An international team of researchers has found that human evolution may have left people more vulnerable to joint disease, Israel’s Weizmann Institute of Science says.
In their new study, published in the journal Nature, the researchers examined genetic differences between humans and other great apes, including chimpanzees and gorillas.
The researchers found that humans produce significantly lower levels of glycosaminoglycans, or GAGs, in their cartilage. GAGs are sugar molecules that attract water and help cartilage absorb shocks and cushion joints.
The team found that human cartilage contains about one-third as much GAG material as the cartilage of chimpanzees, gorillas, orangutans and bonobos.
The finding may help explain why osteoarthritis and other joint disorders are common in humans but rare in other great apes, even those that reach old age. Osteoarthritis affects hundreds of millions of people worldwide and can cause pain, stiffness, and disability.
The researchers suggested that the evolutionary change may have contributed to other human traits, including lighter bones and a more flexible brain.
They concluded that the findings could help scientists better understand joint diseases and potentially identify new approaches to their prevention and treatment. ■