What is the role of sebum in skin health?

Sebum plays a crucial role in maintaining skin health as it acts as both a moisturizer and a protective barrier. It is an oily substance produced by the sebaceous glands, and its primary function is to hydrate the skin. By forming a lipid barrier, sebum helps to prevent excessive water loss, thereby keeping the skin supple and resilient.

In addition to moisturizing, sebum also has protective properties. It helps to shield the skin from external environmental factors such as pollutants and pathogens, contributing to the skin's overall integrity. This barrier function is essential for maintaining the skin's natural balance and preventing dryness or irritation.

The other options do not accurately reflect the primary role of sebum. While the skin does require nutrients for repair, these come primarily from other sources rather than directly from sebum. Sebum does not play a role in reducing skin temperature; this is managed through perspiration and other physiological responses. Finally, rather than increasing sensitivity to the environment, sebum actually helps the skin resist harmful irritants, which underscores its protective role.