Psychosom Med. 2007 Apr;69(3):217-24. Epub 2007 Mar 30.
[h=1]Depressive symptoms, omega-6
mega-3 fatty acids, and inflammation in older adults.[/h]
Kiecolt-Glaser JK,
Belury MA,
Porter K,
Beversdorf DQ,
Lemeshow S,
Glaser R.
[h=3]Source[/h]Department of Psychiatry, Ohio State University College of Medicine, 1670 Upham Drive, Columbus, OH 43210, USA.
[email protected]
[h=3]Abstract[/h][h=4]OBJECTIVE:[/h]To address how interactions between polyunsaturated fatty acid (PUFA) levels and depressive symptoms were related to proinflammatory cytokine synthesis. Depression and stress promote proinflammatory cytokine production. Dietary intakes of omega-3 (n-3) and omega-6 (n-6) PUFAs also influence inflammation; high n-6:n-3 ratios enhance proinflammatory cytokine production, although n-3 has anti-inflammatory properties.
[h=4]METHODS:[/h]Blood samples from 43 older adults (mean age = 66.67 years, SD = 10.09) provided data on PUFAs and tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-6 soluble receptor (sIL-6r). Depressive symptoms were assessed by the Center for Epidemiological Studies Depression Scale.
[h=4]RESULTS:[/h]Depressive symptoms and n-6:n-3 ratios worked together to enhance proinflammatory cytokines beyond the contribution provided by either variable alone, with substantial variance explained by their interaction: 13% for IL-6 and 31% for TNF-alpha, whereas full models accounted for 18% and 40%, respectively. Although predicted cytokine levels were consistent across n-6:n-3 ratios with low depressive symptoms, higher n-6:n-3 ratios were associated with progressively elevated TNF-alpha and IL-6 levels as depressive symptoms increased. Higher levels of sIL-6r were associated with higher n-6:n-3 ratios. Six individuals who met the criteria for major depressive disorder had higher n-6:n-3 ratios and TNF-alpha, IL-6, and sIL-6r levels than those who did not meet the criteria; excluding these six individuals reduced the variance explained by the depressive symptoms and n-6:n-3 ratio interaction.
[h=4]CONCLUSIONS:[/h]Diets with high n-6:n-3 PUFA ratios may enhance the risk for both depression and inflammatory diseases.