Anaphylaxis due to Brazil nut skin testing in a walnut-allergic subject.

The diagnosis and management of nut allergy can be difficult because of the possible severity of the clinical manifestations and the cross reactivity between different species. We report a case of anaphylaxis due to skin testing in a young adult with clinically ascertained walnut allergy. After an episode of anaphylaxis due to walnut ingestion, a routine diagnostic workup was carried out, involving skin prick test with commercial extracts, prick by prick with fresh food and CAP-RAST assay for different nuts. Immediately after pricking with fresh Brazil nut, a severe episode of anaphylaxis occurred, that required epinephrine and intravenous steroids. The subject had never eaten Brazil nut before. Therefore we hypothesize a cross reactivity effect, since this phenomenon is well known for tree nuts. Our case suggests that in vivo diagnosis, especially if fresh nuts are used, should be performed only if adequate equipment to treat anaphylaxis is available.     

Anaphylaxis to pine nut: cross-reactivity to Artemisia vulgaris?

The use of pine nuts, the seeds of Pinus pinea, is on the increasing in the modern Mediterranean diet. Little more than 20 cases of allergy to this tree nut have been published, and cross-reactivity with pine pollen, peanut and almond has already been reported. We describe the case of a young boy with several episodes of anaphylaxis after pine nut ingestion. Specific IgE to pine nut and Artemisia vulgaris was demonstrated by skin prick tests and in vitro determination of specific IgE, although no IgE to pine pollen or other nuts was detected. Immunoblotting of Artemisia vulgaris and pine nut revealed two matching diffuse bands, just below 14 kDa and 30 kDa. The ImmunoCAP inhibition assays showed complete inhibition of pine nut specific IgE after serum incubation with Artemisia vulgaris extract. As far as we know, this is the first reported case of documented cross-reactivity between pine nut and Artemisia vulgaris.     

Anaphylaxis to pine nuts and immunological cross-reactivity with pine pollen proteins.

Despite the wide use of pine nuts, the fruit of Pinus pinea, only a few reports of allergic reactions to them have been published. We present herein a case of food allergy to pine nuts in a patient who showed no clinical symptoms to pine pollen despite the presence in her serum of specific IgE antibodies. In order to verify whether the reaction against pine nuts was IgE mediated, specific IgE against pine nuts and pollen were evaluated by skin-prick test, prick by prick and RAST. Immunoblotting and immunoblotting-inhibition were used to evaluate the allergenic components of both extracts and their cross-reactivity. Prick by prick with fresh pine nuts and RAST with pine nut and pine pollen extracts showed that the patient had high levels of specific IgE against both extracts. Immunoblotting experiments showed the presence in serum of IgE antibodies against several components in pine nuts and pollen. Immunoblotting-inhibition experiments demonstrated the presence of some cross-reacting components. These data confirm the existence of food allergy induced by pine nuts. This sensitization to pine nuts developed with no symptoms of pine pollinosis. Development of pollinosis may require a longer time of exposure to allergens. Based on the cross-reactivity between pine nut and pine pollen extracts, cosensitization to these two allergens could be possible.     

Nut consumption and decreased risk of sudden cardiac death in the Physicians' Health Study

BACKGROUND: Dietary nut intake has been associated with a reduced risk of coronary heart disease mortality; however, the mechanism is unclear. Since components of nuts may have antiarrhythmic properties, part of the benefit may be due to a reduction in sudden cardiac death. METHODS: We prospectively assessed whether increasing frequency of nut consumption, as ascertained by an abbreviated food frequency questionnaire at 12 months of follow-up, was associated with a lower risk of sudden cardiac death and other coronary heart disease end points among 21 454 male participants enrolled in the US Physicians' Health Study. Participants were followed up for an average of 17 years. RESULTS: Dietary nut intake was associated with a significantly reduced risk of sudden cardiac death after controlling for known cardiac risk factors and other dietary habits (P for trend,.01). Compared with men who rarely or never consumed nuts, those who consumed nuts 2 or more times per week had reduced risks of sudden cardiac death (relative risk, 0.53; 95% confidence interval, 0.30-0.92) and total coronary heart disease death (relative risk, 0.70; 95% confidence interval, 0.50-0.98). In contrast, nut intake was not associated with significantly reduced risks of nonsudden coronary heart disease death or nonfatal myocardial infarction. CONCLUSION: These prospective data in US male physicians suggest that the inverse association between nut consumption and total coronary heart disease death is primarily due to a reduction in the risk of sudden cardiac death.     

Pistachio Allergy-Prevalence and In vitro Cross-Reactivity with Other Nuts

BackgroundTree nut allergy is characterized by a high frequency of life-threatening reactions and is typically lifelong persistent. Some people with a pistachio nut allergy, which is common in the pistachio rich area of Iran, develop a hypersensitivity to other tree nuts as well. The aim of this study was to investigate the prevalence of pistachio nut allergy in Iran, the major pistachio cultivation region in the world. The study also addressed the presence of allergenic cross-reactivity between pistachio and other nuts, including almond, peanut, and cashew in pistachio allergic patients.MethodsA survey was conducted to determine whether the prevalence of pistachio allergy is affected by exposure to this nut in pistachio cultivation regions, as well as possible cross-reactivity between pistachio and other nuts including cashew, almond, and peanut. Inhibition Western blot and inhibition ELISA studies were conducted to assess the presence of allergenic cross-reactivity between pistachio and the other tree nuts.ResultsOur results revealed that the prevalence of pistachio allergy is twice as much in pistachio cultivation regions than other areas. Western blotting and inhibition ELISA presented high percentages of inhibition with pistachio and cashew, followed by almond and, to some degree, peanut which indicates different levels of aller- genic cross-reactivity.ConclusionsThe results indicate that exposure of people to pistachio significantly affects the prevalence of its allergic reactions. In addition, it was observed that, among pistachio allergic subjects, such exposure may affect the co-sensitivities with other nuts, including cashew and almond. The plant taxonomic classification of pistachio and other tree nuts does appear to predict allergenic cross-reactivity.     

Tree nut allergy

Tree nuts are clinically associated with severe immunoglobulin E-mediated systemic allergic reactions independent of pollen allergy and with reactions that are usually confined to the oral mucosa in patients with immunoglobulin E directed toward cross-reacting pollen allergens. The latter reactions can progress to severe and life-threatening episodes in some patients. Many patients with severe tree nut allergy are co-sensitized to peanut. Clinical studies on cross-reactivity between the tree nuts are few in number, but based on reports to date, avoidance of the other tree nuts once sensitivity is diagnosed appears prudent unless specific challenges are performed to ensure clinical tolerance. Even then, great care must be taken to avoid crosscontamination. As with other severe food allergies, a recurrent problem in clinical management is the failure of physicians to prescribe self-injectable epinephrine to patients who are at risk of anaphylaxis.     

Allergie alimentaire à la noix du Brésil : à propos de cinq cas chez l’enfant d’âge préscolaire

Five cases of allergy to Brazil nuts are reported in children under 6 years of age. All patients have other atopic diseases and reacted in a few minutes. Sensitivity to other nuts and peanuts is investigated. With a history of allergy to any nuts, a patient should always be tested for the other nuts.     

Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Women's Health Study

BACKGROUND AND AIM: Recent epidemiological studies suggest that there is an inverse association between the frequent consumption of nuts and the risk of coronary heart disease (CHD), and clinical investigations suggest that diets high in nuts may reduce serum cholesterol levels. This study assessed whether the risk of death due to CHD and all causes is reduced in postmenopausal women who frequently consume nuts. METHODS AND RESULTS: In 1986, 34,111 postmenopausal women with no known cardiovascular disease reported the frequency of their consumption of nuts and other foods, as well as other CHD risk factors. During approximately 12 years of follow-up, 3726 women died, 657 from CHD. After adjustment for multiple risk factors for CHD and dietary variables, there was an inverse but not statistically significant association between frequent nut consumption (two or more 28.5 g servings per week compared with less than one serving per month) and death from CHD (relative risk 0.81; 95% confidence interval: 0.60-1.11). There was also a weak inverse association between frequent nut intake and all-cause mortality (relative risk 0.88; 95% confidence interval: 0.77-0.99, p for trend = 0.047). CONCLUSIONS: Frequent nut consumption may offer postmenopausal women modest protection against the risk of death from all causes and CHD.     

The relationship between nut consumption and blood pressure in an Iranian adult population: Isfahan Healthy Heart Program

Background and aimsFew studies outside of Western countries have evaluated the relationship between consumption of nuts and blood pressure (BP). This study aimed to investigate the relationship between nut consumption and blood pressure in an Iranian adult population.Methods and resultsWe performed a cross-sectional investigation among 9660 randomly selected Iranian adults, sampled to represent three large Iranian regions, using data collected in the Isfahan Healthy Heart Program in 2007. The frequency of nut consumption was assessed by a food frequency questionnaire. Systolic and diastolic BPs (SBP and DBP) were measured in duplicate by trained personnel using a standard protocol. Multiple linear and logistic regressions were applied to assess the relationship between nut intake and BP levels and the presence of hypertension as SBP ≥ 140 mmHg, and/or a DBP ≥ 90 mmHg and/or current use of at least one type of anti-hypertensive medication. Those with nut consumption ≥4 times/week showed less mean of BPs and hypertension prevalence, compared to those who consumed nuts <1 times/week (p < 0.001). Compared to no consumption, consuming nuts ≥4 times/week was associated with a 34% lower prevalence of hypertension (multivariate odds ratio (OR) = 0.66; confidence interval (CI) = 0.51–0.87; p for trend = 0.009).ConclusionsMore frequent nut consumption is associated with lower BP and lower risk of hypertension among Iranian adults.     

Les allergènes de l’arachide et des fruits à coque

The foods contain several hundreds of proteins for which only a small number, called allergens, is responsible for allergic reactions. The edible tree nuts (almond, walnut, cashew, Brazil nut, macadamia nut, pecan, Nangai nut, pistachio, pine nut, chestnut and coconut) consist of approximately, 15% of proteins. The objective of this review is to present, from a biochemical point of view, the allergens of these nuts known at the present time and to discuss what this type of information can bring in the comprehension of the mechanisms of cross reaction.     

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.     

Association of nut consumption with CVD risk factors in young to middle-aged adults: The Coronary Artery Risk Development in Young Adults (CARDIA) study

Background and aimsFew studies have examined long-term associations of walnut, other nut, and no nut consumption with cardiovascular disease (CVD) risk factors. Results from prospective studies with long-term follow-up can provide further evidence for dietary guideline messaging to consume nuts. Therefore, we examined the associations of walnut, other nut, and no nut consumption with diet quality and CVD risk factors over 30 years of follow-up.Methods and resultsData were analyzed from 3092 young adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary intake, including walnuts and other nuts, was assessed 3 times over 20 years. CVD risk factors were measured at multiple exams. General linear regression evaluated the associations of walnut, other nut, and no nut consumption with CVD risk factors over 30 years (Y30) of follow-up. The 20-year cumulative mean intake of walnuts (0.74 oz/d), other nuts (1.6 oz/d), or no nut consumption was differentially associated with HEI-2015 and CVD risk factors by Y30. Generally, walnut consumers had significantly higher HEI-2015, lower body mass index, waist circumference, blood pressure, and triglyceride concentration, and gained less weight since baseline than other nut consumers (p ≤ 0.05 for all). Further, walnut consumers had lower fasting blood glucose than no nut consumers (p ≤ 0.05).ConclusionStudy findings that walnut and other nut consumption was associated with better CVD risk factors and diet quality aligns with the 2020–2025 US. Dietary Guidelines for Americans recommendation to consume nuts, such as walnuts, within the context of a healthy diet.     

Arachide,fruits secs oléagineux : réalité clinique,conséquences sociales

The frequency of allergic reactions to peanut and tree nuts has increased. The cumulated prevalence of peanut allergy is high, 0.5 to 1.2% in American and Western European children; the prevalence of tree nut allergy is 0.5%. Allergic reactions to peanut and tree nuts can be life threatening. This problem is widely discussed in the media. Sensitization to tree nuts should be investigated in children with allergy to peanut or to any other nut. Evaluation  of the patient must take into account the clinical data and the results of skin tests, specific IgE assays and labial provocation tests. The decision of whether to perform a provocation challenge should be individualized. Children, particularly adolescents, at risk for severe reactions include those with multiple allergies, asthma, especially uncontrolled asthma, or facilitating factors such as drugs (including aspirin), alcohol and exercice. At present, prevention calls for avoidance of peanuts and tree nuts. Global management and careful education are essential and should be tailored to each child and its family. Management of severe food allergies must be comprehansive and must consist of more than just epinephrine.     

Effects of mixed nut consumption on LDL cholesterol,lipoprotein(a), and other cardiometabolic risk factors in overweight and obese adults

Background and aimsElevated LDL-C, lipoprotein(a) [Lp(a)], and inflammation are associated with greater risk for atherosclerotic cardiovascular events. Consumption of individual nut types decreases these risk factors but knowledge about the effect of mixed nuts on Lp(a) is limited. The objective of this study was to determine the effects of consuming 42.5 g/day of mixed nuts on LDL-C, Lp(a), and inflammatory markers in individuals with overweight or obesity.Methods and resultsIn a 16-week randomized control trial, 29 participants with overweight or obesity (BMI 25–40 kg/m²) consumed either 42.5 g/day of mixed nuts (cashews, almonds, macadamia nuts, Brazil nuts, pecans, pistachios, walnuts, and peanuts) or 69 g/day isocaloric pretzels. Blood samples were collected at baseline, week 8, and week 16 for analysis on total cholesterol (TC), LDL-C, Lp(a), inflammation markers, glucose, insulin, adiponectin and liver function enzymes. No significant differences were seen in TC, LDL-C, HDL-C, Lp(a), or liver function enzymes between the two groups. Participants consuming mixed nuts had significantly lower body fat percentage and diastolic blood pressure, and higher adiponectin (all P ≤ 0.05). C-reactive protein (CRP) and 8-oxo-deoxyguanosis (8-oxodG) showed non-significant decreasing trends and total antioxidant capacity (TAC) had a non-significant increasing trend in the mixed nut group.ConclusionConsumption of mixed nuts had no evidence of an effect on LDL-C or Lp(a) throughout the intervention. Notably, mixed nut consumption lowered body fat percentage without significant changes in body weight or BMI. Future studies with larger sample sizes investigating the changing trends of CRP, 8-oxodG, and TAC are warranted.Clinical trial registerNCT03375866.     

Poppy seed allergy: a case report and review of the literature.

Seeds of the poppy plant are traditionally used in bakeries, e.g., for garnishing bread or making cakes. Reports of allergic type I sensitivity to poppy seed are rare. According to the literature, severe reactions may occur, affecting mainly patients with allergy to pollens or nuts. We report on a 16-year-old boy who has developed erythema and angioedema, conjunctivitis, and dyspnea due to inhalation of poppy seed. Skin-prick tests were positive for poppy seed, hazelnut, and chickpea. The concentration of specific IgE for poppy seed, hazelnut, and peanut were 3.36 kU/L (class 2), 1.5 kU/L (class 2), and 6.17 kU/L (class 3), respectively. Allergic reactions associated with inhalation of food allergens have been reported for some foods but not for poppy seed. This is the first report on inhalative allergy to the poppy seed. Although poppy seeds are not commonly used, we underline the possible importance of such rare and often hidden sources of allergens, especially in patients with nut allergy.     

Passive transfer of nut allergy after liver transplantation

An anaphylactic reaction to cashew nut developed in a nonatopic 60-year-old man 25 days after receiving a liver allograft from a 15-year-old atopic boy who died of anaphylaxis after peanut ingestion. The liver recipient had no history of nut allergy. Posttransplantation skin prick test results were positive for peanut, cashew nut, and sesame seed, and the donor had allergen-specific IgE antibodies to the same 3 allergens. Contact tracing of the recipients of other solid organs from the same donor disclosed no other development of allergic symptoms after ingestion of peanut or cashew nut. Results of molecular HLA typing did not detect any donor-origin leukocytes in the recipient after transplantation, which excluded peripheral microchimerism. The patient inadvertently ingested peanut-contaminated food and suffered a second anaphylactic reaction 32 weeks after the transplantation. This case illustrates that transfer of IgE-mediated hypersensitivity can occur after liver transplantation and have potentially serious consequences. We therefore recommend that organ donors undergo screening for allergies, and that recipients be advised regarding allergen avoidance.     

Nut consumption and incidence of hypertension: The SUN prospective cohort

Background and aimsThe consumption of tree nuts could reduce the risk of hypertension, but scarce research has been done to evaluate this potential association. We assessed the association between nut consumption and the incidence of hypertension among 9919 Spanish university graduates followed-up biennially for a median of 4.3 years.Methods and resultsFood habits were assessed with a validated 136-item food-frequency questionnaire. Nut consumption was classified into four categories: rarely/never, 1–3/month, 1/week, and 2+/week. A participant was classified as an incident case of hypertension when, being free of hypertension at baseline, he/she subsequently reported a physician-made diagnosis of hypertension in at least one of the follow-up questionnaires. The incidence of hypertension was 12.4 per 1000 person-years. We found no association between nut consumption and incidence of hypertension after adjusting for sex, age and other dietary and non-dietary potential confounders (hazard ratio [HR] for those in the highest vs. lowest nut consumption category = 0.77 [IC 95%: 0.46–1.30] p = 0.795). Results were not modified when we stratified them analyses according to sex or to body mass index.ConclusionOur data do not provide evidence for an inverse association between nut consumption and incident hypertension in our cohort. Further results from cohorts and trials with a higher baseline risk of hypertension should be obtained to test this relationship.     

Nuts and Cardiovascular Disease Prevention

Purpose of Review

We review recent epidemiological and clinical studies investigating the consumption of tree nuts and peanuts and cardiovascular disease (CVD) mortality as well as CVD risk factors.

Recent Findings

A greater consumption of tree nuts and peanuts is associated with a reduced risk of CVD mortality, as well as lower CVD events. Furthermore, risk factors associated with the development of CVD such as dyslipidemia, impaired vascular function, and hypertension are improved with regular tree nut and peanut consumption through a range of mechanism associated with their nutrient-rich profiles. There is weak inconsistent evidence for an effect of nut consumption on inflammation. There is emerging evidence that consuming tree nuts reduces the incidence of non-alcoholic fatty liver disease (NAFLD) and promotes diversity of gut microbiota, which in turn may improve CVD outcomes.

Summary

Evidence for CVD prevention is strong for some varieties of tree nuts, particularly walnuts, and length of supplementation and dose are important factors for consideration with recommendations.

     

The association between left ventricular hypertrophy and consumption of nuts,including peanuts,pine nuts,and almonds

Background and aimsStudies have reported that nut consumption is potentially beneficial in preventing cardiovascular disease. However, data are insufficient regarding the association between nut consumption and left ventricular hypertrophy (LVH).Methods and resultsIn the Kangbuk Samsung Health Study, the participants were 34,617 men and 12,257 women who completed a food-frequency questionnaire for nut consumption and received echocardiography. Nut consumption was evaluated only for peanuts, pine nuts, and almonds defining 15 g as one serving/servings dose. Multivariable adjusted odds ratio (OR) and 95% confidence interval (CI) for LVH were evaluated according to the consumption frequency of one serving dose of nut. The frequency of nut consumption was categorized into five groups (<1/month, 1/month–1/week, 1–2/week, 2–4/week, and ≥4/week). The subgroup analysis was conducted by dividing the participants into the following two groups: the nonhypertensive/nondiabetic group and hypertensive or diabetic group.In women, nut consumption ≥2/week had the lower multivariable adjusted OR and 95% CI for LVH (2–4/week: 0.46 [0.26–0.81] and ≥4/week: 0.48 [0.25–0.92]) when compared with nut consumption <1/month. This association was identically observed in the subgroup analysis for women without hypertension and diabetes mellitus (DM) and women with hypertension or DM. However, men did not show the significant association.ConclusionIn women, nut consumption ≥2/week was associated with the decreased probability of LVH. Further research studies should investigate whether the beneficial effect of nut consumption on LV structure results in better cardiovascular prognosis.     

Allergy to Anacardiaceae: description of cashew and pistachio nut allergens.

Some members of the Anacardiaceae family, such as cashew nut, pistachio nut and mango, have been reported to cause immediate allergic reactions. We report three cases of anaphylaxis to cashew nuts. With the aim of describing the allergens existing in cashew and pistachio nuts, patients were prick tested with cashew and pistachio extracts. Specific IgE against both nuts was studied by CAP and SDS-PAGE/immunoblotting. It was found that skin tests and specific IgE to cashew and pistachio nuts were positive in the three patients. Both nuts showed several protein bands in SDS-PAGE. The strongest IgE-binding bands had similar molecular weights (15, 30 and 60 kDa) in cashew and pistachio nuts. These main bands were found to be sensitive to reducing agents. It was concluded that these three patients suffered immediate reactions to cashew nut due to an IgE-mediated mechanism.