Which of the following is a major risk factor for osteoarthritis?

Aging is indeed a major risk factor for osteoarthritis, as the condition primarily affects older adults. Over time, the cartilage that cushions the joints can wear down, leading to pain, stiffness, and inflammation. The natural aging process brings about changes in the joints, including decreased cartilage elasticity and increased bone-to-bone contact, which can exacerbate the degradation of joint surfaces.

While obesity is also a significant risk factor due to the additional stress it places on weight-bearing joints, it may not be considered a primary or universal factor for everyone developing osteoarthritis, as not all individuals with obesity will have osteoarthritis, and some may have it without being overweight. High protein diets and excessive exercise are not directly linked to the onset of osteoarthritis, though they can impact overall joint health in different ways. Therefore, the primary connection to aging illustrates the inevitable age-related changes that contribute to the development of osteoarthritis.