IMPORTANCE OF DIETARY GAMMA-LINOLENIC ACID IN HUMAN HEALTH AND NUTRITION

Considerable debate remains regarding the distinct biological activiti es of individual polyunsaturated fatty acids (PUFA). One of the most i nteresting yet controversial dietary approaches has been the possible prophylactic role of dietary gamma-linolenic acid (GLA) in treating va rious chronic disease states. This strategy is based on the ability of diet to modify cellular lipid composition and eicosanoid (cyclooxygen ase and lipoxygenase) biosynthesis. Recent studies demonstrate that di etary GLA increases the content of its elongase product, dihomo-gamma- linolenic acid (DGLA), within cell membranes without concomitant chang es in arachidonic acid (AA). Subsequently, upon stimulation, DGLA can be converted by inflammatory cells to 15-(S)-hydroxy-8,11,13-eicosatri enoic acid and prostaglandin E-1. This is noteworthy because these com pounds possess both anti-inflammatory and anti-protiferative propertie s. Although an optimal feeding regimen to maximize the potential benef its of dietary GLA has not yet been determined, it is the purpose of t his review to summarize the most recent research that has focused on o bjectively and reproducibly determining the mechanism(s) by which GLA may ameliorate health problems.