Latest Research on Asthma and the Influence of Nutritional Supplements

TITLE: Maternal antioxidant intake in pregnancy and wheezing illnesses in children at 2 y of age. Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA

AUTHORS: Litonjua AA, Rifas-Shiman SL, Ly NP, Tantisira KG, Rich-Edwards JW, Camargo CA Jr, Weiss ST, Gillman MW, Gold DR.

JOURNAL: Am J Clin Nutr. 2006, Oct;84(4):903-11

This study looked at whether low intakes of dietary antioxidants may contribute to increases in asthma and allergy in 1290 mother-child pairs in an ongoing cohort study. Maternal dietary and supplement intakes were assessed by using a validated food-frequency questionnaire administered in the first and second trimesters. Antioxidant nutrient intakes were calculated, and the mean for each nutrient was considered to be the exposure during pregnancy. The outcomes of interest were any wheezing by the child during either the first or second year of life, recurrent wheezing in both years, and eczema in either the first or second year. Those with the highest total intakes of vitamin E and zinc had less wheezing at 2 y of Similar results were obtained for recurrent wheezing at 2 y of age with vitamin E and zinc.  CONCLUSION: “Our results suggest that higher maternal total intakes of antioxidants during pregnancy may decrease the risks for wheezing illnesses in early childhood.”

TITLE: Effect of daily cod liver oil and a multivitamin-mineral with selenium on upper respiratory tract pediatric visits by young, inner-city, Latino children: Randomized pediatric sites.

AUTHORS: Linday LA, Shindledecker RD, Tapia-Mendoza J, Dolitsky JN

JOURNAL: Annals of Otology, Rhinology & Laryngology 2004, Volume 113, Number 11 (November), pages 891-901

Linday et al studied the effect of daily supplementation with lemon-flavored cod liver oil and a children's multivitamin-mineral supplement containing selenium on the number of pediatric visits by young, inner-city, Latino children from late autumn of 2002 through early spring of 2003. Two private pediatric offices with similar demographics, located 1.1 miles apart in upper Manhattan, New York City, were randomized to a supplementation site and a medical records control site. Ninety-four children (47 at each site), 6 months to 5 years of age, were enrolled. The mean age of the supplementation group was 2.03 years; that of the control group was 2.08 years. Children > or = 1 year of age in the supplementation group received 1 teaspoon of lemon-flavored cod liver oil per day and one half-tablet of a children's multivitamin-mineral; the starting dose was halved for children < 1 year of age. The supplements were given from enrollment through May 1, 2003. The primary outcome measure was the number of upper respiratory tract pediatric visits during the follow-up/supplementation period. The supplementation group had a statistically significant decrease in the mean number of upper respiratory tract visits over time; the medical records control group had no change in this parameter. The supplements were well tolerated; per parental report. CONCLUSIONS: “Use of these nutritional supplements was acceptable to the inner-city Latino families and their young children, and was associated with a decrease in upper respiratory tract pediatric visits over time; this approach therefore deserves further research and attention. Larger, controlled trials are warranted to assess the utility of cod liver oil (of acceptable purity and taste) and a children's multi-vitamin/mineral preparation containing selenium, both for the prevention of otitis media and the acceptability of delayed prescription of antibiotics for this disorder.”

TITLE: Antioxidants, oxidative stress, and pulmonary function in individuals diagnosed with asthma or COPD. Department of Social and Preventive Medicine, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.

 AUTHORS: Ochs-Balcom HM, Grant BJ, Muti P, Sempos CT, Freudenheim JL, Browne RW, McCann SE, Trevisan M, Cassano PA, Iacoviello L, Schunemann HJ.

JOURNAL: Eur J Clin Nutr. 2006 Aug;60(8):991-9. Epub 2006 Feb 15

The objective of this study of 218 persons with chronic airflow limitation, recruited randomly from the general population of Erie and Niagara counties, New York State, USA, was to investigate the association between antioxidant nutrients and markers of oxidative stress with pulmonary function in persons with chronic airflow limitation. The study explored the association of antioxidant nutrients and markers of oxidative stress with forced expiratory volume in the first second (FEV1%) and forced vital capacity (FVC%). After adjustment for covariates, multiple linear regression analysis showed that serum beta-cryptoxanthin, lutein/zeaxanthin, and retinol, and dietary beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, vitamin C, and lycopene were positively associated with FEV1% (P < 0.05, all associations). Serum vitamins beta-cryptoxanthin, lutein/zeaxanthin, and lycopene, and dietary beta-cryptoxanthin, beta-carotene, vitamin C, and lutein/zeaxanthin were positively associated with FVC. CONCLUSION: “These results support the hypothesis that an imbalance in antioxidant/oxidant status is associated with chronic airflow limitation, and that dietary habits and/or oxidative stress play contributing roles.”

TITLE: Dietary antioxidants and asthma in adults Department of Public Health and Primary Care, Institute of Public Health, Cambridge, UK.

AUTHORS: Patel BD, Welch AA, Bingham SA, Luben RN, Day NE, Khaw KT, Lomas DA, Wareham NJ.

JOURNAL: Thorax. 2006 May;61(5):388-93. Epub 2006 Feb 7.

This study was undertaken to assess several antioxidant nutrients which have been reported to be inversely associated with asthma. A nested case-control study was performed in 515 adults with physician diagnosed asthma and 515 matched controls using dietary data obtained from 7 day food diaries. The main outcome measures were physician diagnosed asthma and current symptomatic asthma (diagnosed asthma and self-reported wheeze within the previous 12 months). Cases were similar to controls in age, sex, social class, and daily energy intake but had a lower median intake of fruit. 51.5% of the population reported zero consumption of citrus fruit; relative to these individuals, people who consumed greater than 46.3 g/day had a reduced risk of diagnosed and symptomatic asthma. In nutrient analysis, dietary vitamin C and manganese were inversely and independently associated with symptomatic asthma, but only manganese was independently associated with diagnosed asthma. Adjusted plasma levels of vitamin C were significantly lower in symptomatic cases than in controls. CONCLUSIONS: “Symptomatic asthma in adults is associated with a low dietary intake of fruit, the antioxidant nutrients vitamin C and manganese, and low plasma vitamin C levels. These findings suggest that diet may be a potentially modifiable risk factor for the development of asthma.”

TITLE: Oxidative stress and antioxidant deficiencies in asthma: potential modification by diet. Asthma & Allergy Research Institute (Inc) and Centre for Asthma, Allergy & Respiratory Research, The University of Western Australia, Perth, Australia.

AUTHORS: Misso NL, Thompson PJ.

JOURNAL: Redox Rep. 2005;10(5):247-55.

It has been shown the lungs of asthmatic patients are exposed to oxidative stress due to the generation of reactive oxygen and nitrogen species as a consequence of chronic airway inflammation. Oxidative stress may also reduce glutathione levels and cause inactivation of antioxidant enzymes such as superoxide dismutase, with a consequent increase in apoptosis, shedding of airway epithelial cells and airway remodelling. The oxidant/antioxidant equilibrium in asthmatic patients may be further perturbed by low dietary intakes of the antioxidant vitamins C and E, selenium and flavonoids, with a consequent lowering of the concentrations of these and other non-dietary antioxidants such as bilirubin and albumin in plasma and airway epithelial lining fluid. Although supplementation with vitamins C and E appears to offer protection against the adverse effects of ozone, recent randomised, placebo-controlled trials of vitamin C or E supplements for patients with mild asthma have not shown significant benefits over standard therapy. However, genetic variation in glutathione S-transferase may influence the susceptibility of asthmatic individuals to oxidative stress and the extent to which they are likely to benefit from antioxidant supplementation. CONCLUSIONS: Long-term prospective trials are required to determine whether modification of dietary intake will benefit asthma patients and reduce the socio-economic burden of asthma in the community.