AT A GLANCE:

• Aging affects every system in the body: from skin and hair to the brain, immune system, and organs.
• Many visible signs of aging reflect deeper cellular changes.
• While aging is inevitable, understanding how it unfolds helps guide strategies to support healthspan.
• New regenerative research focuses on preserving and restoring cellular function—not just treating symptoms.

According to the World Health Organization, the global population aged 60 and older will double by 2050. This demographic shift makes healthy aging one of the most important medical and societal challenges of our time.

Aging isn’t a single process. It’s the cumulative result of changes occurring across tissues, organs, and cells. While these changes show up differently for everyone, they follow recognizable biological patterns. Understanding these patterns is key to managing age-related decline and extending healthspan, not just lifespan. And the good news? Scientists are learning more about these shifts at a breakneck pace—and how to support them accordingly.

Below is a systems-based look at how aging affects the body, starting with the most visible changes… and moving inward.

Skin

Skin is the body’s largest organ. And it’s often the first place aging becomes visible: Over time, the skin’s ability to renew itself slows, structural support weakens, and repair takes longer.

As we age, fibroblasts—the cells responsible for producing collagen, elastin, and other structural components of the skin—become less active. When these “builder cells” slow down, the skin gradually loses firmness, elasticity, and resilience.

Common age-related skin changes include:

• Reduced oil (sebum) production, leading to dryness and itching
• Slower cell turnover, which can make skin appear dull or uneven
• Declining collagen and elastin, contributing to wrinkles and laxity
• Reduced hyaluronic acid, resulting in dehydration and thinning
• Slower wound healing and increased fragility

Many of these changes are also linked to an increase in senescent skin cells, or “zombie cells:” older cells that no longer divide or repair damage efficiently, but remain active and inflammatory.^1,2

Hair and Nails

Hair and nails are highly sensitive to changes in hormones, inflammation, and cellular health. Because hair follicles rely on active regeneration, for example, they are often early indicators of deeper cellular aging. (Gray hairs, anyone?)

Hair growth depends on healthy signaling between hair follicles and the surrounding scalp environment. With age, this communication becomes less efficient. Follicles may remain present, but they produce thinner hairs, grow more slowly, or spend longer periods in a resting phase.^3,4

Age-related changes in our nails and hair commonly include:

• Thinner strands and reduced density
• Increased time in the resting (telogen) phase of growth
• Graying due to a decline in melanocytes (pigment-producing cells)
• Slower hair and nail growth
• Brittle or thickened nails

Cardiovascular System

The cardiovascular system delivers oxygen and nutrients to every tissue in the body, so age-related changes can have profound effects.

Over time, blood vessels become stiffer and less elastic, making it harder for blood to flow efficiently. The heart also undergoes structural changes, including a gradual decline in specialized pacemaker cells that regulate heart rhythm.

Common age-related cardiovascular changes include:

• Stiffening of arteries and increased blood pressure
• Reduced production of nitric oxide (a molecule that helps blood vessels relax)
• Increased risk of clot formation
• Thickening of heart muscle tissue
• Slower production of new blood cells

These shifts affect endurance, recovery, and organ health throughout the body.⁵

Musculoskeletal System

The musculoskeletal system—our muscles, bones, joints, ligaments, and tendons—provides structure, movement, and stability.

With age, muscle cells shrink and decline in number, a process known as sarcopenia. At the same time, bones lose density, cartilage thins, and connective tissues become stiffer. (Your creaky knees might be an early sign.)

Common changes include:

• Loss of muscle mass and strength
• Reduced protein synthesis and slower muscle repair
• Decreased bone density and increased fracture risk
• Joint stiffness and reduced flexibility
• Slower recovery after physical stress

As these changes advance, they can impact mobility, balance, and overall independence.⁶

Brain and Nervous System

The brain is made up of billions of neurons supported by complex networks of other cells. Aging affects both the structure and function of these systems.

Over time, synaptic plasticity (the brain’s ability to form and adapt connections) declines. Blood flow to the brain decreases, and the production of key neurotransmitters slows.⁷

Age-related changes may include:

• Slower processing speed and memory recall
• Reduced blood flow to brain tissue
• Decline in neural stem cell activity (i.e. cells that help repair and maintain brain tissue)
• Increased vulnerability to inflammation

Some cognitive changes are expected. But all in all, brain aging is strongly influenced by cellular health and lifestyle factors.⁸

Vision and Hearing

Our eyes and ears rely on specialized cells that are particularly sensitive to aging.

With time, the lens of the eye becomes thicker and less flexible, making it harder to focus. The cells responsible for processing light and sound also regenerate more slowly.^9,10

Common changes include:

• Reduced tear production and dry eyes
• Increased risk of cataracts and macular degeneration
• Gradual hearing loss (presbycusis)
• Balance issues due to loss of sensory hair cells in the inner ear

Hormones

Hormones act as chemical messengers throughout the body, so age-related hormonal changes can impact the whole system.

As we age, production of several key hormones declines, including growth hormone and melatonin. Our reproductive hormones also shift significantly throughout our lives.¹¹

Examples include:

• Menopause and declining estrogen in women
• Reduced testosterone levels in men
• Changes in fertility, metabolism, bone density, and mood

By extension, these transitions can influence energy levels, tissue health, skin and hair, and sleep.

Immune System

The immune system protects the body from infection and supports healing. With age, it becomes less precise and slower to respond: a process known as immunosenescence.¹²

Key changes include:

• Reduced function of immune cells
• Slower wound healing
• Increased chronic inflammation
• Higher susceptibility to infection

This combination of weaker defense and heightened inflammation plays a major role in age-related disease.

Organ Health

Your organs don’t suddenly stop working as you age, but they do become a little less flexible and efficient over time. Think of it as having less backup when your body is under stress, illness, or fatigue.

As cellular repair slows, organs may take longer to bounce back from challenges and become more sensitive to lifestyle factors like diet, sleep, and hydration.

Some common age-related changes include:

• Kidneys: Filtering slows slightly, which can affect how your body balances fluids, electrolytes, and medications.¹³
• Liver: Detoxification and metabolism become less efficient, meaning alcohol, medications, and toxins may hit harder than they used to.¹⁴
• Pancreas: Cells involved in blood sugar regulation can become less responsive, increasing the risk of insulin resistance.¹⁵
• Lungs: Elasticity decreases, making breathing feel less effortless during exercise or illness.¹⁶

These shifts are subtle at first, but they help explain why recovery can feel slower with age—and why habits that support cellular health become increasingly important over time.

How To Support Healthy Aging

While aging affects every system differently, the underlying drivers are surprisingly consistent. Across skin, hair, muscle, brain, and organs, healthy aging depends on a few core biological principles: reducing chronic inflammation, supporting cellular repair, and preserving regenerative capacity.

And the habits that support this might be simpler than you think.

1. Protect your sleep. Deep, restorative sleep is when your body performs its most important repair work—clearing damaged cells, regulating hormones, and restoring immune balance. Poor sleep accelerates inflammation and cellular decline across nearly every system listed above.¹⁷
2. Move regularly to maintain cellular function. Physical activity supports circulation, mitochondrial health, muscle integrity, bone density, and brain health. Movement also helps the body clear the “zombie” cells that accumulate with age. (For what it’s worth, science shows that consistent low-impact exercise like walking and strength training should do the trick.)¹⁸
3. Eat to reduce inflammation and oxidative stress. You know the drill: Whole, nutrient-dense foods—particularly those rich in antioxidants, fiber, and healthy fats—help protect cells from damage that accelerates aging. After all, chronic inflammation and oxidative stress are two of the biggest contributors to age-related decline.¹⁹
4. Manage stress. Chronic stress raises cortisol levels, which can impair immune function, slow tissue repair, and accelerate cellular aging. Even short, consistent stress-regulation practices can make a meaningful difference over time. (Maybe a daily breathing exercise or two?)²⁰

Be proactive about aging. Many age-related changes begin decades before symptoms appear. That’s why modern longevity science is shifting toward early intervention—supporting the body’s repair systems before they’re overwhelmed.

This proactive mindset is where emerging strategies like regenerative medicine and stem cell preservation come into play.

Banking Your Most Resilient Cells

Nearly every effect of aging listed above can be traced back to changes at the cellular level. The process goes a little something like this: Stem cells lose regenerative power, repair signals weaken, and damaged cells accumulate over time.

As regenerative medicine continues to advance, many future therapies—whether for skin, hair, joints, or organs—will rely on a person’s own cells. It’s about harnessing our own biology to help signal regeneration, and effectively help our existing cells act younger.

This has led to growing interest in stem cell therapies and stem cell banking: preserving your healthiest, most regenerative cells earlier in life, before significant decline occurs.

By cryopreserving cells at ultra-low temperatures, biological aging is effectively paused. These cells can later be used as the foundation for personalized regenerative treatments as new medical and aesthetic applications emerge.

Acorn makes this process accessible through a non-invasive hair follicle collection method, allowing individuals to bank their stem cells without surgery or downtime. Right now, these stem cells are processed into a personalized secretome serum that can be used to enhance skincare treatments or for hair regeneration. 

But in the future? The applications abound. Rather than committing to a single treatment today, cell banking preserves optionality—keeping your body’s most regenerative resources available for wherever longevity science takes us.

FAQ

Q: What are the most common effects of aging on the body?
A: Aging affects nearly every system, including skin, hair, muscles, brain, immune function, and organs. These changes are driven by slower cellular repair, increased inflammation, and reduced regenerative capacity over time.

Q: When does aging actually begin?
A: Cellular aging can begin as early as your late 20s or early 30s—long before visible signs appear. Many effects accumulate quietly for decades before symptoms surface.

Q: Why do skin and hair tend to show aging first?
A: Skin and hair rely heavily on fast cell turnover and regenerative signaling. As those processes slow, changes like wrinkles, thinning hair, and slower healing become more noticeable.

Q: What is cellular senescence?
A: Cellular senescence occurs when cells stop dividing but don’t die. These cells release inflammatory signals that can disrupt surrounding tissue and accelerate aging throughout the body.

Further Reading:

1. Shin, S. H., Lee, Y. H., Rho, N. K., & Park, K. Y. (2023). Skin aging from mechanisms to interventions: focusing on dermal aging. Frontiers in physiology, 14, 1195272. https://doi.org/10.3389/fphys.2023.1195272 
2. Hou, X., Wei, Z., Zouboulis, C. C., & Ju, Q. (2022). Aging in the sebaceous gland. Frontiers in cell and developmental biology, 10, 909694. https://doi.org/10.3389/fcell.2022.909694 
3. Liang, A., Fang, Y., Ye, L., Meng, J., Wang, X., Chen, J., & Xu, X. (2023). Signaling pathways in hair aging. Frontiers in cell and developmental biology, 11, 1278278. https://doi.org/10.3389/fcell.2023.1278278 
4. Rao, S., Banerjee, S., Ghosh, S. K., Gangopadhyay, D. N., Jana, S., & Mridha, K. (2010). Nail changes and nail disorders in the elderly. Indian journal of dermatology, 55(3), 301–304. https://doi.org/10.4103/0019-5154.70695 (Retraction published Indian J Dermatol. 2012 Jan;57(1):I.) 
5. Vakka, A., Warren, J. S., & Drosatos, K. (2023). Cardiovascular aging: from cellular and molecular changes to therapeutic interventions. The journal of cardiovascular aging, 3(3), 23. https://doi.org/10.20517/jca.2023.09 
6. Walston J. D. (2012). Sarcopenia in older adults. Current opinion in rheumatology, 24(6), 623–627. https://doi.org/10.1097/BOR.0b013e328358d59b 
7. Appelbaum, L. G., Shenasa, M. A., Stolz, L., & Daskalakis, Z. (2023). Synaptic plasticity and mental health: methods, challenges and opportunities. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 48(1), 113–120. https://doi.org/10.1038/s41386-022-01370-w
8. Potashkin, J. A., Vidyadhara, D. J., & Hunsberger, H. C. (2025). The Impact of Lifestyle on Brain Health. American journal of lifestyle medicine, 15598276251411888. Advance online publication. https://doi.org/10.1177/15598276251411888
9. Singh P, Zeppieri M, Tripathy K. Presbyopia. [Updated 2025 Jun 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560568/
10. Hughes, S. E., Brenner, C. R., Pandian, A. T., Ross, E. J., Nieman, C. L., McKee, M. M., McCaslin, D. L., Tunkel, D. E., Manojlovich, M., Wallhagen, M. I., & Brenner, M. J. (2025). Age-Related Hearing Loss: Evidence-Based Strategies for Early Detection and Management. ORL-head and neck nursing : official journal of the Society of Otorhinolaryngology and Head-Neck Nurses, 43(2), 26–39.
11. Biagetti, B., & Puig-Domingo, M. (2023). Age-Related Hormones Changes and Its Impact on Health Status and Lifespan. Aging and disease, 14(3), 605–620. https://doi.org/10.14336/AD.2022.1109
12. Fu, Y., Wang, B., Alu, A. et al. Immunosenescence: signaling pathways, diseases and therapeutic targets. Sig Transduct Target Ther 10, 250 (2025). https://doi.org/10.1038/s41392-025-02371-z
13.  Fang, Y., Gong, A. Y., Haller, S. T., Dworkin, L. D., Liu, Z., & Gong, R. (2020). The ageing kidney: Molecular mechanisms and clinical implications. Ageing research reviews, 63, 101151. https://doi.org/10.1016/j.arr.2020.101151
14. Williams, S. N., & Ding, W. X. (2025). The impact of aging on liver health and the development of liver diseases. Hepatology communications, 9(10), e0808. https://doi.org/10.1097/HC9.0000000000000808
15. De Tata V. (2014). Age-related impairment of pancreatic Beta-cell function: pathophysiological and cellular mechanisms. Frontiers in endocrinology, 5, 138. https://doi.org/10.3389/fendo.2014.00138
16. Sharma, G., & Goodwin, J. (2006). Effect of aging on respiratory system physiology and immunology. Clinical interventions in aging, 1(3), 253–260. https://doi.org/10.2147/ciia.2006.1.3.253
17. Miao, Y., Wang, J., Li, X., Guo, J., Ekblom, M. M., Sindi, S., Zhang, Q., & Dove, A. (2025). Poor sleep health is associated with older brain age: the role of systemic inflammation. EBioMedicine, 120, 105941. https://doi.org/10.1016/j.ebiom.2025.105941
18. Chan, M. L. T., & Yu, D. S. F. (2022). The effects of low-impact moderate-intensity stepping exercise on fatigue and other functional outcomes in older adults with multimorbidity: A randomized controlled trial. Archives of gerontology and geriatrics, 98, 104577. https://doi.org/10.1016/j.archger.2021.104577
19.  Tessier, AJ., Wang, F., Korat, A.A. et al. Optimal dietary patterns for healthy aging. Nat Med 31, 1644–1652 (2025). https://doi.org/10.1038/s41591-025-03570-5 
20.  Yegorov, Y. E., Poznyak, A. V., Nikiforov, N. G., Sobenin, I. A., & Orekhov, A. N. (2020). The Link between Chronic Stress and Accelerated Aging. Biomedicines, 8(7), 198. https://doi.org/10.3390/biomedicines8070198

—

This article has been medically reviewed by:

Amatullah Fatehi | MSc, Director of Product Development and Innovation

Amatullah Fatehi is a regenerative medicine scientist with expertise in cell physiology and stem cell biology. She led the development of Acorn’s hair-follicle-derived secretome product and oversees key research and product innovation initiatives.