Cells & DNA

Telomeres, mitochondria, senescence and NAD , aging at the cellular level.

60 answers, from 415 studies

Last updated: July 2026

Key questions

Does gene therapy with klotho or follistatin work against ageing?

Gene therapy with Klotho shows promising results in mice and cells, but there are no human clinical data yet. The available…

Preliminary evidence

Does sulforaphane from broccoli sprouts work against ageing?

Sulforaphane has impressive effects on ageing processes in laboratory and animal research, but whether this also holds true in…

Preliminary evidence

Does fasting help your cells clean themselves up?

Fasting demonstrably activates the cellular clean-up pathway; for prolonged fasting, it can also accelerate muscle loss, so…

Yes · Preliminary evidence

Does chronic inflammation accelerate the ageing of your cells?

Chronic inflammation demonstrably accelerates cellular ageing through a negative spiral that is difficult to break. The best…

Why do some cells stop dividing as you age?

Cells stop dividing as a protection against damage and cancer, but the accumulation of such stopped cells contributes over the…

What do zombie cells do to your aging?

Zombie cells accelerate ageing by secreting inflammatory substances that damage surrounding tissue. Therapies to remove or…

Can an epigenetic age test really tell you how old your body is?

An epigenetic age test provides a meaningful indication of biological ageing, but is not yet a definitive verdict on your…

Moderate evidence

What does a vitamin D deficiency do to your DNA?

A vitamin D deficiency is associated with greater DNA damage, especially in people with an additional risk factor. Make sure…

What is the relationship between cancer and senescent cells?

Senescent cells initially protect against cancer, but when they accumulate they can actually promote tumour growth through…

What are the hallmarks of aging, exactly?

Aging follows nine recurring biological patterns, from telomere shortening to disrupted cell communication, which together…

Why do cells lose their ability to repair themselves over time?

Cells lose their repair capacity through a combination of declining energy stores, impaired DNA repair and the accumulation of…

What does caffeine do to your cells and their repair process?

Caffeine disrupts the guardians and repair mechanisms of DNA damage in cells, but what this means for ordinary daily coffee…

Can eating too little actually damage your cells?

Eating moderately less probably helps your cells, but eating too few calories for too long or too severely can actually damage…

Preliminary evidence

Why do damaged cells sometimes multiply instead of cleaning themselves up?

Damaged cancer cells survive by actively blocking or redirecting their own self-cleaning and self-destruction mechanisms. This…

Does dehydration make your cells age faster?

There are biologically plausible indications that dehydration harms cells, but whether simply not drinking enough accelerates…

Can heat, such as a sauna, damage your cells or actually make them stronger?

Moderate heat, such as a sauna, prompts cells to protect themselves and, with repeated exposure, may even make them somewhat…

What is the difference between cell division and cellular ageing?

Cell division and cellular ageing are related but not the same: dividing too many times leads to senescence, but ageing also…

Can certain fungi or bacteria in your gut influence your cellular ageing?

Yes, certain gut bacteria and their metabolic by-products can accelerate cellular ageing, but most of the evidence still comes…

Does red light therapy really have an effect on your cells?

Based on the available sources, we cannot answer this question fairly: there is not a single study on red light therapy…

How does air pollution damage your cells from the inside?

Air pollution damages your cells from the inside through oxidative stress: fine particulate matter causes an excess of harmful…

What is apoptosis and why is programmed cell death beneficial?

Apoptosis is a well-supported, indispensable clean-up mechanism that protects your body against damaged, redundant or infected…

Why do damaged proteins accumulate in your cells as you age?

With age, the systems that clear damaged proteins become less and less efficient, while damage to proteins actually increases.…

What does alcohol do to your cells and DNA in the long term?

Prolonged alcohol use damages cells and DNA in multiple ways simultaneously, from oxidative stress in the liver to broken DNA…

Can diet protect your DNA from damage?

Diet has a real effect on DNA protection: a plant-based eating pattern and adequate folate and selenium demonstrably help,…

Yes · Moderate evidence

What is the role of inflammation in cellular ageing?

Inflammation and cellular senescence reinforce each other in two vicious cycles, leading to tissue damage and age-related…

Does resveratrol really help protect cells against ageing?

Resveratrol protects cells impressively in the lab, but whether that also works in practice for you is uncertain: the body…

Preliminary evidence

What are senescent cells and why are they bad for you?

Senescent cells are damaged cells that stop dividing but continue to live and chronically inflame their surroundings. They…

What does chronic stress do to your DNA?

Chronic stress damages your DNA through multiple pathways simultaneously, and this is biologically well supported. How large…

Why are cells damaged when they receive too little oxygen?

Oxygen deprivation damages cells through multiple simultaneous pathways: energy deficit, toxic accumulation of calcium and…

What is glycation and how does sugar damage your cells from the inside?

Sugar damages your cells through a chain of chemical reactions that affect proteins, power plants, and small blood vessels.…

Can fasting really rejuvenate your cells?

Fasting has clear cell-rejuvenating effects in animal research, but in humans the evidence is still limited to small studies…

Preliminary evidence

What is the Horvath clock and why is it so well known?

The Horvath clock was the first biological age measure that worked broadly across virtually all tissues, and that is what…

Can smoking permanently damage your DNA?

Smoking damages your DNA in multiple ways simultaneously and leaves recognisable mutation patterns in at least 17 types of…

What are free radicals and what do they do to your cells?

Free radicals damage your DNA, proteins and cell membranes every day, and play a proven role in ageing and various diseases.…

How does a cell know when to stop dividing?

Cells stop dividing through built-in emergency brakes that respond to damage, stress, or viruses. This system is protective in…

Does caloric restriction actually make your cells younger?

Caloric restriction slows ageing processes in cells, but whether your cells actually become younger as a result has not yet…

Can DNA damage in your cells repair itself?

Your cells repair DNA damage constantly and on a large scale, but this capacity is not unlimited: complex or repeated damage…

What does autophagy do for ageing and disease?

Autophagy is a genuine part of the ageing process and plays a role in many age-related diseases, but the translation into…

Can you measure autophagy in your body?

A reliable, practically deployable test for autophagy does not yet exist. If you want to know how actively your cells are…

Does exercise activate autophagy?

Exercise activates autophagy in muscle cells through well-described mechanisms, but most of the evidence comes from animal and…

Yes · Moderate evidence

How do telomeres protect your DNA?

Telomeres protect your chromosome ends through a system of proteins that simultaneously prevents false alarms and harmful…

What does telomerase do to the length of your telomeres?

Telomerase keeps telomeres intact for longer by compensating for shortening during cell division, but in most body cells the…

Why do your telomeres get shorter as you age?

Telomere shortening is part of life: every cell division costs a piece. But smoking, chronic stress, and sleep deprivation…

What is hormesis (what doesn't kill you makes you stronger)?

Mild, periodic stress can make cells more robust through well-described biological mechanisms, but whether humans can…

Do sirtuins actually do anything against ageing?

Sirtuins play a biologically demonstrable role in ageing, but whether you can meaningfully influence them with supplements has…

Yes · Moderate evidence

What is mTOR and why does it matter in ageing?

Inhibiting mTOR strongly extends lifespan in mice, but whether you can achieve that as a human through drugs or diet has not…

What does insulin do to the ageing process?

Chronically high insulin signalling contributes to accelerated ageing and age-related diseases; maintaining your insulin…

Does fisetin from strawberries really work as a zombie-cell cleaner?

Fisetin demonstrably clears zombie cells in lab and mouse research, but whether this also works in humans and is safe has not…

Preliminary evidence

Can you have your telomeres measured, and is there any value in doing so?

Having your telomeres measured is possible, but the result of a commercial blood test is difficult to interpret. Measurement…

Yes · Moderate evidence

Do I inherit my life expectancy from my parents?

You inherit a biological advantage from long-lived parents, but genes account for only approximately 39% of differences in…

What are mitochondria, and can you make them younger or more energetic?

Regular exercise is by far the best-supported means of keeping mitochondria healthy; NAD+ supplements sound appealing but have…

Yes · Strong evidence

Can you counteract age-related DNA damage through your lifestyle?

Based on the available source, it cannot be said whether lifestyle counteracts age-related DNA damage; the study concerns…

Insufficient evidence

Does clearing senescent cells with senolytics help against ageing?

Senolytics show impressive results in mouse studies, but in humans the evidence is too thin for use outside clinical trials.…

Preliminary evidence

Do my stem cells run out as I get older?

Your stem cells do gradually decline in number and function, affecting muscle repair, brain function and other tissues. There…

What is epigenetics and can you influence your genes?

Lifestyle and environment genuinely influence how your genes work, but concrete applications for healthy people do not yet…

Yes · Strong evidence

What is oxidative stress and how serious is it really?

Oxidative stress is a real biological process that causes damage to cells and contributes to ageing, but how large a role it…

Can you clear out "zombie cells" to slow down ageing?

In mice, clearing zombie cells clearly works, but in humans a health benefit has not yet been proven. It is too early to take…

Moderate evidence

What are "zombie cells" and how do you get rid of them?

Zombie cells clearly play a role in ageing, but no proven treatment yet exists for humans. Keep an eye on the field, but for…

Yes · Strong evidence

What is autophagy and can I switch it on myself?

Fasting and exercise are the best-supported ways to stimulate autophagy, but how to apply this most effectively and safely…

Yes · Strong evidence

Can you tell from your DNA which diseases you are at greater risk of, and how is that measured?

Your DNA and certain proteins in your blood provide a useful picture of your predisposition to heart disease and other common…

Yes · Strong evidence

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