Systemic inflammation in morbidly obese subjects: response to oral supplementation with alpha-linolenic acid.

Background: Morbidly obese patients frequently display asymptomatic chronic activation of acute phase response, with potentially adverse metabolic and cardiovascular consequences. Nutritional preparations to improve this phenomenon have rarely been administered. Aiming to investigate the supplementation of flaxseed flour, a source of omega-3 fatty acids, a prospective randomized double-blind cross-over study was designed.
Methods: Outpatient obese subjects (n=41) were clinically and biochemically screened, and results for 24 randomized subjects are shown. Age was 40.8 +/- 11.6 years (83.3% females) and body mass index (BMI) was 47.1 +/- 7.2 kg/m2. Flaxseed flour (Farinha de Linhaca Dourada LinoLive, Cisbra, Brazil) in the amount of 30 g/day (5 g of alpha-linolenic acid - omega-3) and an equal mass of placebo (manioc flour) were administered for 2 weeks each. Variables included general biochemical investigation, white blood cell count (WBC), C-reactive protein (CRP), serum amyloid A (SAA) and fibronectin.
Results: No intolerance was registered. Body weight and general biochemical indices remained stable. Initial CRP and SAA were elevated (13.7 +/- 9.9 and 17.4 +/- 8.0 ). WBC (8100 +/- 2100/mm3) and fibronectin (463.2 +/- 61.3 mg/dL) were acceptable but in the upper normal range. Corresponding findings after supplementation of flaxseed were 10.6 +/- 6.2 mg/L, 14.3 +/- 9.2 mg/L, 7300 +/- 1800/mm3 and 412.8 +/- 38.6 respectively (P<0.05). No change during the control period regarding baseline occurred when placebo was randomized to be given first; however, when it followed omega-3 supplementation, CRP and SAA recovered, whereas WBC and fibronection remained depressed during those 2 weeks (7500 +/- 2100/mm3 and 393.2 +/- 75.8 mg/dL, P<0.05).
Conclusions: 1) Various inflammatory markers were elevated in the studied population, although not necessarily exceeding the normal range; 2) Significant reduction could be demonstrated; 3) Some persistent effects of flaxseed supplement 2 weeks after discontinuation were observed.