Biological age
Am I ageing faster than my birthday? What trials show about changing your biological age
Quick answer
Partly, yes. Biological age is an estimate based on markers such as chemical tags on your DNA. In randomised trials, two years of moderate calorie restriction slowed one measure of the pace of ageing. In adults over 70, a daily omega-3 supplement slowed several epigenetic clocks by up to four months over three years.
You are 47. You sleep six hours, run on coffee and back-to-back meetings, and some mornings you feel ten years older than your passport says. You may be right. The good news is that how fast you age is not fixed.
What is biological age?
Your genes are the hardware. Epigenetics is the software: chemical tags, mainly DNA methylation, that switch genes up or down. These patterns shift with age, and also with how you eat, move, sleep and handle stress.
An epigenetic clock reads those patterns and estimates an age. If the clock says 52 and you are 47, your body may be ageing faster than the calendar. There is no single gold-standard clock yet, and different clocks can give different answers.
What randomised trials have shown so far
| Trial | Who took part | What they changed | What happened |
|---|---|---|---|
| CALERIE (Nature Aging, 2023) | 220 healthy adults without obesity, 2 years | Aimed to eat 25% fewer calories | The pace of ageing (DunedinPACE) slowed. The effect was small, and two other clocks did not change significantly |
| DO-HEALTH (Nature Aging, 2025) | 777 adults aged 70+, 3 years | Omega-3 1 g/day, vitamin D 2,000 IU/day, home exercise 3 times a week | Omega-3 slowed several clocks by up to 4 months. All three together worked best on one of four clocks |
| Fitzgerald et al. (Aging, 2021) | 43 healthy men aged 50–72, 8 weeks | Diet, sleep, exercise and relaxation coaching, plus probiotics and plant nutrients | Epigenetic age 3.23 years lower than the control group. A small pilot trial in men only |
What most people miss
The number is not the goal. Clocks disagree, and a single result is one estimate among many. What changed in these trials was ordinary behaviour: eating a little less, moving more and resting better. Those habits protect your heart, brain and metabolism whatever any clock says.
So use biological age as a starting conversation, not a scoreboard. Your blood pressure, waist size, fitness and sleep tell you just as much.
Where to start this week
The British Society of Lifestyle Medicine groups healthy living into six pillars: healthy eating, physical activity, sleep, mental wellbeing, healthy relationships and minimising harmful substances. Pick one and make it small.
- Eat: stop eating when you are comfortably satisfied, not full. The CALERIE effect came from modest, steady restriction, not crash diets.
- Move: add three short sessions of strength or brisk movement to your week. DO-HEALTH used just 30 minutes, three times a week.
- Rest: protect a fixed wake-up time for the next seven days, then build your sleep around it.
FAQs
Is a biological age test worth it? It can be a useful motivator if a doctor explains it alongside your other results. On its own it is not a diagnosis.
Can supplements reverse ageing? No supplement reverses ageing. Omega-3 showed a modest effect in adults over 70. Check with your doctor before starting any supplement.
How quickly can biological age change? A small eight-week trial showed a change, but most evidence comes from trials lasting two to three years. Think in seasons, not weeks.
For the years that matter, Dr Lwin
This article is general education, not personal medical advice. If you have symptoms or concerns, speak to your GP.