What you need to know about the 12 hallmarks of ageing

Nov 27, 2023

Article highlights

  • Ageing is the natural and gradual process of becoming older over time

  • We can measure ageing by chronological (how long we’ve been alive), and biological (reflecting physical and functional) health.

  • The twelve hallmarks of ageing can determine our biological age, directing healthy lifestyle changes to improve quality of life and delay the onset of chronic disease.

  • Some aspects of ageing are beyond our control because they are genetic, but our lifestyle and environments influence the rate and quality of ageing.

The ageing process

Ageing refers to the natural and gradual process of becoming older over time. It is a complex and multifaceted phenomenon that affects every living organism. While some aspects of ageing are beyond our control, lifestyle choices can influence the rate at which ageing occurs and the quality of life in older age. The visible effects that we regard as ageing in everyday life are actually just 'side-effects' of much more complicated processes happening within the body on a cellular level. 

Measuring age

The measurement of ageing is a complex process but can broadly be measured in two ways. 

Chronological age is defined by the number of years we have been alive since birth and is the most common and straightforward way to measure age. It doesn't, however, take into account factors like genetics, lifestyle and overall health.

Biological age is determined by a person's overall physical and functional health, rather than the number of years since birth. It’s a measure of how well our body and organ systems are functioning on a cellular and physiological level compared to expected norms for that age (1). Biological age can be influenced by various factors, including genetics, lifestyle, diet, exercise, exposure to environmental factors and overall health.

Various methods can be used to estimate biological age, including biomarkers and genetic testing. These tests take into account factors such as cardiovascular health, muscle mass, cognitive function, and the presence of age-related diseases to provide a more accurate picture of our true age in terms of well-being. 

Some people may have a biological age that differs from their chronological age, in which their body and health status may be older or younger than the number of years they have lived.

The twelve hallmarks of ageing

There are twelve characteristics of the ageing process. These interconnected biological processes and mechanisms contribute to ageing (4). The more any of the hallmarks are present, the more the ageing process will accelate. The good news is that reducing any of the hallmarks will slow down the ageing process.

These hallmarks of ageing are grouped into three broad categories: Primary, Antagonistic and Integrative. They represent the level of action your body takes to protect you. For example, primary hallmarks are the primary causes for ageing processes and disease. 

Each hallmark is a target for intervention, and there are many ways to make a change. Some hallmarks listed below include a general tip. Keep in mind these are not personalised so may not work for you and your personal medical background or lifestyle. 

The best way to measure whether interventions work is by consulting your physician and tracking markers of ageing over time - for example, measuring blood pressure or cholesterol levels at regular intervals throughout your life, or just after you start making habits changes. 

Genomic instability - when it comes to our genes, instability means broken or missing hereditary information (2). The danger of genetic instability is that it may result in disease, such as cancer (3). Healthy behavioural changes such as avoiding sun damage and staying active support gene stability and strength.

Telomere attrition - the protective caps at the end of each of our 46 chromosomes (the structures that carry our genetic information inside the cell) are called Telomeres. Telomere attrition is the gradual shortening or loss of these protective caps. It limits how much our cells can divide, slowly decreasing the health and strength in our vital organs (4).

Epigenetic alterations - the study of epigenetics encompasses the behaviours and environmental factors that influence how our genes express themselves (5). When there are epigenetic alterations, the amount of protein generated from each gene by transcribing and translating the DNA may change. Such alterations in gene expression can affect the function of cells, tissues and organs. It also contributes to genetic instability and senescence, which halts cell growth and interrupts physiological function. 

Loss of proteostasis - as we age, damaged portions can’t be renewed or excreted as effectively. Proteins can get misfolded or damaged, so our cells have quality control mechanisms that repair or recycle them. Proteostasis is the regulation of the system that builds, folds, and turns over proteins (4). The accumulation of misfolded proteins is a root cause of age-related diseases such as Alzheimer’s disease. Since sleep is essential for refolding or removal or misfolded proteins, one way to help prevent Alzheimer’s disease is to get enough good quality sleep every night (24).

Disabled macroautophagy – the process where the body recycles and renews old and damaged cell parts. This removes toxic proteins that may contribute to neurodegenerative diseases, while regenerating healthy cells for optimal function. As we age, our autophagy mechanisms slow, which is why it's important to support autophagy with healthy lifestyle choices such as occasional fasting (6). 

Cellular senescence – a process in which a cell ages and permanently stops dividing, but does not die (7). The cell loses the ability to function, repair or die. This leads to a loss of function. Since senescent cells can encourage neighbouring cells to also become senescent, it can start to affect the function of whole organs over time. In order to keep cells working well, it’s important to regularly consume healthy fats, such as omega-3 and lean protein.

Mitochondrial dysfunction - our mitochondria are our main powerhouses, converting the oxygen we breathe and the foods we eat into energy for our cells. When we have dysfunctional mitochondria, it can result in excess fatigue and chronic disease. Clinical trials have shown that some supplements, such as the personalised ones offered by NU, can restore mitochondrial function (8). 

Deregulated nutrient sensing - metabolic pathways, or the way we change food into energy, are active in response to getting enough of the right nutrients. These pathways are essential for our daily function. When we’re young, we need high metabolic activity in order to build our organs and tissues. However, as we get older, the high metabolic activity can also put stress on our cells and contribute to faster ageing. Intermittent fasting may help some people by temporarily inhibiting these metabolic pathways and lowering blood sugar (20).

Stell cell exhaustion - stem cells replace damaged cells, but when they too get damaged, they can lose their ability to renew and their numbers get depleted. Without enough stem cells, our tissues and organs lose their ability to recover from damage and start to fail (9). To promote stem cell reproduction, consider intermittent fasting, reduce sugar intake and exercise regularly. 

Altered intercellular communication -  the cells in our body communicate with each other and can be influenced by bacteria in our gut. This connection is very complex, and even small changes in one system can have negative effects on another body system. Altered intercellular communication advances decline in tissue health and makes us more susceptible to disease. You can improve intercellular communication in your body by eating high fibre, like whole grains and fermented foods, or probiotics and supplements.

Dysbiosis - the microbiome is a community of microorganisms including fungi, bacteria, and viruses. They consist of both helpful and harmful types. When we have dysbiosis, there are more harmful organisms present (19). This can lead to inflammation, increased risk of infection, and age-related disease. There are simple steps to help our healthy bacteria, including focusing on fibre rich foods like vegetables, limiting added sugar, and including more probiotics from supplements, yoghurt, or kefir. 

Chronic inflammation - acute inflammation, such as when we fall and get a wound, can be healthy and helpful for the healing process. When we have chronic low grade inflammation, such as from high stress, excess alcohol, sugar, or fried foods, it's associated with increased morbidity and mortality in the ageing population (10). Inflammation in the body can be reduced with practices such as stress reduction and anti-inflammatory foods and supplements.


Some people inherit specific genetic variations that make them more or less susceptible to certain age-related conditions. For example, some individuals inherit genetic mutations that increase their risk of heart disease, Alzheimer's, or cancer. When it comes to genetic influence on ageing and related disease, the hereditary factors involved include mitochondria (our cell's powerhouse) and DNA variations (11). 

DNA damage accumulates with age and is a key factor in the ageing process. Genetic variations can affect the efficiency of the repair mechanisms, potentially increasing our vulnerability to DNA damage.

It's important to note that while genetics can influence the ageing process and age-related diseases, they do not solely determine our fate. Lifestyle factors, including diet, exercise and environmental exposure also play a crucial role in how we age.

Lifestyle choices

Lifestyle factors have a significant impact on the ageing process and can influence how we age and our susceptibility to age-related diseases. Healthy lifestyle choices promote longevity and well-being as we grow older. Key lifestyle factors that can affect ageing include:

Diet: a balanced and nutritious diet is crucial for healthy ageing. Consuming a variety of fruits, vegetables, whole grains, lean proteins and healthy fats provide essential nutrients and antioxidants that help maintain cellular health and reduce the risk of chronic diseases.

Physical activity: regular exercise is essential for maintaining physical and mental health as people age. Exercise improves cardiovascular health, muscle strength, flexibility and cognitive function. It also helps prevent obesity and reduce the risk of chronic diseases like heart disease, diabetes and osteoporosis (12). 

Stress management: chronic stress often has a negative impact on our physical and mental health. Effective stress management techniques, including mindfulness, meditation and relaxation exercises, can help mitigate the effects of stress, which in turn contributes to healthy ageing.

Social engagement: staying socially active can have a positive impact on our emotional and cognitive well-being. Spending time with friends and family, and participating in community events can reduce feelings of isolation and depression.

Cognitive stimulation: keeping the mind active and engaged through activities like reading, puzzles and learning new skills helps maintain cognitive function and reduce the risk of neurodegenerative conditions, such as Alzheimer's disease.

Quality sleep: adequate and restorative sleep is essential for optimum health. Insufficient sleep contributes to various health issues, including cognitive decline and an increased risk of chronic diseases.

Avoidance of harmful substances: the consumption of tobacco, alcohol, and illicit drugs contribute to a wide range of health problems and accelerate the ageing process.

Regular health check-ups: screenings can help detect and address health issues early, resulting in more positive outcomes.

Environmental factors

Environmental factors, ranging from physical and chemical to social, significantly impact how we age, some of these include:

Prolonged exposure to air pollution can contribute to respiratory problems, cardiovascular disease and cognitive decline in older adults. It can also increase free radicals which can cause cell damage (13). 

Excessive sun exposure over a lifetime can lead to premature skin ageing, skin damage and an increased risk of skin cancer.

Eating nutritious food is crucial for healthy ageing. Poor diet and inadequate nutrition, including too many processed or fast foods, can cause malnutrition, obesity and contributes to a higher risk of chronic diseases.

Access to green spaces and outdoor activities has been shown to enhance physical and mental well-being, and slower biological ageing (14). 

Health implications of age-related disease 

The human lifespan has increased in the last decades, yet our years of being physically and mentally healthy have not kept up. Ageing is a main factor for various diseases, including the heart, brain, and immune system (15). Understanding the most common age-related diseases may help motivate changing our behaviours in order to prevent them. Some of the most common ones include: 

Alzheimer’s disease is the most common neurodegenerative disease in the world. It’s characterised by amyloid plaques, or misfolded proteins between brain cells, which impacts memory and function (15). Alzheimer's is characterised by memory loss, changes in behaviour and impaired mental ability. Alzheimer's is most commonly diagnosed in older adults, typically those over the age of 65 and is progressive, meaning that it worsens over time. 

Parkinson's disease is a neurodegenerative disorder that primarily affects the central nervous system. While Parkinson's disease affects people of various ages, it is more commonly associated with older individuals. It tends to be considered an age-related condition because the risk of developing significantly rises with age (16). 

Arthritis is a common condition that affects the joints, causing pain, stiffness and inflammation. It impacts people of all ages, including children, but it is more prevalent in older adults.

Osteoarthritis is the most common type of arthritis in older adults. This degenerative joint disease occurs when the protective cartilage that cushions the ends of bones wears down over time. Osteoarthritis is strongly associated with ageing, and the risk of developing it increases with age.

Rheumatoid arthritis is an autoimmune disease that can affect people of all ages, but it becomes more severe in older adults. The management of rheumatoid arthritis in older patients can be complicated due to other age-related health issues and the use of multiple medications (17).

Macular degeneration, also known as age-related macular degeneration (AMD), is a progressive eye condition that primarily affects older adults and can lead to significant loss of vision. It is one of the leading causes of vision impairment and blindness in people over the age of 50. Macular degeneration affects the macula, the central part of the retina responsible for sharp and central vision. Age is the most significant risk factor for AMD, with the majority of cases occurring in people over 50. Other risk factors include family history, genetics, smoking, and certain genetic factors (18). 

The risk of heart disease, high blood pressure, and stroke increases with age. Atherosclerosis, or the hardening of the arteries, is a common contributing factor. Age is a significant factor in the development and progression of heart disease. It is more common in older adults - the majority of heart disease-related deaths occur in people over the age of 65. 

Over time, various risk factors for heart disease accumulate, including high blood pressure, high cholesterol levels, smoking, obesity, diabetes and a sedentary lifestyle. Older adults are more likely to have had prolonged exposure to these risk factors, increasing their susceptibility to heart disease.


Ageing is a natural part of human life, but we can decelerate, stop or reverse some hallmarks by pursuing a healthy lifestyle (10). The first step is to get to know yourself on a deeper level and understand how to optimise your biological data, including your genes and gut microbiome. By connecting your key processes like sleep and inflammation, you can set forth on a path towards healthy ageing.


  1. Colloca, Giuseppe, Beatrice Di Capua, Andrea Bellieni, Domenico Fusco, Francesca Ciciarello, Luca Tagliaferri, Vincenzo Valentini, and Lodovico Balducci. 2020. “Biological and Functional Biomarkers of Aging: Definition, Characteristics, and How They Can Impact Everyday Cancer Treatment.” Current Oncology Reports 22 (11). https://doi.org/10.1007/s11912-020-00977-w.

  2. “Genetic Mutations: Overview & Types.” 2022. Cleveland Clinic. Cleveland Clinic. May 24, 2022. https://my.clevelandclinic.org/health/body/23095-genetic-mutations-in-humans.

  3. National Cancer Institute. 2011. “Https://Www.cancer.gov/Publications/Dictionaries/Cancer-Terms/Def/Genomic-Instability.” Www.cancer.gov. February 2, 2011. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/genomic-instability.

  4. López-Otín, Carlos, Maria A. Blasco, Linda Partridge, Manuel Serrano, and Guido Kroemer. 2013. “The Hallmarks of Aging.” Cell 153 (6): 1194–1217. https://doi.org/10.1016/j.cell.2013.05.039.

  5. CDC. 2020. “What Is Epigenetics?” Centers for Disease Control and Prevention. CDC. 2020. https://www.cdc.gov/genomics/disease/epigenetics.htm#:~:text=Epigenetics%20is%20the%20study%20of.

  6. Alirezaei, Mehrdad, Christopher C. Kemball, Claudia T. Flynn, Malcolm R. Wood, J. Lindsay Whitton, and William B. Kiosses. 2010. “Short-Term Fasting Induces Profound Neuronal Autophagy.” Autophagy 6 (6): 702–10. https://doi.org/10.4161/auto.6.6.12376.

  7. NATIONAL CANCER INSTITUTE. 2011. “Https://Www.cancer.gov/Publications/Dictionaries/Cancer-Terms/Def/Senescence.” Www.cancer.gov. February 2, 2011. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/senescence.

  8. Nicolson, Garth L. 2014. “Mitochondrial Dysfunction and Chronic Disease: Treatment with Natural Supplements.” Integrative Medicine (Encinitas, Calif.) 13 (4): 35–43. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4566449/.

  9. Oh, Juhyun, Yang David Lee, and Amy J Wagers. 2014. “Stem Cell Aging: Mechanisms, Regulators and Therapeutic Opportunities.” Nature Medicine 20 (8): 870–80. https://doi.org/10.1038/nm.3651.

  10. Baechle, Jordan J., Nan Chen, Priya Makhijani, Shawn Winer, David Furman, and Daniel A. Winer. 2023. “Chronic Inflammation and the Hallmarks of Aging.” Molecular Metabolism 74 (August): 101755. https://doi.org/10.1016/j.molmet.2023.101755.

  11. Rodríguez-Rodero, Sandra, Juan Luis Fernández-Morera, Edelmiro Menéndez-Torre, Vincenzo Calvanese, Agustín F Fernández, and Mario F Fraga. 2011. “Aging Genetics and Aging.” Aging and Disease 2 (3): 186–95. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295054/.

  12. CDC. 2019. “Physical Activity Prevents Chronic Disease.” Physical Activity Prevents Chronic Disease. 2019. https://www.cdc.gov/chronicdisease/resources/infographic/physical-activity.htm.

  13. Wang, Guoying, Shiming Jia, Xiuli Niu, Haoqi Tian, Yanrong Liu, Xuefu Chen, Lan Li, Yuanhang Zhang, and Gaofeng Shi. 2017. “Total Free Radical Species and Oxidation Equivalent in Polluted Air.” The Science of the Total Environment 609 (December): 1103–13. https://doi.org/10.1016/j.scitotenv.2017.07.233.

  14. Kim, Kyeezu, Brian T Joyce, Drew Nannini, Yinan Zheng, Penny Gordon-Larsen, James M Shikany, Donald M Lloyd-Jones, et al. 2023. “Inequalities in Urban Greenness and Epigenetic Aging: Different Associations by Race and Neighborhood Socioeconomic Status” 9 (26). https://doi.org/10.1126/sciadv.adf8140.

  15. Li, Zhe, Zhenkun Zhang, Yikun Ren, Yingying Wang, Jiarui Fang, Han Yue, Shanshan Ma, and Fangxia Guan. 2021. “Aging and Age‐Related Diseases: From Mechanisms to Therapeutic Strategies.” Biogerontology 22 (2): 165–87. https://doi.org/10.1007/s10522-021-09910-5.

  16. Reeve, Amy, Eve Simcox, and Doug Turnbull. 2014. “Ageing and Parkinson’s Disease: Why Is Advancing Age the Biggest Risk Factor?” Ageing Research Reviews 14 (100): 19–30. https://doi.org/10.1016/j.arr.2014.01.004.

  17. NHS. 2018. “Overview - Arthritis.” NHS. December 14, 2018. https://www.nhs.uk/conditions/arthritis/.

  18. “Age-Related Macular Degeneration | National Eye Institute.” 2021. Www.nei.nih.gov. June 22, 2021. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/age-related-macular-degeneration#:~:text=What%20is%20AMD%3F.

  19. DeGruttola, Arianna K., Daren Low, Atsushi Mizoguchi, and Emiko Mizoguchi. 2016. “Current Understanding of Dysbiosis in Disease in Human and Animal Models.” Inflammatory Bowel Diseases 22 (5): 1137–50. https://doi.org/10.1097/mib.0000000000000750.