Four years ago I wrote myself a letter. A strange thing to do, you might think. But at the time I was desperate. My health was in dire straits and, aged just 27, I was living a half-life.

Profound migraines left me trapped in my bed for days. I had terrible irritable bowel syndrome (IBS) – swinging between constipation and diarrhoea – and I was so bloated I often had to wear trousers two sizes bigger than my usual.

I’d also been afflicted by pneumonia, asthma, rosacea, unexplained skin rashes all over my body, chronic sinusitis and tonsillitis (the latter so bad that for 15 straight months, between the ages of 18 and 21, I was prescribed antibiotics every single month, which inevitably played havoc with my gut).

At one point I took between five and ten prescription medications every day, yet they barely kept a lid on my conditions.

In that letter, I wrote of the chronic pain I felt, my misery at not being able to take part in social activities, of feeling like I inhabited an old woman’s body.

Yet studying for my PhD in biomedical sciences at the time, I knew there had to be an answer beyond the medications. The researcher in me took over, and in that letter I wrote how I knew, somehow, I’d get better.

I researched furiously into the latest thinking into achieving physical wellness. Again and again, scientific papers came back to the same answer – everything starts in the gut.

This was especially relevant to me because, as a child, I’d been naturally skinny, and the GP told my mother to feed me anything – junk food, chocolate, anything! – to fatten me up. And these foods became a big part of my diet – and remained so into adulthood.

At 27, Dr Lara Hemeryck felt as though she was living in an old woman’s body. So she turned her own body into a research project and began exploring the field of longevity science

My cravings for junk became so strong that, at my worst, I would be satisfied with crisps for dinner. I loved fried food – any beige type of food was catnip to me.

However, I discovered my poor diet had fuelled inflammation in my gut and all over my body. I vowed to change, and began to treat my own body like a research project.

I took a DNA test and learned I had certain gene mutations that affected the way I processed food – more of that later.

I tried every diet going, but none worked so I decided to listen to my body: how was it reacting to certain foods? I cut out processed foods and relied on meat, fish, eggs and cooked veg.

After a few months I started to slowly reintroduce whole, unprocessed foods, using my symptoms as a guide. After six months, my IBS had vanished.

Even more dramatically, I’d come off all my medications. My sinusitis cleared up, my migraines disappeared, my lungs felt stronger, even the rosacea on my face improved. I had energy to exercise. I finally felt young.

I went on to become a stem cell researcher at KU Leuven University in Belgium. In 2022, I created the first ‘organoid’ tooth, which will hopefully replace artificial dental implants one day. Though incredibly satisfying, I wanted to do more to help people learn how our body can rejuvenate itself, as mine had.

So I began to explore the new field of longevity science. I also set up a communication agency, to translate complex science into actionable tips, so people can take ownership of their health as I did.

For as I’ve learned, small tweaks can make the biggest difference. Changes to our diet, sleep and exercise routines can influence our genes, shape our gut microbes (key to our health), regulate inflammation, and even signal to your cells how fast to age.

Some of these things will be familiar to Daily Mail readers – such as always cooking your tomatoes, to make it easier for your body to absorb the compound lycopene, which is said to help prevent certain cancers. And lifting weights is vital, as using muscles produces molecules called myokines, which protect your brain and strengthen your immune system.

Small tweaks – such as always cooking your tomatoes to make it easier for your body to absorb the compound lycopene – make the biggest difference

Lifting weights is vital, as using muscles produces molecules called myokines, which protect your brain and strengthen your immune system

Also, add bursts of movement to your day – skip the lift and take the stairs, for example – as frequent movements stress the body, in turn boosting the function of the mitochondria (the energy generators in your cells) which can help slow ageing.

Here are some science-backed ways to boost longevity that you might not have come across…

EAT ‘METHYL’ FOODS TO FUEL REPAIR PROCESSES

The process where the body converts food into energy and vital compounds is called methylation. It’s important for DNA repair, energy production and the creation of chemical messengers in the brain. It also affects whether genes are turned on or off.

However, around 40 per cent of us have a mutation in the MTHFR gene, which can impair methylation. This can make it harder for the body to process folate, a B vitamin which can affect energy, mood and heart health. It can also make the body’s detoxification process trickier.

A DNA test will reveal if you have this mutation (as I have), but as it’s so common it’s worth all of us eating foods rich in methyl to boost the methylation process.

So increase your intake of beetroot, shiitake mushrooms, dark leafy greens and cruciferous veg (broccoli, cauliflower and kale).

USE RED LIGHTS IN YOUR BEDROOM

Poor sleep compromises glucose regulation – your body’s ability to process sugar – raises inflammation and impairs night-time detoxification processes.

As you know, blue light from phone screens before bed is bad for sleep, as it suppresses melatonin, the hormone that signals it’s time to wind down (it activates cells in the eye and tricks them into thinking it’s daytime).

But modern LED light bulbs have the same effect. Even brief exposure after sunset can reduce melatonin by 50 per cent.

Ideally, avoid screens and bright lighting in the hours before bed. And use red light bulbs in your bedside lamp. Red-tinted reading lights are also available. Some research indicates this can boost melatonin and regulate your sleep cycle.

COOK CHICKEN ON THE BONE

Skin-on, bone-in poultry is better for you, thanks to the connective tissue, collagen and extra minerals it contains. Thigh meat has more collagen than breast as it’s closer to the bones.

Consuming collagen really can help: a 2018 study in Nutrients found an increase in collagen consumption improved the appearance of skin hydration and elasticity. The Nutrition Journal in 2016 reported it can even help arthritis pain and stiffness.

Adapted from Living Young by Lara Hemeryck & Anastasia Mabel (Michael O’Mara, £12.99). Order for £11.69 (valid to Dec 16, 2025; UK P&P free on orders over £25) at mailshop.co.uk/books or call 020 3176 2937.