Here is a list of eleven main anti-allergic foods.
1. Vegetable and Fruit Concentrate:
Current therapies such as inhaled steroids, long-acting beta-agonist bronchodilators, antihistamines and immuno-modulators may control the symptoms of allergic asthma but fail to modify the underlying disease. Excessive use of steroids and other immune-suppressants alter the patient’s quality of life, produce undesirable toxicities, and increase the risk of other pathologies such as diabetes.
Hence, novel therapeutic options to manage asthma are desirable. A combination of fruit plus vegetable concentrate, fish oil and probiotics (FVFP supplement) was found to be effective in controlling improved pulmonary function in asthmatic children in a 16-week school-based double-blind placebo-controlled randomized trial.
A reduction in the levels of IgE, histamine, and interleukin (IL)-1β in serum by bamboo salt (BS -a specially processed salt prepared from sun-dried salt (SDS) and bamboo in Korea) was reported by Kim et al. (2012). The number of eosinophil and infiltration of mast cells also decreased on BS treatment in ovalbumin sensitized mice.
The other benefits of BS treatment included inhibition of caspase-1 activity, production of IL-1β and thymic stromal lymphopoietin in the nasal mucosa tissue. Thus the authors confirmed the in vitro anti-allergic and anti-inflammatory effects of BS in allergic rhinitis mice models.
Though numerous synthetic-aldose reductase inhibitors have been tested, these have not been very successful clinically. In the course of identifying and testing new and effective ARIs, Reddy et al (2011) have evaluated a number of traditional and common dietary sources and found that some spice principles and fruits & vegetables have the potential to inhibit aldose reductase (ALR2) under in vitro conditions and in animal models.
Flavonoids are abundantly found in fruits, vegetables, herbs and spices, and some flavonoids have been shown to inhibit ALR2. Rutin is one of the commonly found dietary flavonols. Varma et al (1975) demonstrated that rutin may have ARI activity.
Prominent inhibitory property was found in spinach, cumin, fennel, lemon, basil and black pepper with an approximate IC50 of 0.2 mg/mL with an excellent selectivity towards aldose reductase. As against this, 10 to 20 times higher concentrations were required for 50 per cent inhibition of aldehyde reductase.
2. Fenugreek:
Fenugreek extract was found to reduce ear thickness as well as the infiltration of eosinophils and mast cells. In homogenized ear, the production of IL-4, IL-5, IL-13, and IL-1β was suppressed. Their differentiation into Th2 cells was also prevented in the splenocytes of OVA-induced allergic mice. This confirms the traditional practice of fenugreek being useful in treating allergic inflammatory diseases.
3. Date Palm (Phoenix Dactylifera L.):
Oral administration of a hot water extract of matured fruit of the date palm resulted in significantly lower sneezing and nose rubbing events in mice than in controls. Karasawa and Otani (2012) proposed that some polyphenols in the date may reduce mite-induced allergic symptoms in mice via a decrease in the number of IgE-producing plasma cells and high-affinity IgE receptor-expressing mast cells.
4. Mango-Ginger (Curcuma Amada Roxb.):
Anti-inflammatory activity, platelet aggregation inhibitory activity, cytotoxicity and anti-allergic activity are some of the biological activities of mango ginger. The major chemical components that might be responsible to these benefits include phytochemicals such as phenolic acids, volatile oils, curcuminoids and terpenoids like difurocumenonol, amadannulen and amadaldehyde.
5. Mangosteen (Garcinia Mangostana):
Alpha- and γ-mangostin, which are the major xanthones purified from a mangosteen exhibit a wide range of anticancer, antioxidant, and anti-inflammatory activities. In addition, administration of α- and γ-mangostins significantly reduced the major patho-physiological features of allergic asthma, including inflammatory cell recruitment into the airway, AHR and increased levels of Th2 cytokines suggesting the therapeutic potential of α- and γ-mangostin in the treatment of allergic asthma.
6. Picholine Olive Oil:
Picholine olive oil from Montpellier in Southern France showed an inhibitory effect on the chemical mediator release and decreased expressions of genes related to type I allergy in RBL-2H3 cells as Picholine olive oil has high content of flavonoids, especially apigenin.
7. Bilberry (Vaccinium Myrtillus L.):
Bilberry is one of the best sources of anthocyanins and provides 15 anthocyanin analogues, each composed of one of five anthocyanidins and one of three glucosides. In addition, it was recently shown that oral administration of cyanidin-3-o-β-D-glucoside, an anthocyanin found in black rice, as well as its metabolite cyanidin, promotes anti-scratching behavior in pruritogen-induced acute pruritus in mice.
Treatment with Bilberon-25 significantly attenuated the TNCB-induced increase in scratching behaviour, but dexamethasone did not. In contrast, ear swelling was ameliorated by dexamethasone treatment, and significantly decreased by Bilberon-25. Hence, Yamaura et al (2011) reported that anthocyanins from bilberry might be beneficial for the treatment of chronic allergic contact dermatitis.
It has been reported that anthocyanins are particularly sensitive to thermal treatment and are easily hydrolyzed to anthocyanidins when exposed to high temperatures. So, Yamaura et al (2012) on further experimentation concluded that the anthocyanin- rich but not anthocyanidin-rich bilberry extract may be a useful dietary supplement for skin diseases involving pruritic symptoms, such as chronic allergic contact dermatitis, atopic dermatitis, and rhinitis.
8. Vitamin D:
Vitamin D deficiency has been reported to be a risk factor for allergic asthma in children. Vitamin D supplementation was found to ameliorate clinical signs of mild, moderate and severe atopic dermatitis according to SCORAD (Scoring Atopic Dermatitis) and TIS value index (Three Item Severity score) and it is also said to be a safe and well-tolerated form of therapy.
Similarly, Hart (2013) and Agarwal et al. (2013) found vitamin D supplementation to reduce airway hypersensitivity and allergic airway inflammation in animals. In children cow’s milk allergy, adequate intake of vitamin D showed a positive correlation with serum concentration of 25-hydroxyl vitamin D. Hartmann et al (2012) provided evidence that systemic Vitamin D Receptor (VDR) agonist treatment may improve allergen-triggered eczema in vivo.
9. Food Hydrolysates (Whey/Casein Hydrolysate):
The whey hydrolysate as well as casein hydrolysate was found to be equally effective in food allergies. The symptom-based score (a tool useful to evaluate the efficacy of dietary treatment in infants with cow’s milk protein allergy) developed by Vandenplas et al (2013) showed statistically significant reductions in both groups. The total and specific IgE and skin prick test results were similar. Further, the whey hydrolysate standard formula sequence led to better growth at the age of 1 year than the other three feeding regimens tested.
A follow up study of infants’ upto 5 years of age showed a significant lowering in the cumulative incidence of atopic disease in the breast-fed as well as the whey hydrolysate group of children; but soy formula was not effective.
Similarly, in the 1860 month period, prevalence of eczema and severity were less in the whey hydrolysate group compared with the other groups. Exclusive breast-feeding or feeding with a partial whey hydrolysate formula is associated with lower incidence of atopic disease and food allergy. This is a cost-effective approach to the prevention of allergic disease in children.
10. Phytochemicals:
Currently, there is a renewed interest in the use of phytochemicals in inflammation and allergic diseases. Fisetin (3,7,3′,4′-tetrahydroxyflavone), a naturally occurring bioactive flavonol, has been shown to inhibit NF-κB activity. Phenolic acids and polyphenols, such as flavonoids, are the best studied natural substances known to possess an anti-inflammatory and anti-allergic as well as immune-modulating potential.
Though several phytochemicals have been investigated for their anti-allergic activity, the mechanism of action could not be elucidated so far which has limited their therapeutic application.
11. Probiotics:
In patients suffering from multiple food allergies, induction of oral tolerance by specific probiotics continues to attract research interest.
Due to their immuno-modulatory properties, several probiotic organisms have been found to be effective and safe in controlling the food allergies. The benefits of probiotics in various types of food allergies and the mode of action are discussed below.
Probiotics are non-pathogenic microorganisms which, when ingested, exert a positive influence on the health or physiology of the host. Their mechanism of action and effects are now studied using the same pharmacological approach as for drugs. Randomized double-blind studies have provided evidence of probiotic effectiveness for the treatment and prevention of acute diarrhea and antibiotic-induced diarrhea, as well as for the prevention of cow milk-induced food allergy in infants and young children.
Gut micro biota composition can be used to discriminate between allergic and healthy children, and the distinction may precede clinical manifestations of disease. Breast milk provides the first inoculum of bacteria, which influences the risk of becoming allergic later in life. Bifidobacterium species are major determinants of disease risk.
Specific probiotics may modulate early microbial colonization, which represents the first intervention target in allergic disease, together with their ability to reverse the increased intestinal permeability, characteristic of children with atopic eczema and food allergy. A balanced gut micro-biota is crucial for the development of healthy immuno-regulation and gut barrier function to allow brisk immune responses to pathogens and systemic hypo-responsiveness to harmless antigens such as food.
The clinical situations studied include prevention or treatment of lactose intolerance and allergy (especially atopic eczema), apart from other antibiotic- associated disorders. The potential application of probiotics on many other effects is under investigation.
However, according to Singh et al. (2013) many of these clinical studies require validation before applying these results to clinical realm. Analyzing the results from meta-analyses and systematic reviews that combine results of studies from different types of probiotics to examine the effects in any disease state, Minocha (2009) said that specific strains are effective only in specific disease states.
A large number of people, as they age, experience a decline in the level of lactase (β-galactosidase) in the intestinal brush border mucosa. This decline causes lactose to be incompletely absorbed, resulting in flatus, bloating, abdominal cramps, and moderate-to-severe diarrhoea i.e. Lactose mal-absorption. Several studies have demonstrated that, during the fermentative process in the production of yogurt, lactase is produced, which can exert its influence in the intestinal tract.
The organisms commonly used for the production of yogurt are Lactobacillus bulgaricus and Streptococcus salivarius subsp. Thermophilic Kim and Gilliland (1983) found that feeding yogurt to lactose-intolerant individuals caused a significant reduction in the level of breath hydrogen compared with that in subjects who were fed milk, thus proving its benefit.
Supplementation with the probiotic Lactobacillus reuteri reduced the incidence of IgE-associated allergic disease in infancy, but did not lead to a lower prevalence of respiratory allergic disease in school age.
Studies have reported a significant reduction in asthma and eczema from supplementation with a mixture of galacto- and fructo-oligosaccharide (GOS/FOS 9:1 ratio) (8 g/L) to infants at high risk of allergy; and in eczema from supplementation with GOS/FOS (9:1) (6.8 g/L) and acidic oligosaccharide (1.2 g/L) in infants not selected for allergy risk.
But Osborn and Sinn (2013) after reviewing the available work on high risk infants concluded that further research is needed before routine use of prebiotics (oligosaccharide) can be recommended for prevention of allergy in formula fed infants. There is some evidence that a prebiotic supplement added to infant feeds may prevent eczema. It is unclear whether the use of prebiotic should be restricted to infants at high risk of allergy or may have an effect in low risk populations; or whether it may have an effect on other allergic diseases including asthma.
Though probiotic bacteria continue to represent the most promising intervention for primary prevention of allergic disease, Ismail et al. (2013) expressed the need for well-designed definitive intervention studies as a research priority.