Review and feature articleDiet as a risk factor for atopy and asthma
Section snippets
The antioxidant and lipid hypotheses
In 1994, we argued that the increases in asthma and atopic diseases were unlikely to be a consequence of the air we breathe becoming increasingly toxic.4 There had been well-documented decreases in atmospheric pollution and cigarette smoking, and there was little evidence for increased exposure to aeroallergens. Instead, we hypothesized that the increase in asthma and atopy had resulted from increasing population susceptibility. We noted that the increase in asthma and atopy had been preceded
Vitamin C
Water-soluble vitamin C provides intracellular and extracellular aqueous-phase antioxidant capacity primarily by scavenging oxygen free radicals and suppressing macrophage secretion of superoxide anions. In general, most studies of dietary vitamin C have reported beneficial associations with ventilatory function, a smaller number have reported associations with asthma, and very few, if any, have shown associations with atopic disease.
Many epidemiologic studies have demonstrated that dietary
Antioxidant intervention studies
The epidemiologic studies discussed above suggest that there are beneficial associations between asthma and atopic disease and dietary antioxidants, such as vitamin C, vitamin E, some carotenoids, selenium, and antioxidant-rich fruits. There have been many intervention studies, the majority of which have supplemented with vitamin C. Studies of vitamin E and selenium supplementation are few in number. In general, the results of these supplementation studies have been disappointing, with many
Antioxidants, asthma, and atopic disease: Possible mechanisms
The respiratory airways are particularly vulnerable to oxidative damage, and to counteract this, numerous enzymatic and nonenzymatic antioxidant defense mechanisms are present.34 In experimental models oxidants induce many features of asthma by inducing release of proinflammatory mediators, including cytokines, chemokines, and eicosanoid metabolites.35 Oxidant stress also activates gene expression of 2 pivotal inflammatory regulators, nuclear factor κB and activator protein 1.35
There is an
Observational studies of lipids
Several cross-sectional studies have reported beneficial associations between dietary fish intake, asthma, and atopic disease.51, 52 Hodge et al51 reported that in children aged 8 to 11 years the risk of current asthma was significantly reduced in those who included fresh oily fish in their diet. A number of studies of adult populations have reported no association between dietary fish intake and asthma, respiratory symptoms, and ventilatory function,53 and Takemura et al54 reported an adverse
Lipid intervention studies
As outlined above, investigation of asthma and dietary lipids has pursued the suggestion that asthma and atopy are a consequence of increasing n-6 PUFA intake and decreasing n-3 PUFA consumption and effects on inflammatory mediators and TH cell differentiation. Studies of atopic dermatitis have focused on reduced activity of Δ6-desaturase enzyme and consequent effects on epidermal structure-function and TH cell differentiation. This is probably why there has been an emphasis on increasing
Conclusion
Epidemiologic studies have reported associations between dietary antioxidant and lipid intakes and asthma and atopic disease. With the possible exception of n-6 PUFA supplementation for atopic dermatitis, a major criticism of the dietary hypotheses is the generally disappointing results of intervention studies. However, the realization that dietary habits are established early in life and that fetal and early life factors influence the development of asthma and atopic disease has moved the
References (78)
- et al.
Rising prevalence of allergy to peanut in children: data from 2 sequential cohorts
J Allergy Clin Immunol
(2002) - et al.
Eicosanoids and asthma: an update
Prostaglandins Leukot Essent Fatty Acids
(1995) - et al.
A new view of prostaglandin E regulation of the immune response
Immunol Today
(1991) - et al.
Relationship between dietary vitamin C intake and pulmonary function in the First National Health and Nutrition Examination Survey (NHANES 1)
Am J Clin Nutr
(1994) - et al.
Dietary vitamin E, IgE concentrations and atopy
Lancet
(2000) - et al.
Oxidative stress in allergic respiratory diseases
J Allergy Clin Immunol
(2002) - et al.
Why do poor people behave poorly? Variation in adult health behaviours and psychosocial characteristics by stages of the socioeconomic lifecourse
Soc Sci Med
(1997) - et al.
Oxidation-reduction (redox) controls fetal hypoplastic lung growth
J Surg Res
(2002) - et al.
The role of α-tocopherol in preventing disease: from epidemiology to molecular events
Mol Aspects Dis
(2003) - et al.
Effect of dietary vitamin E supplementation on murine nasal allergy
Am J Med Sci
(1999)
The flavonoid, quercetin, differentially regulates Th-1 (IFNgamma) and Th-2 (IL-4) cytokine gene expression by normal peripheral blood mononuclear cells
Biochim Biophys Acta
An increase in selenium intake improves immune function and poliovirus handling in adults with marginal selenium status
Am J Clin Nutr
Protection of mice from allergen induced asthma by selenite
J Biol Chem
The relationship between fish intake and the prevalence of asthma: the Tokorozawa Childhood asthma and Pollinosis Study
Prev Med
Essential fatty acid metabolism and its modification in atopic eczema
Am J Clin Nutr
Reduced levels of prostaglandin precursors in the blood of atopic patients: defective delta-6-desaturase function as a biochemical basis for atopy
Prostaglandins Leukot Med
Seasonal allergic rhinoconjunctivitis and fatty acid intake: a cross sectional study in Japan
Ann Epidemiol
Reduced asthma symptoms with n-3 fatty acid ingestion are related to 5-series leukotriene production
Am J Clin Nutr
Placebo controlled trial of essential fatty acid supplementation in atopic dermatitis
Lancet
Three year outcomes of dietary fatty acid modification and house dust mite reduction in the Childhood Asthma Prevention Study
J Allergy Clin Immunol
γ-Linolenic acid supplementation for prophylaxis of atopic dermatitis—a randomized controlled trial in infants at high familial risk
Am J Clin Nutr
Fish oil supplementation in pregnancy modifies neonatal allergen specific immune responses and clinical outcomes in infants at high risk of atopy: a randomized, controlled trial
J Allergy Clin Immunol
Epidemiological trends
Respiratory symptoms and atopy in children in Aberdeen: questionnaire studies of a defined school population repeated over 35 years
BMJ
Increase in asthma: a more toxic environment or a more susceptible population?
Thorax
The increase in hay fever: pollen, particulate matter and SO2 in ambient air
QJM
Dietary fat and asthma: is there a connection?
Eur Respir J
Eicosapentaeanoic acid inhibits prostaglandin D2 generation by inhibiting cyclo-oxygenase-2 in cultured human mast cells
Clin Exp Allergy
Fatty acids and lymphocyte functions
Br J Nutr
Children's lung function and antioxidant vitamin, fruit, juice and vegetable intake
Am J Epidemiol
Antioxidants and pulmonary function: the third National Health and Nutrition Examination Survey (NHANES III)
Am J Epidemiol
Dietary antioxidant vitamin intake and lung function in the general population
Am J Respir Crit Care Med
Relationship of serum antioxidants to asthma prevalence in youth
Am J Respir Crit Care Med
Serum vitamin levels and the risk of asthma in children
Am J Epidemiol
Antioxidant intake and adult-onset wheeze: a case-control study
Eur Respir J
Bronchial reactivity and dietary antioxidants
Thorax
The relation of serum levels of antioxidant vitamins C and E, retinol and carotenoids with pulmonary function in the general population
Am J Respir Crit Care Med
Diet, lung function and lung function decline in a cohort of 2512 middle aged men
Thorax
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Disclosure of potential conflict of interest: all authors—none disclosed.