Have you noticed that someone gets shorter as the years go by? In fact, as they age, some people may start to slouch forward and become several inches shorter.
Shrinkage or erosion?
An article published in Live Science revealed that what happens is a combination of “wear and tear” of human bones, thinning of cartilage and shrinking of muscles. But the rates at which these processes occur vary depending on genetics, physical nutrition and activity levels throughout a person’s life.
According to the article, this shrinkage begins at the age of thirty and accelerates over time, as bone deterioration causes a decrease in height after the bones begin to decompose after the age of forty to fifty.
“We all age differently biologically,” said Marian Hannan, an epidemiologist at Harvard Medical School who researches aging. “That’s why people always get shorter as they get older.”
A study by the National Institute on Aging, which followed 2,084 men and women for 35 years, found that they began losing height around age 30, and that the shrinkage accelerated over time.
The study, which included people aged 17 to 94, found that men, on average, lost 1.2 inches (3 cm) and women lost 2 inches (5 cm) between the ages of 30 and 70. By age 80, men had lost 2 inches (5 cm) and women 3 inches (8 cm), largely because human bones begin to break down as we age.
If we go back to the beginning of human life, we find that bones are formed in the eighth week of pregnancy, and they continue to grow until people reach their mid-twenties. Bones also become denser when they have to support a higher muscle mass. As muscles grow, they produce collagen fibers, which stretch and increase local blood flow, which in turn stimulates bone growth.
While bone growth stops at age 25 to 30, at age 40 to 50, we begin to gradually lose bone mass, as old bone begins to break down faster than the body can make new bone.
“Bones are like a matrix that connects together,” adds Marian Hannan. The bone matrix is made up primarily of the protein collagen and the mineral hydroxyapatite. When people lose bone mass, “these bridge-like structures weaken, and small, tiny loads added to them can cause microfractures, causing the tiny, tiny bone bridges to collapse.”
Small-scale bone damage can also lead to osteoporosis, which makes bones thin, brittle and weak. Osteoporosis can in turn cause larger bone fractures, which are common in the spine, hips and arms, and can also lead to loss of height.
Losing height changes body shape.
Some scientists say that loss of height also occurs due to poor posture during daily routine. A sharp forward curvature or bending of the spine, also known as hyperkyphosis, can lead to a permanent rounding of the upper back, which results in the removal of a few inches of height.
In addition, muscles also play an important role in age-related shrinkage. Older people can experience muscle wasting, a condition known as osteoporosis, which is associated with weaker bone structure and an increased likelihood of bone loss. A lack of muscle support around the trunk will impair a person’s ability to stand upright.
Unlike osteoporosis, which can be treated with medications such as alendronate, there is no “magic pill” for muscle loss, but exercise and a better diet help.
Losing height has serious health consequences, and while the cause remains unclear, multiple studies have shown links between height loss and serious health conditions, such as respiratory problems and cardiovascular disease.