Why are essential fatty acids defined as essential for humans?

Why are essential fatty acids defined as essential for humans?

• A. Because they cannot be synthesized by humans and must be obtained through diet
• B. Because they are the only energy sources for brain
• C. Because they are the primary components of DNA
• D. Because they are routinely stored in bone

Answer: (A)

Essential fatty acids are defined as essential because the body cannot synthesize them in adequate amounts, so they must come from the diet to support normal structure and function. Humans rely on two classic essential fatty acids—linoleic acid (omega-6) and alpha-linolenic acid (omega-3)—because we lack the desaturase enzymes that insert double bonds beyond the ninth carbon. Without these fatty acids, cell membranes lose proper fluidity and function, and the body’s production of important signaling molecules (eicosanoids) is impaired. They’re also important for growth, development, and vision. The brain’s main energy comes from glucose (and ketones when fasting), not fatty acids; DNA is made of nucleotides, not fatty acids; and bones store minerals, not routine fatty acids.

Essential fatty acids are defined as essential because the body cannot synthesize them in adequate amounts, so they must come from the diet to support normal structure and function. Humans rely on two classic essential fatty acids—linoleic acid (omega-6) and alpha-linolenic acid (omega-3)—because we lack the desaturase enzymes that insert double bonds beyond the ninth carbon. Without these fatty acids, cell membranes lose proper fluidity and function, and the body’s production of important signaling molecules (eicosanoids) is impaired. They’re also important for growth, development, and vision. The brain’s main energy comes from glucose (and ketones when fasting), not fatty acids; DNA is made of nucleotides, not fatty acids; and bones store minerals, not routine fatty acids.