Specific allergen profiles of peanut foods and of diagnostic or therapeutic allergenic products.
RATIONALE: 'Generic' immunoassays for peanut cannot discriminate between allergen levels in peanut derived food products or therapeutics. Clinical trials of oral immunotherapy are strengthened by using standardized peanut preparations, with defined doses of major allergens. OBJECTIVE: This paper describes measurement of Ara h 1, Ara h 2 and Ara h 6 in peanut foods and in peanut flour extracts used for allergy diagnosis and oral immunotherapy. METHODS: Monoclonal antibody-based enzyme immunoassays for Ara h 1, Ara h 2 and Ara h 6 were used to compare allergen levels in peanut (n=19) and tree nut (n=16) butter, peanut flour (n=11); oils (n=8); extracts used for diagnosis and oral immunotherapy (n=5); and the National Institute for Standards and Technology Peanut Butter Standard Reference Material® 2387. RESULTS: Roasted peanut butters contained 991-21,406μg/g Ara h 1 and exceeded Ara h 2 and Ara h 6 levels by 2-4 fold. Similarly, NIST SRM 2387 contained 11,275μg/g Ara h 1; 2,522μg/g Ara h 2 and 2,036μg/g Ara h 6. In contrast, peanut flours contained 787-14,631μg/g Ara h 2 and exceeded Ara h 1 levels by 2-20 fold. Flour extracts used for oral immunotherapy contained 394-505μg/ml Ara h 1, 1,187-5,270μg/ml Ara h 2 and 1,104-8,092μg/ml Ara h 6. In most cases, specific peanut allergens were not detected in tree nut butters or peanut oils. CONCLUSIONS: The results show marked differences in specific peanut allergen profiles in peanut butter, flour and peanut preparations for clinical use. Roasting may increase Ara h 1 levels in peanut butter. Variability in allergen levels could affect the outcome of clinical trials of peanut oral immunotherapy, especially with respect to Ara h 1. Specific allergen measurements will improve standardization and provide accurate dosing of peanut preparations that are being used for oral immunotherapy.
Low Food Allergy Prevalence Despite Delayed Introduction of Allergenic Foods—Data from the GUSTO Cohort.
BACKGROUND: There is mounting evidence that early introduction of allergenic food decreases the risk of food allergy development, especially in high-risk infants with eczema. However, there is a lack of data to suggest whether this association holds true in Asian populations. OBJECTIVE: To investigate the relationship between the timing of introduction of allergenic foods and food allergy outcomes in infants in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) study. METHODS: The GUSTO cohort recruited 1152 mothers of Chinese, Malay, and Indian ethnicity who had singleton, naturally conceived pregnancies and followed their offspring prospectively. Information on demographic characteristics, child health, infant feeding practices, and a convincing history of IgE-mediated food allergy was obtained from interviewer-administered questionnaires at multiple time points. Corroborative skin prick tests to food allergens were performed at 18 and 36 months. RESULTS: Most of the infants were introduced to egg (49.6%), peanut (88.7%), and shellfish (90.2%) after age 10 months. Food allergy prevalence was, however, very low between age 12 and 48 months: egg, 0.35% to 1.8%; peanut allergy, 0.1% to 0.3%; and shellfish, 0.2% to 0.9%. There were no significant associations between the timing of introduction of allergenic foods and the development of food allergy, adjusted for confounders including breast-feeding and eczema. CONCLUSIONS: Food allergy rates in Singapore are low despite delayed introduction of allergenic foods. Early introduction of allergenic foods may thus not be necessary in populations in which overall food allergy prevalence is low, and thus infant feeding recommendations should be carefully tailored to individual populations.
Methods in Allergy/Immunology: Food Challenges.
Since there is no in vitro test, which can accurately predict the clinical relevance of a sensitization to food, the oral food challenge still remains the most reliable procedure to confirm or exclude food allergy and to assess the development of tolerance in children with potentially transient food allergies such as to cow's milk, hen's egg, wheat or soy. Although in the last few years component-resolved diagnostic has improved the food allergy diagnostics, especially in peanut and tree nut allergy, the majority of patients still need to undergo oral food challenge. The following paper will describe in whom and how to perform an oral food challenge as well as its interpretation of the results with a focus on suspected IgE-mediated food allergy.
The role of environmental exposure to peanut in the development of clinical allergy to peanut.
The presence of peanut allergy has increased over the years and still remains one of the most common causes of food-related anaphylaxis. The way in which peanut sensitization occurs has been explored, such as via maternal consumption in pregnancy, via breast milk and through a disrupted skin barrier. It has previously been shown that environmental exposure to aeroallergens in household dust can be a risk factor for the development of allergic asthma. However, it is likely that the combination of cutaneous sensitisation via a disrupted skin barrier (i.e. children with eczema especially those with filaggrin mutations) and the interaction with environmental peanut exposure influences the development of peanut allergy. This review aims to explore the current evidence of how environmental exposure to peanut affects the development of peanut allergy.
The concordance between component tests and clinical history in British adults with suspected pollen-food syndrome to peanut and hazelnut.
BACKGROUND: Mild oropharyngeal symptoms to peanut/hazelnut occur in ~30% of patients with pollen-food syndrome (PFS). Component tests are considered a useful adjunct to the diagnosis and may help differentiate PFS from those at a risk of anaphylaxis due to storage protein/lipid transfer protein (LTP) sensitisation. AIMS: To assess concordance between component tests and clinical history in suspected PFS to peanut/hazelnut in a specialist clinic. METHODS: Adult patients were classified into PFS (group 1, n=69) and PFS with mild systemic symptoms (group 2, n=45) based on clinical history. Specific IgE (sIgE) of ≥0.35 kUA/L was considered positive as per manufacturers’ recommendation. Kappa (κ) inter-rater agreement was calculated for concordance between clinical classification and test profiles. RESULTS: Group 1 hazelnut: 85% monosensitised to Cor a1, 12% to storage protein/s or LTP and 3% negative to all components. Group 1 peanut: 41% monosensitised to Ara h8, 44% to storage protein/s or ±LTP and 15% negative to all components. Group 2 hazelnut: 67% monosensitised to Cor a1, 16% sensitised to storage protein/s and 17% negative to all components. Group 2 peanut: 19% monosensitised to Ara h8, 62% sensitised to storage protein/s and/or LTP and 19% negative to all components. SIgE to Ara h8 and Cor a1 were greater in group 1 versus group 2: (median (IQR) kUA/L; hazelnut: 12.1 (7.8-25.2) vs 2.4 (0.36-6.3), p<0.001; peanut: 2.4 (0.10-21.1) vs 0.3 (0-3), p<0.01)). CONCLUSION: Concordance between component tests and clinical history for adults with PFS was good for hazelnut (κ=0.63) but poor for peanut (κ=âˆ'0.12). Food challenges are warranted in discordant cases for an accurate diagnosis.
Nut and peanut butter consumption and the risk of esophageal and gastric cancer subtypes.
Background: Nut consumption has been associated with decreased risk of colorectal, endometrial, lung, and pancreatic cancers. Polyphenols, fiber, vitamins, and minerals in nuts may confer this observed protective effect. To our knowledge, no prospective study has evaluated the effect of nut consumption on esophageal and gastric cancers. Objective: The objective was to evaluate the associations between nut and peanut butter consumption and the risk of esophageal and gastric cancers and their different subtypes. Design: In this study we used data from the NIH-AARP Diet and Health Study, which enrolled 566,407 persons who were 50-71 y old at baseline (1995-1996). The median follow-up time was 15.5 y. Intakes of nuts and peanut butter were assessed through the use of a validated food-frequency questionnaire. We used Cox proportional hazard models to estimate HRs and 95% CIs for esophageal and gastric cancers and their subtypes. Results: We identified 966 incident cases of esophageal adenocarcinomas, 323 cases of esophageal squamous cell carcinoma, 698 cases of gastric cardia adenocarcinoma, and 732 cases of gastric noncardia adenocarcinoma. Compared with those who did not consume nuts or peanut butter [lowest category of consumption (C0)], participants in the highest category of nut consumption (C3) had a lower risk of developing gastric noncardia adenocarcinoma [C3 compared with C0, HR: 0.73 (95% CI: 0.57, 0.94)]. This inverse association was also seen for peanut butter consumption [C3 compared with C0, HR: 0.75 (95% CI: 0.60, 0.94)]. We observed no significant associations between the highest and lowest intakes of nuts or peanut butter and the risk of gastric cardia adenocarcinoma, esophageal adenocarcinoma, or esophageal squamous cell carcinoma. Conclusions: Among older American adults, both nut and peanut butter consumption were inversely associated with the risk of gastric noncardia adenocarcinoma.
Effect of interdisciplinary care on weight loss: a randomised controlled trial.
To determine the effectiveness of a novel interdisciplinary treatment compared with usual care on weight loss in overweight and obese adult volunteers. DESIGN: Single blinded controlled trial. Participants randomly assigned to usual care (C, general guideline-based diet and exercise advice), intervention (I, interdisciplinary protocol) or intervention + a healthy food supplement (30 g walnuts/day) (IW). SETTING: Community based study, Illawarra region, south of Sydney, Australia. PARTICIPANTS: Generally well volunteer adult residents, 25-54 years, body mass index (BMI) 25-40kg/m2 were eligible. At baseline 439 were assessed, 377 were randomised, 298 completed the 3-month intensive phase and 178 completed the 12-month follow-up. INTERVENTIONS: Treatment was provided at clinic visits intensively (0 months, 1 month, 2 months, 3 months) then quarterly to 12 months. Support phone calls were quarterly. All participants underwent blinded assessments for diet, exercise and psychological status. PRIMARY AND SECONDARY MEASURES: The primary outcome was difference in weight loss between baseline and 12 months (clinically relevant target 5% loss). Secondary outcomes were changes in blood pressure, fasting blood glucose and lipids, and changes in diet, exercise and psychological parameters. RESULTS: At 12 months, differences in weight loss were identified (p<0.001). The I group lost more than controls at 3 months (91.11 (92.23,90.00), p<0.05) and the IW more than controls at 3 months (91.25 (92.35,90.15), p<0.05) and 6 months (92.20 (93.90,90.49), p<0.01). The proportion achieving 5% weight loss was significantly different at 3 months, 6 months and 9 months (p=0.04, p=0.03, p=0.03), due to fewer controls on target at 3 months, 6 months and 9 months and more IW participants at 6 months. Reductions in secondary outcomes (systolic blood pressure, blood glucose/lipid parameters and lifestyle measures) followed the pattern of weight loss. CONCLUSIONS: An interdisciplinary intervention produced greater and more clinically significant and sustained weight loss compared with usual care. The intensive phase was sufficient to reach clinically relevant targets, but long-term management plans may be required.
Post-prandial effects of hazelnut-enriched high fat meal on LDL oxidative status, oxidative and inflammatory gene expression of healthy subjects: a randomized trial.
OBJECTIVE: Postprandial oxidative stress is characterized by an increased susceptibility of the organism towards oxidative damage after consumption of a meal rich in lipids and/or carbohydrates. Micronutrients modulate the immune system and exert a protective action by reducing low-density lipoproteins oxidation (ox-LDL) via induction of antioxidant enzymes. SUBJECTS AND METHODS: The clinical study was a randomized and cross-over trial, conducted through the CONSORT flowchart. We evaluated the gene expression of 103 genes related to oxidative stress (HOSp) and human inflammasome pathways (HIp), and ox-LDL level at fasting and after 40 g raw "Tonda Gentile delle Langhe" hazelnut consumption, in association with a McDonald's® Meal (McDM) in 22 healthy human volunteers. RESULTS: Ox-LDL levels significantly increased comparing no dietary treatment (NDT) vs. McDM, and decreased comparing McDM vs. McDM + H (p<0.05). Percentage of significant genes expressed after each dietary treatment were the follows: (A) NDT vs. McDM: 3.88% HIp and 17.48% HOSp; (B) NDT vs. McDM + H: 17.48% HIp and 23.30% HOSp; (C) McDM vs. McDM + H: 17.48% HIp and 33.98% HOSp. CONCLUSIONS: Hazelnut consumption reduced post prandial risk factors of atherosclerosis, such as ox-LDL, and the expression of inflammation and oxidative stress related genes. Chronic studies on larger population are necessary before definitive conclusions.
Consuming Almonds vs. Isoenergetic Baked Food Does Not Differentially Influence Postprandial Appetite or Neural Reward Responses to Visual Food Stimuli.
Nuts have high energy and fat contents, but nut intake does not promote weight gain or obesity, which may be partially explained by their proposed high satiety value. The primary aim of this study was to assess the effects of consuming almonds versus a baked food on postprandial appetite and neural responses to visual food stimuli. Twenty-two adults (19 women and 3 men) with a BMI between 25 and 40 kg/m² completed the current study during a 12-week behavioral weight loss intervention. Participants consumed either 28 g of whole, lightly salted roasted almonds or a serving of a baked food with equivalent energy and macronutrient contents in random order on two testing days prior to and at the end of the intervention. Pre- and postprandial appetite ratings and functional magnetic resonance imaging scans were completed on all four testing days. Postprandial hunger, desire to eat, fullness, and neural responses to visual food stimuli were not different following consumption of almonds and the baked food, nor were they influenced by weight loss. These results support energy and macronutrient contents as principal determinants of postprandial appetite and do not support a unique satiety effect of almonds independent of these variables.
Attenuation of cadmium-induced decline in spatial, habituation and recognition memory by long-term administration of almond and walnut supplementation: Role of cholinergic function.
Excessive exposure of cadmium which is regarded as a neurotoxin can stimulate aging process by inducing abnormality in neuronal function. It has been reported that supplementation of almond and walnut attenuate age-related memory loss. Present study was designed to investigate the weekly administration of cadmium for one month on learning and memory function with relation to cholinergic activity. Cadmium was administered at the dose of 50 mg/kg/week. Whereas, almond and walnut was supplemented at the dose of 400 mg/kg/day along with cadmium administration to separate set of rats. At the end of experiment, memory function was assessed by Morris water maze, open field test and novel object recognition test. Results of the present study showed that cadmium administration significantly reduced memory retention. Reduced acetylcholine levels and elevated acetyl cholinesterase activity were also observed in frontal cortex and hippocampus of cadmium treated rats. Malondialdehyde levels were also significantly increased following the administration of cadmium. Daily supplementation of almond and walnut for 28 days significantly attenuated cadmium-induced memory impairment in rats. Results of the present study are discussed in term of cholinergic activity in cadmium-induced memory loss and its attenuation by nuts supplementation in rats.