What factor may lead to a slower rate of nail growth?

Aging is a significant factor that can lead to a slower rate of nail growth. As individuals age, the body goes through various physiological changes that can affect the rate at which nails grow. Research indicates that nail growth typically decreases with age, primarily due to changes in the circulatory system and a reduction in metabolic rate. The nails may become thicker and grow at a slower pace, reflecting the overall slowing down of bodily functions that often accompanies aging.

In contrast, factors such as hydration levels can contribute positively to nail health and growth, while a high-protein diet generally provides the necessary nutrients to support keratin production, the main protein in nails. Regular manicures can help maintain the appearance of nails but do not directly impact the rate of nail growth itself.