What happens in our bodies as we age?

Everyone knows the classic, visible signs of ageing. Older people need reading glasses, have grey hair and stiff joints. But already from the age of 20, many classic signs of ageing can become apparent on the human body.

Wrinkles appear as the skin loses elasticity due to the loss of collagen, elastin and hyaluronic acid. Endurance decreases as the production of alveoli in the lungs decreases, resulting in less tidal volume and less oxygen in the blood. The number of hair cells in the cochlea decreases, making it harder to hear high-pitched sounds. By the age of 25, fertility in women and testosterone levels in men start to decline [Belsky et al. 2015].

A little later, sperm density also decreases in men. From the age of 30, the elasticity of the cartilage slowly decreases and certain movements become more difficult. The intervertebral discs also become thinner. From the age of 35, the first grey hairs begin to appear as melanin production slows down and later stops altogether. Around the age of 40, the lens of the eye thickens and loses its flexibility (presbyopia) and reading becomes more difficult.

From the age of 55, muscle loss increases and the body changes its ratio of muscle to fat. The ageing process begins to show in the calcification of the blood vessels, causing blood pressure to rise. Organs such as the kidneys and liver begin to function less efficiently, which means that the body’s detoxification process slows down. As we age, neurodegenerative diseases such as dementia (e.g. Alzheimer's), Parkinson's, cardiovascular disease and cancer become more common, to name just a few of the most common age-related diseases [Bektas et al. 2018, Lakatta et al. 2003, Partridge et al. 2018].

More FAQs on ageing

References: 

• Belsky DW, Caspi A, Houts R, Cohen HJ, Corcoran DL, Danese A, Harrington H, Israel S, Levine ME, Schaefer JD, Sugden K, Williams B, Yashin AI, Poulton R, Moffitt TE (2015) Quantification of biological aging in young adults. Proc Natl Acad Sci U S A 112(30)
• Bektas A, Schurman SH, Sen R, Ferrucci L (2018) Aging, inflammation and the environment. Exp Gerontol 105(10-18).
• Lakatta EG, Levy D (2003) Arterial and cardiac aging: major shareholders in cardiovascular disease enterprises: Part II: the aging heart in health: links to heart disease. Circulation 107(2):346-354.
• Partridge L, Deelen J, Slagboom PE (2018) Facing up to the global challenges of ageing. Nature 561(7721):45-56.