When most people think of ageing, they imagine grey hair, wrinkles, and perhaps a slower pace of life. But scientists are discovering that ageing is not just about the number of candles on your birthday cake, it’s a complex process happening deep inside our cells.
A new scientific review pulls together years of research to show that certain infections –whether viral, bacterial, or even parasitic may push our bodies towards ageing faster than nature intended. Here’s what you need to know, explained in everyday language.
The Idea in a Nutshell
Many germs don’t just make us ill for a week or two. They can stay in the body for years, quietly interacting with our cells and immune system. Over time, this can:
- Damage cells and tissues
- Exhaust the immune system
- Change how our genes work
- Speed up processes linked to age related diseases
1. Stubborn Inflammation
When an infection hangs around, the immune system stays switched on. This constant, low level inflammation can slowly damage tissues. It’s like a fire that never goes out completely, the smoke and heat keep wearing things down.
2. Cellular Senescence
Sometimes, inflammation or direct damage from a germ causes cells to stop dividing forever. These “senescent” cells don’t die, they linger, releasing chemicals that can harm nearby healthy cells.
- Some microbes even force cells into this state to help them survive.
- Other times, these old cells become easier for germs to infect, creating a vicious cycle.
3. Mitochondrial Hijacking
Mitochondria are like batteries for our cells. Some viruses and bacteria take over these batteries to make the raw materials they need to reproduce.
- This often forces cells into a “quick and dirty” way of making energy (called the Warburg effect), which is linked to cancer and ageing.
- Infections can also create harmful molecules called reactive oxygen species (ROS). In small amounts, ROS fight infection, but in large amounts, they damage cells and even help some viruses multiply.
4. Hacking Our Signals
Viruses and bacteria have evolved proteins that can interfere with our own cell signals including those that control cell growth, repair, and death.
- One study found over 120 different viruses whose proteins directly mess with human proteins linked to ageing.
- Sometimes two infections together such as flu and Epstein-Barr virus can have an even greater effect.
5. Molecular Mimicry
Some germs make proteins that look almost identical to our own. This “molecular mimicry” lets them sneak into important pathways undetected.
- For example, one virus makes a hormone look-alike that can mess with blood sugar regulation.
- Others mimic structural proteins, potentially damaging collagen and the immune system.
6. Telomere Shortening
Telomeres are the protective “caps” at the ends of our chromosomes, a bit like the tips on shoelaces. They naturally shorten as we age. But certain infections can speed up this shortening.
- COVID survivors in one study showed biological ageing over 10 years faster than expected.
- Some viruses even weave their DNA into telomeres, making them unstable.
7. An Ageing Immune System
Over a lifetime, repeated or long-lasting infections can “wear out” the immune system, a process called immunosenescence.
- Chronic infections can exhaust T cells, the “soldiers” of our immune system.
- They can also reduce the number of fresh, naïve T cells, making it harder to fight new threats.
- In some cases, a single persistent infection, such as cytomegalovirus, can dominate a huge chunk of your immune resources.
Why This Matters for Patients and Families
Understanding that infections may accelerate ageing isn’t about fear it’s about knowledge. It might explain why some people develop long-term fatigue, memory issues, or other health problems after infections like COVID-19, glandular fever, or Lyme disease.
Researchers are now exploring ways to:
- Target persistent pathogens more effectively
- Remove harmful senescent cells (“senolytic” therapies)
- Support mitochondrial health
- Boost immune resilience in later life
Bottom Line
Ageing is not just about time, it’s also about what happens inside us. Persistent or repeated infections may be one of the hidden accelerators of the ageing process. Looking after our immune health, preventing infections where possible, and treating chronic infections seriously could all help protect not just our years, but the quality of them.
Disclaimer: This article is for general informational and educational purposes only. It is not medical advice and should not replace guidance from a qualified healthcare professional.
Sources: Some of these concepts are being actively researched by scientists such as Dr Amy Proal, President and Chief Scientific Officer at the PolyBio Research which investigates how persistent infections can contribute to chronic illness and accelerated ageing
Long Covid Journey 