Key Findings:
Linoleic acid (LA) competes with ALA for enzymes required for conversion to their respective long-chain derivatives and for incorporation into the plasma membrane. This study showed that reducing dietary LA from 5% to < 2.5% energy decreased the production of n-6 derived pro-inflammatory mediators. The low LA diet increased the n-3 LCPUFA content of the plasma phospholipids. The data indicate that short-term reductions in dietary LA intake have the potential to improve n-3 LCPUFA status without a need to increase dietary n-3 LCPUFA intake. An increase in n-3 LCPUFA status would probably be greater by maintaining or increasing dietary ALA content and/or extending the intervention period beyond 4 weeks.
ABSTRACT:
This study aimed to determine the effect of reducing the dietary linoleic acid (LA) intake from less than 5% to < 2.5% energy on n-3 long chain PUFA (LCPUFA) status in humans. Thirty-six participants followed a < 2.5 % E LA diet for 4 weeks. Nutrient intakes were estimated from diet diaries and blood samples were collected for assessment of fatty acid composition in plasma and erythrocyte phospholipids. LA intakes were reduced from 4.5% E to 2% E during the low LA intervention while n-3 LCPUFA intakes were unchanged. LA and total n-6 PUFA content of plasma and erythrocyte phospholipids were significantly reduced after the low LA diet phase. The n-3 LCPUFA content of plasma phospholipids was significantly increased after the low LA diet compared to baseline. These data demonstrate that reducing LA intake for 4 weeks increases n-3 LCPUFA status in humans in the absence of increased n-3 LCPUFA intake. (Authors abstract)
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