Potential Role of Antioxidant Food Supplements, Preservatives and Colorants in the Pathogenesis of Allergy and Asthma

Abstract

A significant increase in the incidence of allergy and asthma has been observed during the past decades. The background of this phenomenon has not been well explained, but changes in lifestyle and habits are heavily discussed as contributing factors. Among these is a too clean environment, which may predispose individuals to increased sensitivity to allergic responses. Also the increase in dietary supplements including preservatives and colorants may contribute to this. In vitro, we and others have shown in freshly isolated human peripheral blood mononuclear cells that antioxidant compounds like vitamins C and E as well as food preservatives and colorants exert significant suppressive effects on the Th1 immune activation cascade. The effects observed may be based on the interaction of antioxidant compounds with proinflammatory cascades involving important signal transduction elements such as nuclear factor-ĸB. Although only obtained in vitro, these results show an anti-inflammatory property of compounds which could shift the Th1-Th2-type immune balance towards Th2-type immunity. This review article discusses the potential role of increased use of antioxidant food supplements as well as preservatives and colorants in the increase in allergy and asthma in the Western world.

Antioxidants, inflammation and cardiovascular disease

“…Excessive antioxidant consumption may lead to adverse reactions ranging from favoring of Th2-type responses such as allergy and asthma to an increase of mortality [166][167][168] . So far, for patients who respond well to statin/niacin therapy, additional supplementation might only be advantageous when nutritional deficiencies are still detectable, however this hypothesis has to be investigated in more detail.…”

Tryptophan and Nitric Oxide in Allergy

“…If an allergen is presented, Th2-type cytokines are produced in a high concentration, and this condition can strengthen the Th2-type immune response. Under antioxidant-loaded conditions, allergic response already initially becomes stronger when an allergen is met, than in conditions with normal antioxidant levels (Zaknun et al 2012 ).…”

“…At this time point, the sensitization to a specifi c allergen is stored. If this antigen is present at another time, it can bind to the IgE of mast cells and activate several cascades like vasodilation, mucous secretion, and nerve stimulation of muscle contraction (Zaknun et al 2012 ). However, not every Th2-type response is characterized by IgE production.…”

“…An intake of dietary antioxidants can counteract oxidation processes by scavenging ROS and other redox-sensitive molecules and therefore protect against cellular damage (Schroecksnadel et al 2007 ;Jenny et al 2011 ). However, if antioxidants are present in a normal milieu without infl ammation, an excess can shift the Th1-type immune response to Th2-type immunity, which can promote or accelerate allergic reactions when an allergen is met (Zaknun et al 2012 ).…”

“…These are usually declared only as fi ne print. Food preservatives like sodium sulfi te or benzoate but also colorants like curcumin or betalain are widely known for their antioxidant activity (Zaknun et al 2012 ). However, a well-functioning human organism does not need extra antioxidant supplementation; the content in the normal Western diet is suffi cient.…”