Why your body ages: 9 scientific causes

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Why do you feel different at forty than you did at twenty? Science has a clear answer to this. Researchers have discovered nine biological processes that together determine how quickly your body ages.

The good news: you can influence some of these processes yourself through your daily habits.

In this blog, we explain in simple terms what happens in your body as you age and what concrete steps you can take to age more healthily.

What is aging? 

Aging isn’t just one process. It’s the sum of tiny changes in your cells that accumulate over the years. A groundbreaking scientific review, published in the journal Cell, brings these changes together into nine so-called "hallmarks" or characteristics of aging. You can think of this research, The Hallmarks of Aging, as a roadmap: it shows where aging starts in your body and where you can make a difference with healthy habits. 

We’ll go through the nine characteristics one by one below. No complicated jargon, just practical tips.

The 9 signs of aging, simply explained

1. DNA damage

Every day, the DNA in your cells experiences small damages, caused by things like sunlight, stress, and environmental factors. Your body automatically repairs most of the damage, but over time, some of it accumulates.

Tip: protect your skin from too much sun, limit exposure to cigarette smoke, and choose unprocessed foods full of antioxidants, like vegetables and fruit whenever possible.

2. Shorter telomeres

Telomeres are the protective caps at the ends of your chromosomes, kind of like the plastic tip on a shoelace. Every time a cell divides, they get a little shorter. If they become too short, the cell stops dividing.

Tip: research shows that regular exercise and enough sleep are linked to longer telomeres. So try to include a block of walking or some sport in your daily routine.

3. Changes in your epigenetics

Besides your DNA itself, the way your genes are "turned on and off" also changes. This is called epigenetics, and it's partly influenced by your lifestyle.

Tip: diet, exercise, and stress management all affect your epigenetics. A varied diet with enough folic acid, vitamin B12, and omega-3 supports this process.

4. Less efficient "cleanup" of proteins

Your cells constantly make proteins and break down damaged ones. Over the years, this cleanup system becomes less efficient, allowing damaged proteins to accumulate.

Tip: periods of not eating, like not eating for 12 to 14 hours at night (also called intermittent fasting), stimulate your cells' natural cleanup process (autophagy).

5. Disturbed nutrient sensors

Your body has built-in "sensors" that respond to the amount of nutrients you take in. Constantly overeating disrupts these sensors and speeds up aging.

Tip: eat in moderation and give your body a break from food every now and then. Calorie restriction in animal studies has been shown to extend lifespan, and moderate, regular eating is already a good step for most people.

6. Less energy from your mitochondria

Mitochondria are the powerhouses of your cells. As you get older, they become less efficient, leaving you with less energy and getting tired faster.

7. Cellular "aging" (senescence)

Damaged cells can go into a sort of sleep mode: they stop dividing but don’t disappear either. A few of these cells are useful, but too many promote inflammation.

Tip: an anti-inflammatory diet, with lots of vegetables, fatty fish, and extra virgin olive oil, helps your body keep these processes in balance.

8. Exhausted stem cells

Stem cells renew your tissues. Over the years, their number and functionality decline, which slows down wound healing and muscle recovery. 

Tip: Strength training and enough protein intake encourage your body to actively repair and renew muscle tissue.

9. Disrupted communication between cells

Cells constantly "talk" to each other through hormones and signaling molecules. As we age, there’s often a slightly elevated, low-level inflammatory state in the body, also known as "inflammaging." 

Tip: Getting enough sleep, reducing stress, and staying active help keep this cell communication healthy.

Why this is important for you

You can't stop aging, but scientific research shows that you can slow down the process. Small, everyday choices when it comes to diet, exercise, sleep, and stress have a measurable effect on these nine processes. The good news is: you don't have to tackle everything at once. Start with one habit that fits you and build from there.

Practical step-by-step plan to age more vibrantly

• Eat enough healthy foods daily, like vegetables and fruits for antioxidants and enough protein.
• Get at least 30 minutes of exercise per day, like walking or cycling.
• Maintain a regular sleep schedule of 7 to 9 hours per night.
• Give your body an occasional break from eating, like having a longer overnight fast.
• Do strength training at least twice a week to support muscles and stem cells.
• Reduce chronic stress with breathing exercises or a walk outside.

Frequently asked questions about aging more vibrantly

Can you really slow down aging with lifestyle?

Yes, scientific research shows that diet, exercise, sleep, and stress management affect multiple biological aging processes, such as your telomeres and your mitochondria.

At what age does cellular aging start?

Cellular aging starts already in young adulthood, but the effects only become noticeable after your thirties or forties in terms of energy, recovery, and skin.

What’s the quickest thing I can do to feel more alive?

Getting enough sleep and moving daily often gives noticeably more energy within just a few weeks, as they positively influence your mitochondria and stress levels.

Does fasting really help against aging?

A longer nightly eating pause (12 to 14 hours) can stimulate your cells' natural cleaning process. Always consult a doctor or dietitian if in doubt, especially if you have underlying health issues.

Lifestyle Habits

Lifestyle Habits helps you with practical, easy-to-access digital products in the areas of nutrition, self-development, and simple money management – think courses, ebooks, and step-by-step plans to turn small, conscious lifestyle habits into lasting change. This article is based on PMC - NIH 'The Hallmarks of Aging' (June 6, 2013). It was written by the founder of Lifestyle Habits, drawing on years of practical experience and self-study in personal development, supplemented with reliable sources and scientific research. Curious about who’s behind Lifestyle Habits and what the brand stands for? Check out the About Lifestyle Habits webpage.

The content of Lifestyle Habits is intended solely for general, educational, and informational purposes and is meant to serve as inspiration. No personal (medical or psychological) advice is given, and no health claims are made. No rights can be derived from the content. If you have questions about your personal situation, health, or well-being, it's always wise to consult a qualified specialist.