We do tend to get shorter as we age due to several factors affecting the structure of our spine and other aspects of our skeletal system.

Here are the primary reasons:

1. Disc Degeneration: The intervertebral discs, which act as cushions between the vertebrae, begin to lose moisture and elasticity over time. This degeneration causes the discs to thin and compress, reducing the overall height of the spine.
2. Vertebral Changes: The vertebrae themselves can lose density and strength, a condition often due to osteoporosis. This can lead to compression fractures in the vertebrae, which also decreases spine height.
3. Postural Changes: Changes in posture and gait, often due to muscular weaknesses and other changes in the musculoskeletal system, can lead to a more stooped posture, which reduces height.
4. Joint Cartilage Wear: The cartilage in our joints, including the knees and hips, can wear down with age, leading to joint changes that may also affect overall height.

These changes are typically gradual and can be influenced by lifestyle factors such as diet, exercise, and overall health maintenance. Addressing bone health through adequate calcium and vitamin D intake, engaging in regular weight-bearing exercise, and preventing falls can help mitigate some of these age-related height losses. 

What is the average height loss we experience in our senior years?

This varies, but generally, adults can expect to shrink by about 1 to 3 inches as we move from middle age into our senior years. The rate and amount of height loss can depend on several factors, including:

• Gender: Women tend to lose slightly more height than men, partly due to the higher incidence of osteoporosis in women.
• Bone Density: Individuals with lower bone density or osteoporosis are more susceptible to vertebral compression fractures, which can significantly contribute to height loss.
• Genetic Factors: Genetic predispositions to conditions like osteoporosis can also play a significant role.

Height loss typically accelerates with age and is most noticeable after the age of 70. Again, regular medical check-ups, maintaining a healthy lifestyle, and addressing bone health can help manage and potentially reduce the extent of height loss in later life.