Fiber, particularly soluble fiber found in foods like oats, beans, fruits, and vegetables, assists in lowering cholesterol levels. It does this by binding with cholesterol in the digestive system and preventing its absorption into the bloodstream. Consequently, this helps reduce the amount of cholesterol that makes its way into circulation. Soluble fiber can also reduce low-density lipoprotein (LDL), commonly known as "bad" cholesterol, by interfering with the absorption of dietary fats and promoting the excretion of bile acids, which are made from cholesterol, thus necessitating the use of more bodily cholesterol to produce more bile. Regular consumption of high-fiber foods is a recommended strategy for managing cholesterol levels, alongside other healthy habits like maintaining a balanced diet and engaging in regular exercise.

Cellulose is a crucial structural component found in the cell walls of plants and algae. It is a complex carbohydrate, or polysaccharide, consisting of glucose units linked together to form long chains. These cellulose fibers give rigidity and strength to the cell wall, allowing plants to maintain their shape and resist external pressures. In the context of the cell, the cell wall acts as an external skeleton. While animal cells lack cell walls, in plants, algae, and some bacteria, the cell wall with cellulose is essential for protection, structure, and support, making it distinct from the cell membrane, which all cells have. The cellulose in the cell walls is also significant for humans and other animals that cannot digest it themselves, as it acts as dietary fiber, aiding in digestion.

Polypropylene plastic, a thermoplastic polymer widely used in packaging, textiles, and various household items, is generally considered safe and is not classified as carcinogenic by major health organizations such as the International Agency for Research on Cancer (IARC) or the U.S. National Toxicology Program. Its construction involves a high molecular weight and non-reactivity, which contributes to its stability and lower risk profile compared to other plastics. However, like with any plastic product, potential health risks may arise from additives used in manufacturing or from decomposition products released if the plastic is burned or heated to high temperatures. Ensuring that polypropylene products are used as intended and avoiding exposure to high heat can minimize potential risks.