Effects of Long-Term Walnut Supplementation on Body Weight in Free-Living Elderly: Results of a Randomized Controlled Trial

Objective: To assess the effects of chronic walnut consumption on body weight and adiposity in elderly individuals. Methods: The Walnuts and Healthy Aging study is a dual-center (Barcelona, Spain and Loma Linda University (LLU)), 2-year randomized parallel trial. This report concerns only the LLU cohort. Healthy elders (mean age 69 year, 67% women) were randomly assigned to walnut (n = 183) or control diets (n = 173). Subjects in the walnut group received packaged walnuts (28–56 g/day), equivalent to ≈15% of daily energy requirements, to incorporate into their habitual diet, while those in the control group abstained from walnuts. Adiposity was measured periodically, and data were adjusted for in-trial changes in self-reported physical activity. Results: After 2 years, body weight significantly decreased (p = 0.031), while body fat significantly increased (p = 0.0001). However, no significant differences were observed between the control and walnut groups regarding body weight (−0.6 kg and −0.4 kg, respectively, p = 0.67) or body fat (+0.9% and +1.3%, respectively, p = 0.53). Lean body mass, waist circumference, and waist-to-hip ratio remained essentially unchanged. Sensitivity analyses were consistent with the findings of primary analysis. Conclusion: Our findings indicate that walnuts can be incorporated into the daily diet of healthy elders without concern for adverse effects on body weight or body composition.

Molecular allergology in practice: an unusual case of LTP allergy

The authors describe an unusual case of LTP allergy. A 35 years old patient presented repeated episodes of angiooedema after food intake and complained 10 years ago of contact urticaria and rhinoconjunctivitis when exposed to cannabis leaves and to marijuana smoke. The suspected responsible foods, such as wheat flour in bread, are known to contain LTR Oral syndrome occurred after ingestion of walnuts. Cutaneous tests confirmed immediate responses to several flours and nuts and also to cannabis leaf and flower. A few months later he had similar accidents following peach ingestion and drinking of beer and several wines which all induced positive skin tests. Serological investigations using ImmunoCAP and ISAC microarray confirmed IgE positivity for n Pru p3, r Cor a 8 and n Art v3. It was assumed that sensitization to LTP, the major allergen of cannabis, was responsible of the primary sensitization and induced further LTP food allergies.

Increased expression of MAIL, a cytokine-associated nuclear protein, in the prodromal stage of black walnut-induced laminitis

REASONS FOR PERFORMING STUDY

The mediators and signalling cascades important in the initiation of laminitis remain unclear. We therefore wanted to explore the genes and overall signalling mechanisms that play an important role in the developmental stage of laminitis.

OBJECTIVE

To use a broad genomic screening technique to identify novel genes that are differentially regulated in the equine lamellae during the developmental period of laminitis.

METHODS

Differential mRNA display (DRD) was performed to discover regulated genes, and real-time quantitative polymerase chain reaction (RT-qPCR) was then used to evaluate lamellar mRNA levels of a regulated gene (MAIL) and mediators related to that gene (IL-1beta and IL-6) in control horses (n = 5) and horses administered black walnut extract (BWE; n = 5).

RESULTS

Using DRD, MAIL was identified as a regulated gene. RT-qPCR indicated a 4-fold increase in expression of the MAIL mRNA in BWE lamellae compared to controls. A 30-fold increase in IL-1beta, and a 160-fold difference in IL-6 mRNA expression was present in BWE lamellae. Differences in MAIL, IL-1beta and IL-6 mRNA expression were statistically significant between groups (P < 0.05).

CONCLUSIONS AND POTENTIAL RELEVANCE

The data strongly support a role for inflammatory cytokines in the developmental stages of laminitis, possibly inducing the vascular and metabolic alterations reported to occur in the affected digit. These results potentially support the use of anti-inflammatory drugs in horses at risk of laminitis, and warrant further investigation of the link between systemic disease processes associated with laminitis and the reported digital inflammation.

Acute irritant contact dermatitis due to Juglans regia

Juglone is the active ingredient of the green flesh of walnuts and is known to be a strong irritant. We report the first two paediatric cases of contact pigmentation and acute irritant contact dermatitis due to the juice of green walnut husks in two young nursery-school playmates.

Expression of the cyclooxygenase isoforms in the prodromal stage of black walnut-induced laminitis in horses

OBJECTIVE

To compare the levels of mRNA expression of cycooxygenase (COX)-1 and COX-2 in the digital laminae of normal horses and horses in the developmental stages of laminitis experimentally induced by administration of black walnut extract (BWE).

SAMPLE POPULATION

Samples of mRNA extracted from the digital laminae of 5 control horses and 5 horses at the onset of leukopenia after administration of BWE.

PROCEDURE

Specimens of laminae were collected from anesthetized horses prior to euthanasia. Expression of COX-1 and COX-2 mRNA in laminae of control and affected horses was evaluated via real-time quantitative polymerase chain reaction techniques.

RESULTS

Expression of COX-2 mRNA was significantly increased in the BWE-treated group, compared with that in control horses. In contrast to COX-2 regulation, COX-1 mRNA expression was not significantly different between groups. Interestingly, despite consistent clinical signs such as leukopenia in all BWE-treated horses, distinct differences in COX-2 mRNA expression were detected among those 5 horses (compared with values for control horses, the increase in COX-2 mRNA expression ranged from no increase to a 30-fold increase).

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that there was a significant upregulation of COX-2 mRNA expression during the developmental stages of laminitis, with no significant change in expression of the COX-1 isoform. These data appear to provide support for aggressive use of nonsteroidal anti-inflammatory drugs in horses at risk for laminitis; further investigation into the clinical value of selective COX-2 inhibitors for treatment of laminitis in horses appears to be warranted.

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.