What are carotenoids primarily known for protecting?

Carotenoids are primarily recognized for their antioxidant properties, which play a crucial role in protecting cells from damage caused by free radicals. Free radicals are unstable molecules that can lead to oxidative stress, contributing to various chronic diseases and aging processes. By neutralizing these free radicals, carotenoids help to safeguard cellular structures, including cell membranes and DNA, thus maintaining overall cellular health.

The other options do not align with the primary function of carotenoids. Their role in enhancing appetite, improving sleep quality, or facilitating better digestion is not directly tied to their biological activity. While some vitamins and dietary components may influence those areas, carotenoids are specifically noted for their protective and antioxidant roles within the body.