People tell me I look younger than I am. But as flattering as that is, my appearance isn’t that important to me. Well, not compared to my biological age, anyway.
Representing how well your body functions, your biological age gives a more accurate picture of your overall health and longevity potential – reflecting factors like genetics, lifestyle, and environment rather than just the years you’ve lived.
Fundamentally, your biological age represents how long you can live a healthier, happier life. You can measure it in a lab (by looking at how much your DNA has been altered by a chemical reaction called methylation) or at home (for example, by testing your hearing range or how long you can stand on one leg).
And, crucially, you can change it.
Ever since I lost my grandparents to Alzheimer’s and Parkinson’s, it’s an idea that’s driven me: could it be possible to slow my biological age?
Recently, I lost both my parents to the same terrible diseases. My children are still young, and it’s a huge regret for me that they didn’t get to know my parents.
Everyone should be able to experience their parents being part of their children’s lives – especially with them staying healthy into old age.
And this, I think, is the whole point: we want to be healthy for as long as possible. But simply knowing your biological age won’t do much for you – I wanted to know what I could do about it.
That’s why I conduct clinical trials in my lab, and why I decided to start testing my anti-ageing experiments on myself.
Think I sound mad? I’m by no means the first scientist to self-experiment. In fact – and make sure you’re not eating when you read this – in 1982, the bacterium that causes gastric ulcers was discovered because the Australian researcher Prof Barry Marshall took extracts of patients’ stomach ulcers and drank the fluid.
He gave himself an ulcer that he then cured via penicillin – and won a Nobel Prize for these efforts in 2005. (Luckily, anti-ageing interventions are less gross.)
In other words, you have to trust your research. If you really, truly believe that what you’re studying is real, it doesn’t make any sense not to be doing it.
While neither I nor (thankfully) Marshall would tell anyone else to copy us, I think it’s fair that I experiment on my own body.
At the same time, we’re also running trials on several of these interventions at my lab in Copenhagen. The results are starting to show what works – and what doesn’t – to improve our health as we get older, and I’m incorporating the successes into my own routine.
So, here are the seven experiments I hope will keep my body young for longer. We’ll see in 30 years if they worked.
1. Take NR supplements
Getting older sets off a war in our bodies: every day, our genomes are subjected to molecules that damage or modify our DNA, then our many enzymes rush in to try to repair it.
One of the molecules we need for DNA repair is called nicotinamide adenine dinucleotide (NAD) – and the more we use it, the more we lose it.
Thankfully, there’s a supplement that can increase your NAD levels: a molecule similar to vitamin B3 called nicotinamide riboside (NR), something I take every day.
It’s become very popular with ageing researchers like me, but it’s also available to buy over the counter – as is the similar supplement nicotinamide mononucleotide (NMN).
These supplements are particularly good if you’re suffering from a condition that causes inflammation, like Parkinson’s or Alzheimer’s.
In longevity medicine, we still need studies to tell us what the long-term effects of these supplements will be – so, as a doctor, I can’t yet recommend them.
But, so far, studies looking at the impacts of NR on these diseases show there may be some efficacy.
And, in a recent clinical trial, my lab found that NR can reduce inflammation in people with ‘smokers’ lungs’ – chronic obstructive pulmonary disease (COPD).
Inflammation is a strong driver of the accelerated lung ageing that we see in these patients, so minimising it could help them live longer.
2. Intermittent fasting
The benefit of NR is that it’s so easy to do – you pop a pill, and you’re done. But the current frontrunner of my experiments is intermittent fasting.
It’s a diet that’s also known as 16:8 fasting, because you can eat whatever you want during an eight-hour window (mine is noon to 8pm), but then you don’t eat anything for 16 hours.
My lab recently ran a 12-week trial where we compared taking NR, intermittent fasting and exercise in 80 individuals aged 65 and over.
To our surprise, the people who fasted saw the biggest health benefits in terms of body composition, including fat loss and other changes to key biomarkers.
We thought the exercise group might reap the biggest rewards, and this intervention was certainly successful.
When measuring DNA methylation, we found that exercise reduced the participants’ biological ages by an average of four years.
There were further health improvements in this group, like a decreased resting heart rate, that we also observed in the fasting group.
But in the fasting group the oldest participants also came out with biological ages that were 10–15 years younger than at the start of the trial.
We measured this by using artificial intelligence (AI) to analyse changes in blood values across 29 different markers, such as haemoglobin and albumin. That’s a big impact, after just 12 weeks.
The fasting group also lost between 12–20 per cent of their body fat during the trial. That’s comparable to the ‘skinny jab’, Ozempic – and it may even work in the same way.
(Ozempic, originally designed to treat diabetes, contains GLP-1 receptor agonists that suppress your appetite).
Fasting, and losing weight as a result, leads to a reduction in almost all age-associated disease risks.
This research isn’t peer-reviewed or published yet, so conclusions should be taken with a pinch of salt. But that’s what the data says, and it’s what I’m doing.
If you’re wondering, NR didn’t show much of an impact on biological age in this trial, aside from reducing signs of inflammation. In terms of reducing your biological age, intermittent fasting came out top, then exercising, then taking NR.
However, I wouldn’t recommend intermittent fasting for the elderly, or anyone with osteoporosis or sarcopenia, as fasting can cause loss of muscle and bone mass. We think these people will need to combine fasting with exercise, so we’re investigating this in a follow-up trial.
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3. Prioritise your social life
It may sound wishy-washy, but putting my friends and family first is one of the best things I’m doing for my health.
Why? Because staying socially connected is one of the most powerful ways to protect yourself against the effects of ageing.
We know that the risk of most chronic diseases increases as we get older. But one condition that doesn’t follow this trend is depression, which affects people at a steady rate throughout life.
That means it’s not just something that impacts older adults – it’s just as relevant when we’re young.
While the biological mechanisms aren’t fully understood, we do know that depression raises your risk of developing many other chronic conditions. And one of the biggest risk factors for depression is isolation.
So, by nurturing your social life, you’re not just boosting your mood – you could be cutting off a major contributor to long-term illness.
Studies on the links between social life and physiology tend to find that the more social you are, the less inflammation you have in your body and the lower your resting blood pressure.
One study even found that social isolation was more likely to cause high blood pressure – a condition that can lead to heart attacks – than having diabetes.
The 80-year-long Harvard Study of Adult Development, which tracked 268 men across their lives, reached similar conclusions – that loneliness is as bad for your health as smoking or alcohol while, on the other hand, people with strong social relationships live longer.
The researchers behind the study think a key reason could be that interacting with other people delays cognitive decline, including conditions like Alzheimer’s.
For me, social life is such an important anti-ageing intervention that I plan my other experiments around it.
For example, with intermittent fasting, some studies indicate the best time to break your fast is the morning, in terms of burning more energy and reducing inflammation (though research is still ongoing).
Based on that, you might make your eating window 7am to 3pm – but, socially speaking, that can be difficult.
In my family, eating together is a social ritual – breakfast is the more stressful time of day when we’re getting everyone out to school, but dinner is when we come together and spend time with each other. Dinner is also when I see my friends, so skipping breakfast is the easier sacrifice.
4. Drink coffee
If you need an excuse to drink more coffee, I have one for you. You may already know that drinking coffee is linked to a reduction in most age-associated diseases, including cardiovascular disease and dementia. But many people don’t know that the benefits just keep on increasing the more you drink.
In fact, four to five cups a day appears to be best. (After five cups, the benefits level off – more isn’t bad, but you might start impacting your sleep.)
For now, we can identify the effects of coffee, but not the cause. It’s difficult to pinpoint the exact molecules that make coffee so good, in terms of health benefits.
Think of it like cigarettes – it’s difficult to pinpoint the exact molecule that makes them bad, but they definitely are. It’s the combination of several ingredients that has such a strong impact.
It’s similar with coffee – we don’t know why it’s beneficial, although we do have a good idea: a group of molecules known as polyphenols and flavonoids.
Caffeine is probably another important part, so drinking decaf will still bring benefits but not the full suite.
5. ...With lots of cream in it
I’m not just saying this because it tastes good: having fat alongside my coffee may actually increase its benefits for my body.
There are studies showing that when you add milk to your coffee, your uptake of polyphenols and flavonoids (those molecules that make coffee so good for you) increases, perhaps because these molecules dissolve better in fat. By that logic, it’s even better to have cream in your coffee than low fat milk.
Generally, having a good source of healthy fats and protein is important in your diet. There are association studies showing that if your energy input comes more from fat than carbohydrates, your overall mortality risk is reduced. Fat isn’t something to fear.
Carbohydrates, on the other hand, get converted to sugar in our bodies – and that’s not good. (More on this below.) I try to avoid having a lot of carbohydrates.
How much carbohydrate you should eat varies depending on your activity levels. If you have to bike 20km (12 miles) to work every day, then you can eat more.
But if you don’t have a job that requires a lot of physical activity, then you may not need as many carbohydrates in your diet. And let’s face it, working in a lab isn’t exactly the Tour de France.
6. Eat chocolate... but avoid sugar
Again, this isn’t just a bad habit I’ve disguised as an anti-ageing hack: chocolate contains many of the same molecules as coffee, so – potentially – is great for lowering my biological age.
It’s not as well studied as coffee, because fewer people eat chocolate every day compared to a huge, global population of coffee drinkers. It also contains less of those important polyphenols and flavonoids. But, as far as easy anti-ageing interventions go, it’s a good one.
The downside? It’s got to be dark chocolate if you want to get the benefits without the risks. Sugar, which most white and milk chocolate contain significant quantities of, is really bad for you.
The bottom line: sugar is a molecule that stimulates growth. And while that sounds good, too much growth means you lose your stem cells and inhibit pathways that are good for ageing. Sugar can also stimulate cancerous growth.
Even though I’m not actually the biggest chocolate eater (I make up for any shortfalls with coffee), I do love cake. But, sadly, I can’t swing that as an anti-ageing experiment, so I sacrifice this molecule-lacking sweet treat.
7. Control your blood sugar
I have a sweet tooth, so even without cake I have too much sugar. (Reducing my biological age is important, but I can’t – and don’t want to – shut myself off from the joys of life, especially if I’m already limiting myself to an eating window.)
So, I take metformin: a medication, designed as a diabetes drug, that reduces my blood sugar.
When you reduce your blood sugar you set off a chain of events in your body – and one of the most important of these is a process called autophagy.
It’s a kind of recycling process that degrades old parts of your cells and optimises everything, and it also appears to have mitochondrial function so generates the energy your body needs to power its cells. Having high blood sugar counters those benefits.
That’s where metformin comes in. In 2013, one of the studies I helped to conduct showed that mice taking the drug lived longer.
Although studies on other strains of mice have not been able to find a similar effect on lifespan, a 2024 study on monkeys then showed that metformin may reverse primate brain ageing by as much as six years.
In fact, when given metformin, the monkeys displayed enhanced cognitive ability and had a better-preserved brain structure.
These are just a few studies amid a now-large library of research into metformin’s impact on ageing and age-associated diseases.
What we’re still missing, though, is a trial focused on giving metformin to the healthy elderly – but that’s potentially on the way.
The existing studies indicate that metformin reduces many of the risk factors that come with age. The molecular mechanism of why this would work is well understood, but some are still debating if it actually does.
By the time we reach a conclusion, my own health may indicate what the answer will be.
As told by Noa Leach, Special Projects Editor at BBC Science Focus.
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