Which of the following is NOT an antioxidant?

Cholesterol is not considered an antioxidant, which is why it's the correct choice. Antioxidants are substances that help neutralize free radicals in the body, thereby preventing oxidative stress and potential damage to cells. Curcumin, flavonoids, and alpha-lipoic acid all possess antioxidant properties.

Curcumin, found in turmeric, has been shown to activate antioxidant genes and reduce inflammation. Flavonoids, which are abundant in fruits and vegetables, are known for their ability to scavenge free radicals and support overall health. Alpha-lipoic acid is a powerful antioxidant that is both water and fat-soluble, allowing it to work throughout the body and regenerate other antioxidants.

In contrast, cholesterol is a lipid that plays a key role in cell membrane structure and functions but does not have the properties associated with antioxidant activity. It is important to differentiate between these substances since understanding their roles in health is crucial for esthetics and overall wellness.