Comparable reductions in hyperpnoea-induced bronchoconstriction and markers of airway inflammation after supplementation with 6·2 and 3·1 g/d of long-chainn-3 PUFA in adults with asthma

Abstract

Although high dose n-3 PUFA supplementation reduces exercise- and hyperpnoea-induced bronchoconstriction (EIB/HIB), there are concurrent issues with cost, compliance and gastrointestinal discomfort. It is thus pertinent to establish the efficacy of lower n-3 PUFA doses. Eight male adults with asthma and HIB and eight controls without asthma were randomly supplemented with two n-3 PUFA doses (6·2 g/d (3·7 g EPA and 2·5 g DHA) and 3·1 g/d (1·8 g EPA and 1·3 g DHA)) and a placebo, each for 21 d followed by 14 d washout. A eucapnic voluntary hyperpnoea (EVH) challenge was performed before and after treatments. Outcome measures remained unchanged in the control group. In the HIB group, the peak fall in forced expiratory volume in 1 s (FEV1) after EVH at day 0 (-1005 (sd 520) ml, -30 (sd 18) %) was unchanged after placebo. The peak fall in FEV1 was similarly reduced from day 0 to day 21 of 6·2 g/d n-3 PUFA (-1000 (sd 460) ml, -29 (sd 17) % v. -690 (sd 460) ml, -20 (sd 15) %) and 3·1 g/d n-3 PUFA (-970 (sd 480) ml, -28 (sd 18) % v. -700 (sd 420) ml, -21 (sd 15) %) (P<0·001). Baseline fraction of exhaled nitric oxide was reduced by 24 % (P=0·020) and 31 % (P=0·018) after 6·2 and 3·1 g/d n-3 PUFA, respectively. Peak increases in 9α, 11β PGF2 after EVH were reduced by 65 % (P=0·009) and 56 % (P=0·041) after 6·2 and 3·1 g/d n-3 PUFA, respectively. In conclusion, 3·1 g/d n-3 PUFA supplementation attenuated HIB and markers of airway inflammation to a similar extent as a higher dose. Lower doses of n-3 PUFA thus represent a potentially beneficial adjunct treatment for adults with asthma and EIB.

EAACI position paper: Influence of dietary fatty acids on asthma, food allergy, and atopic dermatitis

“…In adults with exercise‐induced bronchoconstriction, multiple studies examining supplementation with n ‐3 LC‐PUFAs showed attenuation of hyperpnoea‐induced bronchoconstriction and/or improved asthma symptoms . However, one study showed no effect in this asthma group .…”

The Influence of Dietary Fatty Acids on Immune Responses

“…Several more recent interventional clinical trials investigated the effects of PUFA supplementation on development and symptoms of asthma. Higher proportions of n-3 PUFAs in the diet are linked with a decreased risk and improved asthma control in both children [201,[220][221][222][223] and adults [47,202,[224][225][226][227][228][229][230][231][232][233][234].…”

“…In adulthood, benefits are demonstrated as a decreased prevalence of asthma symptoms, improved asthma control, decreased levels of fractional exhaled nitric oxide (FeNO), blood eosinophilia and improved lung function [47,202,[224][225][226][227][228][229][230][231][232][233][234]. Additionally, n-3 PUFAs have beneficial effects by reducing airway hyperresponsiveness and severity of exercise-induced bronchoconstriction [233].…”

“…↓ Risk of asthma, rhinitis and aeroallergen sensitization [200,204,220,221] ↓ Asthma symptoms scores and ↓ responsiveness to acetylcholine [222] Improvement in pulmonary functions and ↓ use of short-acting inhaled bronchodilators and inhaled corticosteroids [290] ↑ Prevalence of wheeze [248] Adulthood ↓ Prevalence of asthma symptoms, airway hyperresponsiveness and ↑ asthma control and lung function [47,202,206,207,224,[226][227][228]230,233] ↓ Exhaled nitric oxide, ↓ serum eosinophils and ↑ FEV1 [225,229] ↓ Bronchodilator use, ↓ exhale nitric oxide and ↓ severity of exercise-induced bronchoconstriction [228,[231][232][233] Allergic Rhinitis Infancy and childhood ↓ Risk of rhinitis development [251,[254][255][256] Adulthood ↓ Prevalence [257,258] Atopic Dermatitis Pregnancy and lactation ↓ Incidence and intensity in the offspring [259,260]…”

Oil supplementation with a special combination of n-3 and n-6 long-chain polyunsaturated fatty acids does not protect for exercise induced asthma. A double-blind placebo-controlled trial.

“…Especially n-3 long-chain PUFA (n-3 LCPUFA) exert well known anti-inflammatory effects, which are in part associated with a change in cell membrane composition (8,9). In line with this concept many studies demonstrated that supplementation of n-3 LCPUFA have beneficial effects on EIA (10)(11)(12)(13)(14)(15). In contrast, there are many studies which failed to show clinical improvement of EIA by n-3 LCPUFA supplementation (16)(17)(18)(19)(20)(21)(22).…”