Why midlife is the perfect time to take control of your future health

It is fortunate that the enemy is unable to correctly determine the intent of GOD.

Yet this is how the other side was able to tell me that i would see my 100 th birthday.  And plausibly my 300 th birthday as well because of our advancing  science.  just saying.

and because i know this, if it does not work out that way, just who is going to care?

So yes, the take home today is to live your life as if you will reach 100. do those healthy things.  You will walk on stage it you do, just like George Burns and Bob hope.

Why midlife is the perfect time to take control of your future health

The lifestyle choices you make in middle age play a particularly important role in how your brain ages

By David Robson

17 July 2024

https://www.newscientist.com/article/mg26335000-100-why-midlife-is-the-perfect-time-to-take-control-of-your-future-health/

Next year, I will be celebrating the big 4-0. It seems a little absurd. I feel barely any older than I did when I enjoyed my 20th birthday. I have hardly recovered from the ups and downs of adolescence, and now I am apparently staring down the barrel of midlife.

I have tried denial, but there is no escaping the truth. It is generally accepted that middle age begins at 40 and ends in our early 60s. And while the most visible signs might be the crinkled skin around my eyes and mouth, the latest research suggests that my brain will also undergo a series of important changes in this period. They include the accelerating shrinkage of certain brain regions, loss of connectivity across the brain and damage to neurons owing to inflammation – all of which appear to contribute to later cognitive decline.

You might think this would heighten my existential anxiety. But there is room for optimism, because it has also become clear that midlife offers a vital window of opportunity to preserve our brain’s health.

The upshot is that by making specific lifestyle changes in your 40s and beyond – some of which go beyond the obvious – you can reap immediate benefits to your memory and concentration. What’s more, with some persistence, you can boost your chances of maintaining a sharp and sprightly mind well into old age, while significantly reducing your risk of dementia. “It really isn’t too late to make a difference,” says Sebastian Dohm-Hansen at University College Cork in Ireland.

It is only within the past few years that researchers have started to take a meaningful interest in the transition between young adulthood and later life. “Middle age has been sort of sidelined a bit by the scientific community,” says Dohm-Hansen, who recently co-authored a paper that summarises the state-of-the-art research on the middle-aged brain.

The lack of interest was partly the product of practical challenges: if you want to understand a phenomenon like cognitive decline, it is far easier to detect the differences between people when the symptoms are already well-established. “You are going to see the clearest signals when measuring people who have 70 years of cumulative risk,” says Maxwell Elliott, a neuroscientist at Harvard University.

By this age, however, many of the changes may be irreversible, prompting researchers like Elliott and Dohm-Hansen to take a closer look at earlier life stages. “What you want to study is a period of life where there’s a lot of accelerating change, and that also presents an opportunity for intervention,” says Dohm-Hansen. “Increasingly, the field is starting to appreciate that this may be middle age.”

What happens at middle age?

Their research requires us to rethink a key assumption about ageing. In the past, it seemed natural to see age-related decline as a linear process. According to this model, most of our cognitive abilities reach their peak in our 20s and 30s, then steadily fall with time, so that the rate of change would be the same in our 50s as it was in our 20s.

When scientists tracked people’s brains over time, however, they found that many of the alterations happen in fits and starts – and middle age seems to mark a turning point.

Consider episodic memory, our capacity to remember the details of individual life events, which starts to decline increasingly rapidly over middle age. Of particular interest is an ability known as pattern separation, which prevents similar recollections from becoming confused. If you need to remember where you parked your car, for instance, you have to be able to differentiate today’s memory of driving into the car park from yesterday’s. For many people, that task becomes far more challenging as they enter their 50s and 60s.

Fitness in middle age seems to make a particular difference to dementia risk

Richard Gray

Such memory problems can be traced to changes in a brain region known as the hippocampus, which tends to slim down more rapidly in middle age, according to Dohm-Hansen. This area is known to be involved in the encoding of new information. According to one hypothesis, the brain starts to lose its ability to form new neurons during midlife, which makes it harder to build the distinct neural networks needed to differentiate the details of one memory from another.

Age-related scattiness may also come from changes to the brain’s connectivity, both structural and functional. The structural changes include the thinning of the brain’s white matter, long-distance axons coated in an insulting sheaf that carry signals from one region to another. “Some of these actually appear to peak in your early 40s, after which there is an ever-faster decrease in volume,” says Dohm-Hansen.

The functional connectivity concerns the ways that the brain organises its processing – which regions work together at which time. In younger adulthood, the processing appears to be more modular: we have very distinct networks that work on specific jobs. In much the same way that a clear partition of responsibilities can enhance the performance of a sports team, this is thought to improve efficiency. Once again, in middle age, we start to see significant changes occurring. At this time, the brain’s tight organisation starts to loosen up, with less segregation of the different networks. The magnitude of that change is strongly associated with your overall cognitive abilities and memory of everyday events, says Dohm-Hansen.

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Like other forms of ageing, we each face an individual trajectory that may be markedly different from another person’s. Some of this variation may be hardwired in our DNA. People who carry a particular version of the apolipoprotein E (APOE) gene are considerably more likely to develop Alzheimer’s disease, for example. Research by Teal Eich at the University of Southern California and her colleagues shows that the effects of this gene are invisible until middle age, after which the consequences for episodic memory become increasingly pronounced.

Our genes don’t seal our fates, however, with emerging evidence showing that the brain’s path through middle age is intimately linked to our overall health – which can be modified by lifestyle factors.

This tight coupling between body and mind was evident in one of Elliott’s studies, published in 2021. Working with a global team of scientists, he examined the records of 1037 people born in Dunedin, New Zealand, between April 1972 and March 1973. The researchers chose 19 separate “biomarkers” that each indicate different elements of health as we get older, such as body mass index (BMI), hip-to-waist ratio, cholesterol, lung function, blood pressure, tooth decay and levels of an inflammatory molecule called C-reactive protein. “We wanted to measure ageing of the entire biological system,” says Elliott.

Pace of Aging

From these individual measurements, the researchers could calculate a single score representing the wear and tear on the participants’ organs – what they called a Pace of Aging (POA) score. These differed substantially from person to person, and they generally reflected outward signs of ageing. An individual’s POA seemed to correspond with other subjective judgements of their physical appearance, for example: the higher the score, the older they looked for their age.

Could the POA scores also reflect the speed of people’s neural decline? To find out, Elliott’s team examined brain scans and tests of cognitive performance. The results revealed a tight link between the body and the brain, particularly in middle age. At around 45, participants with higher POA scores showed faster deterioration of the hippocampus and greater loss of white matter, for instance. They also showed a larger drop in general intelligence. “People who are ageing faster, on average, lost a few IQ points,” says Elliott. “They were already losing a little bit of cognitive ability that might set the stage for things like dementia in old age.”

The precise mechanisms are still under investigation, but there are lots of potential routes through which these bodily biomarkers could influence the brain’s health. Obesity, high blood pressure and high cholesterol, for example, individually and collectively increase the chance that the brain’s blood vessels become blocked or damaged, causing fluid to leak into the surrounding tissue, where it can harm neurons and their white matter – irreversible damage that begins in middle age.

Irreversible damage to brain cells can begin in middle age

JUAN GAERTNER/SCIENCE PHOTO LIBRARY/Alamy

Then there is inflammation. This is one of our body’s vital weapons against infection, but only when it is used sparingly. Unfortunately, the immune system can sometimes go awry, pumping out inflammatory molecules when there is no immediate threat. Over time, this wreaks havoc in the brain, killing its cells and breaking their links, and it is thought to contribute to the build-up of protein plaques in Alzheimer’s. “There’s evidence that some of these inflammatory processes accelerate during the midlife period,” says Dohm-Hansen.

The upshot is clear: if I want to start cultivating healthy habits, I had better start now, before the damage begins to accumulate. “From everything we know about the brain, it seems it’s pretty hard to get back something that has been lost,” says Elliott. “But you can prevent things from getting lost in the first place.” And middle age may be an especially important time to take action, regardless of the lifestyle choices you have made previously.

Healthy habits

That was the conclusion of the Lancet Commission on Dementia Prevalence, Intervention and Care, which examined the impact of various risk factors across the lifespan. It found that a few take on particular importance in middle age. For instance, while it is always advisable to manage our weight and control our alcohol consumption, the commission concluded that these behaviours have a particularly significant effect on our later dementia risk once we have reached our 40s. In other words, middle age is the prime time to cut down on the beers and burgers if we wish to preserve our minds later in life.

We might also get our ears tested. Following a conversation is a considerable mental workout and hearing loss can discourage us from engaging with others, depriving us of this cognitive exercise. “The easiest way to stimulate your brain is to just chat, and that makes your brain more resilient,” says Gill Livingston, a professor of psychiatry of older people at University College London, who led the Lancet commission.

Danilo Bzdok at McGill University, Canada, who has studied the effects of our relationships on our brain structure and function, has similar advice. “I would argue that the most complicated processes that most people’s brains compute on a daily basis is keeping track of and thinking about constantly changing social dynamics.” This may help explain why loneliness is associated with an increased risk of dementia – but it is by no means the only reason. Social isolation can be a potent form of stress that triggers inflammation, for instance, resulting in poorer overall health. Many people find their social circles dwindling in midlife, so this might be a prime time to look for ways of connecting with your community.

Middle age is the prime time to cut down on alcohol to preserve your mind in later life

Martin Parr/Magnum Photos

Last, but not least, we should watch our daily step count. It is now well known that exercise improves circulation and reduces inflammation in both the body and brain. It also triggers the release of brain-derived growth factor, a protein that helps maintain the health of our neurons and their links. As a consequence, maintaining a decent level of physical activity during middle and old age appears to slow the neural damage that typically accumulates with each passing year.

“Physical activity is very, very associated with a decreased risk of dementia in short and long-term follow-ups at all ages,” says Livingston. “But fitness at midlife seems to make a particular difference.”

This is good news for me. I have a BMI of 21 (in the “healthy” range) and – thanks to the flexibility of my working schedule – manage to walk or run more than 10 kilometres a day. I could try to increase that activity, but Dohm-Hansen warns that excessive exercise regimes may do more harm than good. “If you do too much of it, intense exercise can increase inflammation quite dramatically,” he says. Maintaining moderate exercise is more than enough – and far more achievable for most people.

Public health campaigns have already improved middle-aged health and fitness in many different countries and this may be why we are seeing a noticeable difference in people’s mental acuity. Although the total number of people getting dementia is rising with the increasing life expectancy of the world’s population, the relative proportion of people developing the condition within each age group is shrinking – a ray of light that is often obscured in the popular discourse.

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“This is associated with greater education, decreased cigarette smoking and decreased hypertension,” says Livingston. The benefits for younger generations are substantial, with one analysis of data from the US and Europe concluding that the risk of developing dementia is falling by 13 per cent with each decade that passes. Livingston hopes that more targeted interventions will continue to build on these improvements. “It looks like there’s an absolutely enormous possibility of decreasing dementia,” she says.

Speaking to these scientists has certainly left me feeling a little more sanguine about the big 4-0. This change in mindset may itself improve my prognosis. As New Scientist recently explored, various studies show that people with rosier views of ageing tend to enjoy better health and a reduced risk of dementia in the years ahead. It may be that the positive attitudes encourage us to remain more active and reduce the sense of vulnerability that might set in as we get older, so we feel less stressed, all of which should enhance our mental and physical well-being. Whatever the reason, I am trying to see my 40s, 50s and 60s as a time of immense opportunity.

“When talking about middle age and its relevance to cognitive decline and neurodegenerative disease, it does kind of sound a bit doom and gloom,” says Dohm-Hansen. “But it’s important to note that it’s part of the natural life course. The brain can start to leverage its compensatory mechanisms, and there’s plenty of room for intervention.”