[Significance of fatty acid composition in plasma and in food for cellular immune function in elderly men]

The relation between fatty acid composition in plasma and natural killer (NK) cell activity and the relation between fatty acid composition of diet and NK cell activity was evaluated in healthy elderly men. The correlations between basal NK activity and the fraction of plasma fatty acids consisting of total polyunsaturated fatty acids (PUFA), total n-6 fatty acids and linoleic acid were r = -0.68, p = 0.006, r = 0.62, p = 0.014 and r = 0.52, p = 0.048, respectively. Significant negative correlations were also found between alpha-interferon stimulated NK cell activity and the three groups of fatty acids and between interleukin-2 stimulated NK cell activity and PUFA. Likewise, negative correlations between grammes of PUFA in diet, determined from two four-day registration-periods, and basal NK and alpha-interferon stimulated NK cell activity were found. No significant negative correlation between percentage intake of n-3 fatty acids and NK cell activity was found. It is concluded that the type of dietary fatty acids influence NK cell activity in elderly men. A high intake of n-6 polyunsaturated fatty acids may be detrimental to cellular immune defence mechanisms in the elderly.