How is essential fatty acid status usually evaluated?

• A. Triene:Tetraene ratio
• B. Serum cholesterol level
• C. Body mass index
• D. Glomerular filtration rate

Answer: (A)

Evaluating essential fatty acid status relies on the balance of specific fatty acids in circulating lipids, typically measured in plasma phospholipids or red blood cell membranes. When essential fatty acids are deficient, Mead acid (20:3 n-9) increases while arachidonic acid (20:4 n-6) decreases, causing the triene to tetraene ratio to rise. This ratio is a sensitive indicator of essential fatty acid deficiency and is commonly used in clinical nutrition, including monitoring patients on parenteral nutrition. Other measurements like serum cholesterol, body mass index, or glomerular filtration rate reflect different physiological aspects and do not directly indicate essential fatty acid stores, so they don’t reliably assess EFA status. A higher triene:tetraene ratio signals deficiency and prompts nutritional intervention.