New Science of Living a Longer and Healthier Life. No two 83-year olds are the same. One can run a marathon and the other is a frail nursing home resident. But why? Because our biological changes count more than the crowd of candles on our birthday cake.

One study showed a difference of 20 years in biological ageing clocks in adults as young as 38. The good news is that it’s within our power to modify and improve most of the factors that influence our clocks. We control 80 percent of our ageing biology, says Professor Kenny. (Banning ageist language and attitudes is a good start.)

Kenny, whose sub speciality is cardiovascular medicine, is also founder and Principal Investigator of the Irish Longitudinal Study on Ageing (TILDA) - which has followed almost 9,000 adults aged fifty and older, and generated over 400 research papers. The study covers all aspects of life - from sex to food, to physical and brain health, genetics, childhood experience, expectations, friendships, finance and much more - to illustrate why and how we age.

Most of us are eager to know more about ageing and health. Yet at the same time many people in midlife tell her they can hardly bear to think about growing old, such is their dread of it. But, she writes, the “last lap” - as one of her patients cheerily calls it - can be the most relaxed, worthwhile and contented period of our lives, especially if we prepare for it. So if you’d like to enjoy a longer, happier, healthier existence, here is the expert’s advice, after 35 years at the forefront of ageing medicine.

Your attitude keeps you young (or not)

It turns out that the inspirational Instagram quote “Age is not a number” is based on science. Our work and other research confirms that we are indeed as young as we feel. One of our studies showed that people who feel their chronological age are more likely to develop physical frailty and poor brain health than those who claim to feel younger than they are. Older adults with negative perceptions about ageing are likely to die seven and a half years earlier, mostly because of higher rates of heart disease.

Meanwhile, feeling younger than our years - irrespective of whatever diseases or disorders we might have - slows the pace of ageing. How? Because a positive attitude towards getting older changes cell chemicals beneficially, possibly by reducing inflammation (low-grade chronic inflammation, from impaired immune responses, is associated with accelerated ageing and many age-related conditions). Even if we have health problems, attitude dominates.

A unique piece of research - the Nun Study - perfectly illustrates this. The 678 sisters of School Sisters of Notre Dame in the US took part in a longitudinal study, undergoing regular health and psychological tests, plus a post-mortem brain pathology study. (A great advantage was that they lived similar lifestyles.) Broadly, it was found that the nuns who expressed more positive emotions lived on average a decade longer than their less optimistic peers, and were less likely to get dementia. Aged 80, sixty percent of the least happy nuns had died.

But society’s attitudes matter too. Ageism - being forced to retire rather than choosing for oneself for instance - is pernicious and detrimental. A Yale University study showed how perceptions about ageing can change our physiology. Exposure to positive ideas about ageing - eg. words like ‘sage’ - helped participants deal with stress. A barrage of negative stereotypes - eg ‘senile’ - increased stress, prompting higher blood pressure and heart rate. Don’t stand for ageism - it has directly damaging effects on health.

Find your purpose

Having purpose is a psychological strength, key to a contented, longer life. Yet sometimes as we age, we lose sight of this. Families dissipate, we retire, our social life shrinks. So how do we find meaning, even in the most challenging of situations?

Proven effective is nurturing our creativity. I am director of the newly established Mercer’s Institute for Successful Ageing, at St James’s hospital in Dublin. This clinical and research facility includes a central hub for patients and staff to be creative - through poetry, song, painting and music. Neurological research shows that making art improves not just mood but cognitive function by forming thicker and stronger new connections between brain cells. At the very least, you might visit a gallery - even viewing art has a positive effect.

We can also rediscover purpose by taking on new challenges. Abundant data shows that people who volunteer are less depressed and enjoy better quality of life. For some, religion provides meaning. Overall, religious involvement, belief and spirituality are linked to lower depression and anxiety, better memory, better planning and organising abilities, and longer life - though the social factor may be significant in this too.


Good friends add years to our lives. Examining the association between social bonds and health, I was staggered by the powerful physical effects of friendship. But why would the strength of our social contacts and social engagement affect mortality? It’s been suggested that they lower levels of stress and stress-related hormones, heart disease and inflammation.

Supporting this explanation, Harvard researchers recently found that greater friendship and familial bonds independently predict lower concentrations of fibrinogen, a clotting factor in blood, a cause of blood clots and heart attacks, and an indicator of inflammation. The association between fibrinogen and social isolation, conversely, was remarkable - it was as bad as smoking. (Important note: if relationships are strained - whether family, partner, or friend - chronic disease was more likely.)

Brain health

Another Harvard study found that people who enjoyed strong social bonds into their eighties were less likely to succumb to cognitive decline and dementia. The fact that social, mental and physical stimulation through friendships reduce vascular diseases is relevant here too. High blood pressure, high cholesterol, heart irregularities such as atrial fibrillation in midlife, are all associated with Alzheimer’s in later life. The stress-busting effects of good friendships is another reason these relationships benefit brain health. A higher susceptibility to stress doubles the risk of dementia by triggering chronically high cortisol levels.

A third theory as to why friendships are brain-protective is that mental stimulation provided by social contacts increases the formation of new brain cells, building up capacity or “cognitive reserve” in the area that converts short term memory to long-term memory, the area important for concentration, understanding, awareness, thought, language, and consciousness, and the area governing our sense of smell. So even if people have abnormal proteins in their brain cells (dementia pathology) they don’t show signs of the disease - their reserve capacity enables normal function.


We laugh more when we’re with friends - laughter bonds us with others. As well as boosting endorphin levels, laughter is a form of muscular exercise, good for circulation and digestion. Fundamentally, it’s a different way of breathing. We’re using the muscles between our ribs to repeatedly blow air out from the lungs without inhaling. It increases the pressure in the chest by effectively breath-holding and stopping the normal rhythmic flow of air in and out. A good belly laugh provides a workout for the diaphragm, abs, and shoulders - plus the immune system and heart. It’s beneficial at a chemical level because it lowers the stress hormones cortisol and adrenaline. And low cortisol stabilises blood sugars and insulin, regulates blood pressure, and reduces inflammation. (NB. Even if we anticipate having a laugh, our positive hormonal system kicks in - rising as much as 87 percent. The same expectation muted stress hormones by up to 70 percent. Time to revisit Seinfeld or Father Ted?).

>Why stress is ageing - how we react is key - 7 protective tactics

We all know how stress feels to us - but its medical definition is “the quality of experience, produced through a person-environment transaction that, through either over arousal or under arousal, results in psychological or physiological distress.” Stress has many biological measures - it affects our nervous system, hormones, immune system and metabolic systems. Persistent stress can lead to obesity, diabetes, high blood pressure, a fast heart rate, heart attacks and strokes. A visible measure of how acute stress can age us is that it can turn hair grey.

Harvard researchers found that stress activates the sympathetic nerves - part of the flight or fight response. Examining the impact of stress on the hair follicle, they found that these nerves, which feed the follicles, release the chemical noradrenaline. The intensity of its release depletes hair pigment - as well as accelerating hair loss. Greying, they concluded, is indicative of the biological effects of stress. (The silver lining - their research lays the groundwork for discovering how stress impacts other tissues and organs - a step towards eventual treatment to halt its adverse impact.) Meantime, these techniques can provide a buffer against stress:

  • Acclimatise to regular periods of switching off - for instance, a time each day when phone and internet are out of bounds. Develop routines to de-stress so that it doesn’t become chronic.
  • Confess your worries to a friend. University of Southern California researchers tested the saying “a problem shared is a problem halved” - they found it does indeed reduce stress, lowering cortisol.
  • Take up gardening. A recent paper analysed 22 studies on gardening and health - its host of positive effects include reductions in depression, anxiety, and BMI, plus a rise in life satisfaction, and quality of life.
  • No garden or window box? Go for a walk. In nature, preferably - forests have a notably calming effect. But our body loves motion and walking per se is beneficial. Our mood improves, stress levels fall, creativity increases dramatically. Even walking indoors on a treadmill facing a blank wall (as opposed to sitting down) enhances creativity.
  • Eat meals with others when possible. If sitting down with family or friends just once a week is achievable, make it an honoured routine. Keep the food simple so it doesn’t become a chore, share responsibility, and plan it.
  • Proven techniques to lower stress include controlled breathing, meditation, and dispositional mindfulness - take your pick. Brain scans show that meditation preserves the brain’s main structural tissues. It also potentially suppresses processes that contribute to brain ageing. Dispositional mindfulness meanwhile - a keen attention to present thoughts and feelings - has physical, psychological, and cognitive benefits (it’s the opposite of letting our mind wander, fretting about the future.)
  • You’ve heard this before but - consider yoga. As well as improving balance and flexibility, at a cellular level, it reduces inflammation and thereby slows biological ageing. Several studies show that yoga increases the length of telomeres - the protective coverings at the end of chromosomes which stop chromosomal damage. (With ageing, telomeres shorten, chromosomes are damaged, cells decay and die.)

The good stress - exercise - your ultimate anti-ageing strategy

In the 1950s, two London pathologists observed that they were performing more post-mortems after sudden death on bus drivers than bus conductors. They also realised that more desk-based post office workers than postmen were dying in middle age from heart attacks. This was the first inkling that sedentary occupations were associated with early death - and was confirmed by subsequent study of the post-mortem details and occupational history of 5,000 men.

So let’s remind ourselves why, say, trotting up and down the stairs of a double decker all day, is so good for the heart. It improves circulation, reducing the risk of clotting in arteries. It keeps the heart muscle strong. A strong heart lowers your heart rate, because fewer beats are required to pump the same amount of blood around the body. This reduces pressure on the heart - and so the force on the arteries decreases, lowering blood pressure. Good cholesterol, which lowers the risk of thickening of arteries, increases too.

Exercise is great for mental health and brain health as well. As you break into a sprint, or pace up that hill, the brain recognises the start of activity as a moment of stress, as if you are either fighting the enemy or running from it. It releases a protein called BDNF (brain derived neurotrophic factor), protective against stress. This supports the growth of new nerve cells which enhance brain function, brain health, and cognitive performance.

Furthermore, exercise increases the size of the hippocampus, area of learning and memory in the brain. (This normally shrinks in late adulthood, leading to impaired memory and ultimately increased dementia risk.) Physical activity slows the shrinkage, and aerobic exercise, even in older adults, has been shown to increase its size and improve memory. It can even reverse the hippocampus’ age-related shrinkage by up to two years. The emerging consensus is that exercise in midlife prevents or delays dementia in later life - some studies suggest it lowers the risk by 30 per cent.

We know that low or no generalised inflammation in the body slows ageing, whereas higher inflammation accelerates it. Exercise lowers our background inflammatory state, and so leads to a reduction in conditions, more common as we age and linked to chronic low-grade inflammation, such as arthritis, cancer, diabetes and strokes. The fat that settles on our bellies (and around our internal organs) is particularly bad news as these fat cells produce toxic proteins which trigger inflammation. Exercise however, releases enzymes called myokines that transiently block harmful inflammatory proteins, and promote the release of anti-inflammatory proteins.

Fitness for anti-ageing - what you need to do

• Walking or running 20K per day is the modern equivalent of a hunter-gatherer’s exertions (with frequent squatting rather than sitting). But don’t be disheartened - just 150 minutes of walking a week is protective against depression. And more vigorous exercise, such as cycling, swimming, has even more powerful benefits.

• If you are sitting for prolonged periods, stand up every 45 minutes - it’s good for improving blood flow to the brain.

• Exercise - especially running - elevates a protein called Cathepsin B, which enhances brain function. It’s secreted by muscle cells and promotes and accelerates growth of new nerves.

• Resistance exercise mitigates the effects of ageing on nerves that feed skeletal muscles. At cellular level, oxidative stress is improved and mitochondria function more efficiently. Work towards two to three sets of one or two multi-joint exercises per major muscle group, two or three times weekly. It’s rarely too late - studies show strength benefits in people over 90.

• Don’t rule out protein supplements. A recent trial of 360 adults with age-related muscle loss, low muscle power and mass gained in strength and muscle mass after supplementing daily with leucine whey protein and vitamin D for three months. I have a protein whey drink after every resistance training session.

Try to love cold water

Swimming in a chilly lake, sea, or lido, or having a cold shower (15-23 degrees C) is a physiological stress. In small doses, this kind of stressor is good for us. Cold water in particular benefits a range of systems involved in the ageing process. Noradrenaline, a critical neurotransmitter and part of our flight or fight response, rises fourfold on cold water exposure - and it’s released in brain areas that control emotions, concentration and memory.

As our responsiveness to noradrenaline declines with age, anything that enhances its activity is important to ageing physiology. Indeed, one of my neuropsychology colleagues at Trinity College Dublin suggests that such stimuli may prevent dementia. Cold water exposure also releases endorphins, and improves immunity. (One study found taking routine cold showers led to a 54% reduction in sick leave. Bonus: the duration of the shower didn’t seem to make a difference.) It also increases our calorie burn at rest, and improves circulation. And the British Medical Journal has reported on how cold water swimming can alleviate depression.

If the very thought of this leaves you cold, you might consider instead a trip to the seaside. Our research has shown that merely gazing at the sea has a positive benefit on mood and wellbeing. And living close to the coast is linked to better mood, less depression, less anxiety and greater wellbeing. It can add four to seven years to lifespan. Pack your bucket and spade… and swimsuit?

Age Proof — The New Science of Living a Longer and Healthier Life will be published Lagom imprint on 27th January 2022, learn more here.