Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “NUTS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed2004

Speciation of arsenic in different types of nuts by ion chromatography-inductively coupled plasma mass spectrometry.

In this work the quantitative determination and analytical speciation of arsenic were undertaken in different types of nuts, randomly purchased from local markets. The hardness of the whole nuts and high lipid content made the preparation of this material difficult for analysis. The lack of sample homogeneity caused irreproducible results. To improve the precision of analysis, arsenic was determined separately in nut oil and in the defatted sample. The lipids were extracted from the ground sample with the two portions of a mixture of chloroform and methanol (2:1). The defatted material was dried and ground again, yielding a fine powder. The nut oil was obtained by combining the two organic extracts and by evaporating the solvents. The two nut fractions were microwave digested, and total arsenic was determined by inductively coupled plasma mass spectrometry (ICP-MS). The results obtained for oils from different types of nuts showed element concentration in the range 2.9-16.9 ng g(-)(1). Lower levels of arsenic were found in defatted material (<0.1 ng g(-)(1) with the exception of Brazil nuts purchased with and without shells, 3.0 and 2.8 ng g(-)(1) respectively). For speciation analysis of arsenic in nut oils, elemental species were extracted from 2 g of oil with 12 mL of chloroform/methanol (2:1) and 8 mL of deionized water. The aqueous layer, containing polar arsenic species, was evaporated and the residue dissolved and analyzed by ion chromatography-ICP-MS. The anion exchange chromatography enabled separation of As(III), dimethylarsinic acid (DMAs(V)), monomethylarsonic acid (MMAs(V)), and As(V) within 8 min. Several types of nuts were analyzed, including walnuts, Brazil nuts, almonds, cashews, pine nuts, peanuts, pistachio nuts, and sunflower seeds. The recovery for the speciation procedure was in the range 72.7-90.6%. The primary species found in the oil extracts were As(III) and As(V). The arsenic concentration levels in these two species were 0.7-12.7 and 0.5-4.3 ng g(-)(1), respectively. The contribution of As in DMAs(V) ranged from 0.1 +/- 0.1 ng g(-)(1) in walnuts to 1.3 +/- 0.3 ng g(-)(1) in pine nuts. MMAs(V) was not detected in almonds, peanuts, pine nuts, sunflower seeds, or walnuts, and the highest concentration was found in pistachio nuts (0.5 +/- 0.2 ng g(-)(1)).

Arsenic↗
PubMed2005

The development and progression of allergy to multiple nuts at different ages.

The aims of this study were to define the development of sensitization and clinical allergy to multiple nut types by age, and to identify associations. This observational cross- sectional study was carried out in a tertiary level allergy clinic. Seven hundred and eighty four nut-allergic children, prospectively enrolled on first attendance with history of a type-1 allergic reaction shortly after definite nut ingestion with evidence of sensitization (presence of nut-specific IgE) by skin prick test (SPT) to peanut, Brazil, almond, hazel and walnut (positive > or = 3 mm). Details of exposure (tolerance or allergy) to each nut were obtained. The main outcome measures were mono or multi-sensitization (specific IgE to one or more than one nut type, demonstrated by SPT); mono or multi-allergy (clinical allergy to one or more than one nut type). By 2 yr of age at least 19% were multi-sensitized, and 2% multi-allergic. Increasing proportions were exposed to multiple nut types with increasing age (23% at 2 yr to 73% by 10 yr) and greater proportions were multi-sensitized (19% at 2 yr to 86% at 5-14 yr) and multi-allergic (2% at 2 yr to 47% at 14 yr). This study is the first to define the natural history of multiple nut allergies in childhood. New findings are that a large proportion of those aged 0-1 yr with nut allergy are already sensitized (have specific IgE) to multiple nut types, implying in utero or early life sensitization; those who present later in childhood are increasingly likely to be sensitized and clinically allergic to multiple nuts. This is related to increased duration of allergy and exposure to multiple nut types with age. Children with nut allergy should avoid all nut types from the onset.

Adolescent↗
PubMed2004

Prevalence and factors associated with the consumption of betel-nut among military conscripts in Taiwan.

OBJECTIVE: This study evaluates the prevalence of betel-nut chewing among military personnel stationed on Taiwan's offshore islands. Furthermore, this study examines variables to identify which may predict a greater predilection toward betel-nut chewing among the conscript population studied. METHODS: A cross-sectional mass screening was conducted of compulsory military service personnel stationed on Taiwan's offshore islands between August 1 and December 31, 2001. A total of 7574 military employees were included in this survey. Information regarding betel-nut chewing habits were ascertained using a standard structured questionnaire, which including the level and duration of betel-nut chewing as well as respondents' knowledge, attitude and practices with regard to consumption of this product. RESULTS: Conscripts were found to be less likely to chew betel-nut regularly while performing military service. There are 1535 (20.3%) of respondents reporting to habitually chew betel-nut prior to active duty shrank to 1048 (13.8%) after going on active-duty. The most reasons to chew betel-nut among the recruits after military services are curiosity (33.3%) and as a stimulant (29.8%). About 46% of military employees who currently chew betel-nut report an interest to quit in the future. The risk factors for betel-nut chewing include individual factors (e.g., age, education, knowledge, and attitude toward betel-nut chewing), lifestyle habits (e.g., cigarette smoking), and familial factors (e.g., consumption of betel-nut by parents). More interesting, the recruits had the habit of cigarette smoking associated with increase risk for betel-nut chewing (OR: 7.18; 95% CI: 5.66-9.20). CONCLUSIONS: Although the military has made considerable progress in reducing betel-nut chewing on military campuses, the prevalence of betel-nut chewing is still relatively high and, in 2001, affected about one quarter of all military personnel stationed on the abovementioned offshore islands. In future efforts to lower betel-nut consumption among high risk groups, targeting the group of conscripted military personnel described in this study should be considered.

Adult↗
PubMed2004

Midline carcinoma of children and young adults with NUT rearrangement.

PURPOSE: A balanced chromosomal translocation, t(15;19), resulting in the BRD4-NUT oncogene, has been identified in a lethal carcinoma of young people, a disease described primarily in case reports. We sought to amass a more definitive series of tumors with NUT and/or BRD4 gene rearrangements and to determine distinct clinicopathologic features. PATIENTS AND METHODS: Carcinomas (N = 98) in young individuals (median age, 32.5 years) were screened for NUT and BRD4 rearrangements using dual-color fluorescence in situ hybridization. Four published carcinomas with BRD4 and NUT rearrangements were also evaluated. Immunophenotypic analyses were performed. RESULTS: Eleven tumors had NUT gene rearrangements, including eight with BRD4-NUT fusions and three with novel rearrangements, which were designated as NUT variant. All NUT-rearranged carcinomas (NRCs) arose from midline epithelial structures, including the first example arising below the diaphragm. Patients were young (median age, 17.6 years). Squamous differentiation (seen in 82% of NRCs) was particularly striking in NUT-variant cases. In this first description of NUT-variant carcinomas, the average survival (96 weeks, n = 3) was longer than for BRD4-NUT carcinomas (28 weeks, n = 8). Strong CD34 expression was found in six of 11 NRCs but in zero of 45 NUT wild-type carcinomas. CONCLUSION: NRCs arise from midline structures in young people, and NRCs with BRD4-NUT are highly lethal, despite intensive therapies. NUT-variant carcinomas might have a less fulminant clinical course than those with BRD4-NUT fusions. CD34 expression is characteristic in NRCs and, therefore, holds promise as a diagnostic test for this distinctive clinicopathologic entity.

Adolescent↗
PubMed2002

The atopic dog as a model of peanut and tree nut food allergy.

BACKGROUND: Animal models are needed that mimic human IgE-mediated peanut and tree nut allergy. Atopic dogs have been previously used in a model of food allergy to cow's milk, beef, wheat, and soy, with the demonstration of specific IgE production and positive oral challenges similar to those seen in human subjects. OBJECTIVE: We sought to sensitize dogs to peanut, walnut, and Brazil nut and to assess whether sensitization is accompanied by clinical reactions and whether there is cross-reactivity among the different preparations. METHODS: Eleven dogs were sensitized subcutaneously by using an established protocol with 1 microg each of peanut, English walnut, or Brazil nut protein extracts in alum first at birth and then after modified live virus vaccinations at 3, 7, and 11 weeks of age. The dogs were sensitized to other allergens, including soy and either wheat or barley. Intradermal skin tests, IgE immunoblotting to nut proteins, and oral challenges were performed with ground nut preparations. RESULTS: At 6 months of age, the dogs' intradermal skin test responses were positive to the nut extracts. IgE immunoblotting to peanut, walnut, and Brazil nut showed strong recognition of proteins in the aqueous preparations. Each of the 4 peanut- and the 3 Brazil nut-sensitized dogs and 3 of the 4 walnut-sensitized dogs reacted on oral challenge with the corresponding primary immunogen at age 2 years. None of the peanut-sensitized dogs reacted clinically with walnut or Brazil nut challenges. One of the walnut-sensitized dogs had delayed (overnight) vomiting to Brazil nut. CONCLUSIONS: On the basis of measurements of the mean amount of allergen eliciting a skin test response in dogs, the hierarchy of reactivity by skin testing is similar to the clinical experience in human subjects (peanut > tree nuts > wheat > soy > barley). Cross-reactivity, which was not apparent between soy and peanut or tree nuts or between peanut and tree nuts, was slight between walnut and Brazil nut. The results give further support to the dog as a model of human food allergy.

Animals↗
PubMed2002

Aspergillus on tree nuts: incidence and associations.

California exports tree nuts to countries where they face stringent standards for aflatoxin contamination. Trade concerns have stimulated efforts to eliminate aflatoxins and Aspergillus flavus from almonds, pistachios and walnuts. Incidence of fungi on tree nuts and associations among fungi on tree nuts were studied. Eleven hundred pistachios, almonds, walnuts and brazil nuts without visible insect damage were plated on salt agar and observed for growth of fungi. Samples came both from California nut orchards and from supermarkets. To distinguish internal fungal colonization of nuts from superficial colonization, half the nuts were surface-sterilized before plating. The most common genera found were Aspergillus, Rhizopus and Penicillium. Each species of nut had a distinct mycoflora. Populations of most fungi were reduced by surface sterilization in all except brazil nuts, suggesting that they were present as superficial inoculum on (rather than in) the nuts. In general, strongly positive associations were observed among species of Aspergillus; nuts infected by one species were likely to be colonized by other species as well. Presence of Penicillium was negatively associated with A. niger and Rhizopus in some cases. Results suggest that harvest or postharvest handling has a major influence on nut mycoflora, and that nuts with fungi are usually colonized by several fungi rather than by single species.

Aspergillus flavus↗
PubMed1999

Nut consumption and risk of coronary heart disease: a review of epidemiologic evidence.

Traditionally nuts have been perceived as an unhealthy food because of their high fat content. However, recent accumulative evidence suggests that frequent consumption of nuts may be protective against coronary heart disease (CHD). So far, five large prospective cohort studies (the Adventist Health Study, the Iowa Women Health Study, the Nurses' Health Study, the Physicians' Health Study, and the CARE Study) have examined the relation between nut consumption and the risk of CHD and all have found an inverse association. In addition, several clinical studies have observed beneficial effects of diets high in nuts (including walnuts, peanuts, almonds, and other nuts) on blood lipids. The beneficial effects of nut consumption observed in clinical and epidemiologic studies underscore the importance of distinguishing different types of fat. Most fats in nuts are mono- and polyunsaturated fats that lower low-density lipoprotein cholesterol level. Based on the data from the Nurses' Health Study, we estimated that substitution of the fat from 1 ounce of nuts for equivalent energy from carbohydrate in an average diet was associated with a 30% reduction in CHD risk and the substitution of nut fat for saturated fat was associated with 45% reduction in risk. Given the strong scientific evidence for the beneficial effects of nuts, it seems justifiable to move nuts to a more prominent place in the United States Department of Agriculture Food Guide Pyramid. Regular nut consumption can be recommended in the context of a healthy and balanced diet.

Adult↗
PubMed2003

Interpretation of tests for nut allergy in one thousand patients, in relation to allergy or tolerance.

BACKGROUND: Peanut and tree nut allergy are common, increasing in prevalence and the commonest food cause of anaphylaxis. In the USA, 7.8% are sensitized (have nut-specific IgE), but not all those sensitized are allergic. Lack of data makes interpretation of tests for nut-specific IgE difficult. OBJECTIVES: This is the first study to investigate the clinical significance of test results for peanut and tree nut allergy in allergic or tolerant patients. Findings are related to the severity of the allergy. METHOD: An observational study of 1000 children and adults allergic to at least one nut. History of reactions (severity graded) or tolerance to up to five nuts was obtained and skin prick test (SPT)/serum-specific IgE (CAP) performed. RESULTS: There was no correlation between SPT size and graded severity of worst reaction for all nuts combined or for peanut, hazelnut, almond and walnut. For CAP, there was no correlation for all nuts. Where patients tolerated a nut, 43% had positive SPT of 3-7 mm and 3% > or = 8 mm. For CAP, 35% were positive (0.35-14.99 kU/L) and 5% > or = 15 kU/L. In SPT range 3-7 mm, 54% were allergic and 46% were tolerant. There was poor concordance between SPT and CAP (66%). Of patients with a clear nut-allergic history, only 0.5% had negative SPT, but 22% negative CAP. CONCLUSIONS: Magnitude of SPT or CAP does not predict clinical severity, with no difference between minor urticaria and anaphylaxis. SPT is more reliable than CAP in confirming allergy. Forty-six per cent of those tolerant to a nut have positive tests > or = 3 mm (sensitized but not allergic). One cannot predict clinical reactivity from results in a wide 'grey area' of SPT 3-7 mm; 22% of negative CAPs are falsely reassuring and 40% of positive CAPs are misleading. This emphasizes the importance of the history. Understanding this is essential for accurate diagnosis. Patients with SPT > or = 8 mm and CAP > or = 15 kU/L were rarely tolerant so these levels are almost always (in > or = 95%) diagnostic.

Adolescent↗
PubMed2004

How does stone-tool use emerge? Introduction of stones and nuts to naive chimpanzees in captivity.

Nut-cracking behavior has been reported in several communities in West Africa but not in East and Central Africa. Furthermore, even within nut-cracking communities, there are individuals who do not acquire the skill. The present study aimed to clarify the cognitive capability required for nut-cracking behavior and the process through which the the nut-cracking behavior emerges. To examine emergence, we provided three naive adult chimpanzees with a single opportunity to observe human models. A human tester demonstrated nut-cracking behavior using a pair of stones and then supplied stones and nuts to the chimpanzee subjects. Two out of three chimpanzees proceeded to hit a nut on an anvil stone using a hammer stone, one of whom succeeded in cracking open the nuts during the first test session. The third chimpanzee failed to crack open nuts. We used four variables (object, location, body part used, and action) to describe stone/nut manipulation in order to analyze further the patterns of object manipulation exhibited by the subjects. The analysis revealed that there were three main difficulties associated with nut-cracking behavior. (1) The chimpanzee who failed at the task never showed hitting action. (2) The chimpanzee who failed at the task manipulated nuts but rarely stones. (3) The combination of three objects was not commonly observed in the three chimpanzees. We also discuss our results with reference to the effect of enculturation in captivity and the social context of learning in the wild.

Animals↗
PubMed1994

Bioactivity of selenium from Brazil nut for cancer prevention and selenoenzyme maintenance.

Brazil nut (Bertholletia excelsa) is one of very few consumable products with exceptionally high levels of selenium. The mean selenium concentrations of two shipments of Brazil nut used in the present study were determined to be 16 and 30 micrograms/g. In contrast, most common foods contain much less selenium, from 0.01 to 1 micrograms/g. Previous research on selenium cancer chemoprevention invariably used a pure compound, whereas little information is available on the efficacy of selenium delivered naturally in a food form. This paper reports the results of two mammary cancer prevention experiments in the rat dimethylbenz[a]anthracene model by continuous feeding of selenium-rich Brazil nut (processed to a smooth-textured nut material for mixing in the diet). A dose-dependent inhibitory response was observed at dietary selenium concentrations of 1-3 micrograms/g. Interestingly, Brazil nut was found to be just as powerful as sodium selenite, if not more so, at similar levels of dietary selenium intake. Mammary cancer protection gland, and plasma. The magnitude of tissue selenium accumulation was proportional to the amount of Brazil nut added to the diet. The nutritional biopotency of selenium in Brazil nut was also evaluated by the repletion of two selenoenzymes, glutathione peroxidase and type I 5'-deiodinase, in selenium-deficient rats. Supplementation with Brazil nut as the sole source of selenium produced an efficient gradient of enzyme restoration at 0.05-0.2 microgram/g of dietary selenium. A parallel comparison with sodium selenite indicated that the selenium in Brazil nut and selenite selenium were equally bioactive. Although at this point it can only be inferred that the above biologic effects are likely to be attributable to the high selenium content of Brazil nut, there is persuasive evidence to suggest that the models under investigation are responding to the selenium rather than to the other components of Brazil nut.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2003

Nut consumption and body weight.

Frequent nut consumption is associated with lower rates of coronary artery disease (CAD). Also, nut-rich diets improve the serum lipid profile of participants in dietary intervention trials. However, nuts are fatty foods, and in theory their regular consumption may lead to body weight gain. Because obesity is a major public health problem and a risk factor for CAD, clinicians and policy makers ponder several questions. Will hypercholesterolemic patients advised to consume nuts gain weight? Is recommending increased nut consumption to the general population for CAD prevention sound public health advice? Epidemiologic studies indicate an inverse association between frequency of nut consumption and body mass index. In well-controlled nut-feeding trials, no changes in body weight were observed. Some studies on free-living subjects in which no constraints on body weight are imposed show a nonsignificant tendency to lower weight while subjects are on the nut diets. In another line of evidence, preliminary data indicate that subjects on nut-rich diets excrete more fat in stools. Further research is needed to study the effects of nut consumption on energy balance and body weight. In the meantime, the available cumulative data do not indicate that free-living people on self-selected diets including nuts frequently have a higher body mass index or a tendency to gain weight.

Adolescent↗
PubMed2005

Microbiological and aflatoxin evaluation of Brazil nut pods and the effects of unit processing operations.

Harvesting of Brazil nuts not only helps to preserve the Amazon rainforest but also provides income to individuals who would otherwise have little means of making a livelihood. Recently, the European Community has tightened the quality requirements for Brazil nuts, particularly with regard to aflatoxin levels and microbiological contamination. The objectives of this research were to gain a better understanding of the origin of aflatoxins on Brazil nuts and to microbiologically evaluate some of the operations involved in processing. In this regard, five Brazil nut pods were aseptically picked from trees located in each of three concessions of the Peruvian Amazon rainforest (Madre de Dios province). The exteriors of the pods and the nuts were examined for yeast and molds, including Aspergillus flavus and Aspergillus parasiticus, and for bacteria, including Salmonella and Escherichia coli. Brazil nuts obtained from various commercial process operations located in Peru were similarly evaluated. Exteriors of all Brazil nut pods did not contain A. parasiticus, and only pods from one concession yielded A. flavus isolates. All isolates tested were aflatoxigenic (630 to 915 ppb total aflatoxin). Coliforms, E. coli, and salmonellae were not recovered from any of the pods. Whole, in-shell nuts obtained after opening the pods yielded no A. flavus or A. parasiticus. Aflatoxins were not detected (detection limit 1.75 ppb) in any of the nuts. Whole, in-shell and shelled nuts from various process operations were all positive for A. flavus but negative for E. coli and salmonellae. Soaking of whole, in-shell nuts before cracking or shelling increased coliform numbers, whereas levels of A. flavus decreased. In order to gain a better understanding of the sanitary performance of the unit process operations, additional evaluations should be conducted on product lots processed on different days. Also, the microbiology of product processed from common lots should be followed through the various unit operations and compared.

Aflatoxins↗
PubMed2004

Betel nut chewing: the prevalence and the intergenerational effect of parental behavior on adolescent students.

PURPOSE: To explore the betel nut chewing prevalence among students, analyze the probability and the odds ratio of ex-chewers and current chewers, as well as the correlation between parental behavior characteristics and those of adolescents chewing betel nut. METHODS: A cross-sectional survey was designed and 10,288 Taiwanese students answered the questionnaires in 2002. A structured questionnaire included information about betel nut chewing behavior among the adolescent students, sociodemographic data, and the betel nut chewing practice among parents or classmates. Samples were randomly chosen from each cluster of different types of schools in various areas. Three different grade levels of the first, second, and third grade (ages 16-18 years) were selected. Frequency distribution was used to analyze the prevalence among adolescent students, and Chi-square tests were used to compare the differences of betel nut chewing behavior among genders and the effect of parental behavior and socioeconomic factors. Logistic regression was used to analyze the odds ratio of the prevalence of adolescent students' betel nut chewing in the different types of schools and by gender. RESULTS: When the parents' marriage was not successful, or was of a lower social status, a higher incidence of adolescent betel nut chewing was observed. It was easy to experience betel nut chewing in adolescence if either parent chewed betel nut. The prevalence of betel nut chewing among male students was higher than female students and among vocational school students than general school students. The odds ratio of agricultural school students to general school students was highest of all the ex-chewers and current chewers from different types of schools. CONCLUSIONS: Betel nut chewing behavior is related to the effect of parental behavior on adolescent students. Apparently, it is indicated that there is a significant intergenerational effect of the parent's behavior on their children's behavior.

Adolescent↗
PubMed2003

Betel nut chewing and related factors in adolescent students in Taiwan.

OBJECTIVE: To investigate the prevalence of betel nut chewing and related factors among adolescent students in general, manufacturing, commercial, agricultural and medical technology schools in Taiwan. To make suggestions regarding how health authorities can reduce the number of students taking up the habit. MATERIALS AND METHODS: A cross-sectional survey was designed, and 10,288 students answered the questionnaire. RESULTS: Significantly more male than female students were betel nut chewers. The less urbanized areas were also associated with a higher prevalence of the habit. The prevalence of the habit grew with increasing age. By analysing betel nut chewing behaviour, it was found that most students started chewing betel nuts because of curiosity, and most obtained betel nuts from their friends and classmates. Betel nut chewing behaviour is definitely related to peer pressure. Most betel nut chewers did not realize that withdrawal could lead to physiological reactions, and they were ignorant of any risk to health even though they were compulsive betel nut chewers. The health-harming behaviours of both smoking and drinking were found in many betel nut chewers, particularly smoking. CONCLUSION: This study confirmed the need for a health education programme dealing with the health risks of betel nut chewing for students at risk. The health authorities could also develop a programme for betel nut chewing among Taiwan's adolescent students, emphasizing the dangers of this habit.

Adolescent↗
PubMed2004

A population-based study of the association between areca nut chewing and type 2 diabetes mellitus in men (Keelung Community-based Integrated Screening programme No. 2).

AIMS/HYPOTHESIS: The aim of this study was to assess whether the diabetogenicity of areca nut (Areca catechu or 'betel-nut'), which has previously been demonstrated experimentally in mice, independently contributes to the risk of hyperglycaemia or type 2 diabetes in men in Taiwan, where the habit has become established relatively recently. METHODS: We used data from a population-based cross-sectional survey and a multiple-disease-screening programme that tested for hyperglycaemia, type 2 diabetes and risk factors related to type 2 diabetes. Data on habitual areca nut chewing were available for 14,816 men. Multiple logistic regression models were used to determine whether areca nut chewing was an independent risk factor for type 2 diabetes. RESULTS: Compared with non-chewers, areca nut chewers had higher age-adjusted prevalence rates for hyperglycaemia (11.4% vs 8.7%) and type 2 diabetes (10.3% vs 7.8%). Areca nut chewing independently increased the risk of hyperglycaemia (adjusted odds ratio [OR] 1.19, 95% CI 0.97-1.45) and type 2 diabetes (adjusted OR 1.29, 95% CI 1.04-1.60). The independent effects of duration of chewing were dose-dependent for type 2 diabetes (adjusted OR 1.32 for the duration of 10-19 years and 1.41 for the duration of > or =20 years), as were the effects of increased rates of areca nut chewing (adjusted OR 1.14 for <10 pieces/day, 1.30 for 10-19 pieces/day and 2.02 for > or =20 pieces/day); similar findings were noted for hyperglycaemia. CONCLUSIONS/INTERPRETATION: The habit of chewing areca nut independently contributes to the risk of both hyperglycaemia and type 2 diabetes in Taiwanese men. This association is dose-dependent with respect to the duration of areca nut use and the quantity of areca nut chewed per day.

Adult↗
PubMed1976

Detection of allergy to nuts by the radioallergosorbent test.

The diagnosis of food allergy is often difficult to make by conventional means. Histories are frequently ambiguous, and skin testing is of dubious reliability because of the number of false-positive and false-negative reactions. We have evaluated the radioallergosorbent test (RAST) for the in vitro measurement of the specific IgE antibodies to nuts, including Brazil nut, almond, walnut, pecan, cashew, and the legume, peanut. Serums were obtained from 18 patients with a history of nut allergy and IgE level and specific IgE antibodies were measured. Thirteen of the 18 patients had significantly elevated IgE antibody (greater than twice control) to one or more of the allergens. Prausnitz-Küstner tests on selected serums in general corroborated the results of the in vitro studies. Five patients had RAST elevations to 2 or more nuts. As a group RAST-positive patients had elevated mean serum IgE levels and more severe clinical symptoms (p less than 0.01). The specificity and cross-reactivity of IgE antibodies to different nut antigens was investigated by RAST inhibition with serums from 5 patients having high levels of IgE antibody. In 4 patients no cross-reactivity between Brazil nut and peanut was found. In contrast, several nut extracts inhibited the reaction of pecan allergen with IgE antibodies. These results indicate that specific IgE antibodies can be measured by RAST in patients with nut allergy and the cross-reactivity of nut antigens can be investigated. RAST would appear to be most useful in confirming the diagnosis of nut hypersensitivity in children or in highly allergic patients in whom skin testing poses a risk of anaphylaxis.

Absorption↗
PubMed2005

Cholesterol lowering effects of nuts compared with a Canola oil enriched cereal of similar fat composition.

BACKGROUND AND AIM: Small quantities of nuts protect against subsequent cardiovascular risk. There is speculation that the cholesterol lowering effect associated with nut consumption arises primarily from the fatty acid composition of nuts but may be caused by some other component. To evaluate this possibility we compared the effect of various nuts, against a Canola oil based cereal with a comparable fatty acid profile, on lipids, lipoproteins and fatty acids to determine whether the fatty acid profile of nuts explains their cholesterol lowering effects. METHODS AND RESULTS: Twenty-eight men and women with mean (s.d.) levels of total and low density lipoprotein cholesterol of 6.0 (1.1) mmol/L, and 4.1 (1.0) mmol/L, respectively and a mean body mass index (BMI) of 26.9 (3.2) kg/m2 took part in a randomised cross over trial. For two periods of six weeks, separated by a four-week washout, participants were asked to consume a low saturated fat diet, which included either 30 g/d nuts (nut diet) or one serving of a cereal containing Canola oil (cereal diet). There were no significant differences in the lipids, lipoproteins, plasma fatty acids or other variables between the two diets at the end of the study. Total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) were lower on both experimental diets than at baseline, 0.51 mmol/L and 0.40 mmol/L (p<0.001, p<0.01), respectively on the nut diet and 0.42 mmol/L and 0.37 mmol/L (p<0.001, p<0.01), respectively on the cereal diet. CONCLUSION: A 30 g serving of nuts, or a serving of a Canola oil enriched cereal with a similar fatty acid composition reduced total and LDL cholesterol to a similar extent when consumed as part of a lipid lowering diet. Results suggest that foods with a similar fatty acid composition to nuts can produce comparable decreases in lipoprotein mediated cardiovascular risk.

Cholesterol↗
PubMed1996

Identification of a Brazil-nut allergen in transgenic soybeans.

BACKGROUND: The nutritional quality of soybeans (Glycine max) is compromised by a relative deficiency of methionine in the protein fraction of the seeds. To improve the nutritional quality, methionine-rich 2S albumin from the Brazil nut (Betholletia excelsa) has been introduced into transgenic soybeans. Since the Brazil nut is a known allergenic food, we assessed the allergenicity of the 2S albumin. METHODS: The ability of proteins in transgenic and non-transgenic soybeans, Brazil nuts, and purified 2S albumin to bind to IgE in serum from subjects allergic to Brazil nuts was determined by radioallergosorbent tests (4 subjects) and sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (9 subjects) with immunoblotting and autoradiography. Three subjects also underwent skin-prick testing with extracts of soybean, transgenic soybean, and Brazil nut. RESULTS: On radioallergosorbent testing of pooled serum from four subjects allergic to Brazil nuts, protein extracts of transgenic soybean inhibited binding of IgE to Brazil-nut proteins. On immunoblotting, serum IgE from eight of nine subjects bound to purified 2S albumin from the Brazil nut and the transgenic soybean. On skin-prick testing, three subjects had positive reactions to extracts of Brazil nut and transgenic soybean and negative reactions to soybean extract. CONCLUSIONS: The 2S albumin is probably a major Brazil-nut allergen, and the transgenic soybeans analyzed in this study contain this protein. Our study show that an allergen from a food known to be allergenic can be transferred into another food by genetic engineering.

2S Albumins, Plant↗