Polyunsaturated fatty acids: biochemical, nutritional and epigenetic properties.
Dietary polyunsaturated fatty acids (PUFA) have effects on diverse physiological processes impacting normal health and chronic diseases, such as the regulation of plasma lipid levels, cardiovascular and immune function, insulin action and neuronal development and visual function. Ingestion of PUFA will lead to their distribution to virtually every cell in the body with effects on membrane composition and function, eicosanoid synthesis, cellular signaling and regulation of gene expression. Cell specific lipid metabolism, as well as the expression of fatty acid-regulated transcription factors, likely play an important role in determining how cells respond to changes in PUFA composition. This review will focus on recent advances on the essentiality of these molecules and on their interplay in cell physiology, leading to new perspective in different therapeutic fields.
This article reviewed, among many others, the study from EPA + GLA Increases Bone Density in Elderly Women:
In a single-blind, randomized study, Kruger et al.  tested the interactions between calcium and DGLA + EPA in osteoporotic or osteopenic women. All of the women were living in the same institution for the elderly and fed the same low-calcium, non-vitamin D enriched foods, and had similar amounts of sunlight. Subjects were randomly assigned to DGLA + EPA or coconut oil (placebo group); in addition, all received 600 mg/day of calcium. Markers of bone formation/degradation and bone mineral density (BMD) were measured at baseline, 6, 12 and 18 months. At 18 months, osteocalcin and deoxypyridinoline levels fell significantly in both groups, indicating a decrease in bone turnover, whereas bone specific ALP rose indicating beneficial effects of calcium given to all the patients. Lumbar and femoral BMD, in contrast, showed different results in the two groups. Over the first 18 months, lumbar spine density remained the same in the treatment group, but decreased 3.2% in the placebo group. Femoral bone density increased 1.3% in the treatment group, but decreased 2.1% in the placebo group. During the second period of 18 months with all patients now on active treatment, lumbar spine density increased 3.1% in patients who remained on active treatment, and 2.3% in patients who switched from placebo to active treatment; femoral BMD in the latter group showed an increase of 4.7%.