Which of the following is considered an essential fatty acid?

Appeared in: BTSC Staff Nurse 30July-2025

Explanation

Linoleic acid is classified as an essential fatty acid because the human body cannot synthesize it.
It is a polyunsaturated omega-6 fatty acid, meaning it has multiple double bonds with the first one located at the sixth carbon from the omega end.
Humans lack the desaturase enzymes needed to create double bonds beyond the 9th carbon position, making dietary intake of omega-6 and omega-3 fatty acids necessary.
Linoleic acid is a precursor for arachidonic acid, which is involved in producing eicosanoids that regulate inflammation and other cellular processes.

Option A: Oleic acid is a monounsaturated omega-9 fatty acid. The body can synthesize it, so it is considered non-essential.
Option B: Stearic acid is a saturated fatty acid. The body can synthesize saturated fats, so it is non-essential.
Option C: Palmitic acid is a saturated fatty acid. It is the most common fatty acid in animals and can be synthesized by the body, making it non-essential.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Essential Fatty Acids in Nutrition as background academic context rather than a clinical decision trigger.
Nurses must assess for signs of EFA deficiency, such as dry, scaly skin (phrynoderma), alopecia, and poor wound healing, especially in at-risk patients.
Patients receiving long-term Total Parenteral Nutrition (TPN) without lipid emulsions are at high risk for EFA deficiency.
Dietary counseling for patients should include information on good sources of essential fatty acids, like certain vegetable oils, nuts, seeds, and fish, to promote cardiovascular and overall health.

How to Approach the Question

First, identify the key term in the question: 'essential fatty acid'.
Recall the definition of an essential nutrient: something the body needs but cannot produce on its own, so it must be obtained from the diet.
Mentally list the two main essential fatty acids: linoleic acid (an omega-6) and alpha-linolenic acid (an omega-3).
Scan the given options to see if either of these essential fatty acids is listed.
Eliminate the other options by identifying them as non-essential (saturated or monounsaturated) fatty acids that the body can synthesize.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) p. 145-147

E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) p. 20-22

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 1 (pp 26-370 of 370) p. 236-238

Practise the full BTSC Staff Nurse 30July-2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.