Research Updates - Salicylates

The abstracts below are from articles released after the publication of Beyond the Salicylate Handbook

Possible links between food related salicylates and IBS in some individuals

Abstract
Background and Aim: An elimination-rechallenge dietary approach targeting naturally-occurring bioactive chemicals has been proposed to alleviate functional gastrointestinal symptoms. A major focus of this approach is salicylates. This study aimed to address the potential role of dietary salicylates in the induction of symptoms in patients with irritable bowel syndrome (IBS).

Methods: A pilot, double-blind, randomized, cross-over trial of 2-week low- versus high-salicylate diets (6.6 and 27.9 g/day salicylate, respectively) was undertaken. All foods were provided containing minimal quantities of other potential food triggers. Gastrointestinal and extraintestinal symptoms were measured daily using a 100-mm visual-analogue-scale.

Results: Ten participants with IBS completed the study, including one with known aspirin-sensitivity. Overall, no differences in symptoms were observed (P = 0.625; Friedman test). However, clear symptom provocation was seen in the aspirin-sensitive participant, with all abdominal symptoms and tiredness worsening during the high-salicylate diet. A similar trend was seen in another participant, where abdominal symptoms gradually worsened during the high-salicylate diet.

Conclusions: These results provide some evidence that food-related salicylates may influence the genesis of symptoms in a subset of patients with IBS. A larger cohort is needed to determine the incidence of salicylate-sensitivity and further evaluate the diet as a potential therapeutic target.

Naturally-occurring dietary salicylates in the genesis of functional gastrointestinal symptoms in patients with irritable bowel syndrome: Pilot study. Caroline J Tuck, Sreepurna Malakar, Jacqueline S Barrett, Jane G Muir, Peter R Gibson.  https://doi.org/10.1002/jgh3.12578

Effectiveness of Personalized Low Salicylate Diet in the Management of Salicylate Sensitivity

Abstract: Salicylic acid and its derivatives (including acetylsalicylic acid/aspirin) are popular in medicine. They also occur naturally in many food products. The aim of the study was to investigate the effect of the personalized low salicylate diet (PLSD) on the reduction of asthma, rhinosinusitis and urticaria symptoms in patients with hypersensitivity to aspirin (ASA) or nonsteroidal anti-inflammatory drugs (NSAIDs). To achieve the research goal, a prospective, nonrandomized, baseline-controlled intervention study was conducted. Thirty patients diagnosed with NSAIDs hypersensitivity, who despite pharmacotherapy had symptoms of hypersensitivity, were included in the study. The PLSD was recommended for all participants for a period of two to four weeks. The intensity of subjectively declared symptoms of asthma, rhinosinusitis and urticaria were measured before and after dietary intervention, using, respectively, the asthma control test (ACT), the sino-nasal outcome test (SNOT-22) and the four-item itch questionnaire (FIIQ). Diet adherence and salicylate intake were measured by a 3-day food record. The severity of symptoms improved significantly after the intervention. The median of the ACT score was 24 scores before and 25 after the dietary intervention (p < 0.002), the median of the SNOT-22 score was 25 before and 13 after a dietary intervention (p < 0.0002) and the median of the FIIQ score was 5 before and 0 after a dietary intervention (p < 0.0002). The intake of salicylates decreased from 0.79 mg/day (before intervention) to 0.15 mg/day (p < 0.001) (during intervention). Although the usefulness of a low salicylate diet in the treatment of salicylate hypersensitivity is controversial, the results of our study indicate that the PLSD may have a positive effect in reducing symptoms of salicylate hypersensitivity and could be an additional tool supporting the therapy of these patients.

Effectiveness of Personalized Low Salicylate Diet in the Management of Salicylates Hypersensitive Patients: Interventional Study. Paulina K. Kęszycka , Ewa Lange, Danuta Gajewska. Nutrients 2021, 13(3), 991; https://doi.org/10.3390/nu13030991

Salicylic acid contained in fruits and vegetables may act as an important cofactor in LTP (lipid transfer protein) syndrome

Abstract: We report a 16-year-old Japanese male with mugwort pollinosis in whom ingestion of wild grape juice and various vegetables caused recurrent general urticaria, abdominal pain, dyspnea, and loss of consciousness. A skin prick test demonstrated positive reactions to a wide variety of both non-heated and heated vegetables and fruits such as wild grape, bell pepper, onion, Chinese cabbage, tomato, eggplant, and broccoli. The serum immunoglobulin E levels (ImmunoCAP ISAC®) for Art v 3, Pla a 3, Pru p 3, and Jug r 3, which are lipid transfer protein (LTP) homologs, were positive but those for Bet v 1 and Bet v 2 were negative. We diagnosed the patient as having LTP syndrome, a condition in which additional factors such as exercise, non-steroidal anti-inflammatory drugs, or alcohol may trigger an allergic reaction. Wild grapes contain a large amount of salicylic acid, and in our patient ingestion of wild grape juice led to immediate loss of consciousness in the absence of exercise. This suggests that salicylic acid contained in fruits and vegetables may act as an important cofactor in LTP syndrome. Although sensitization to LTP is rarely reported in Asia, LTP are considered to be potentially life-threatening food allergens, and therefore warrant attention.

Lipid transfer protein syndrome due to wild grape juice and various vegetables: A life-threatening food allergen. Miho Hanada, Michiyo Nakagawa, Akemi Hamabata, Hiroo Amano. https://doi.org/10.1111/1346-8138.16010

Effect of low salicylate diet on clinical and inflammatory markers in patients with aspirin exacerbated respiratory disease

Abstract
Background: Aspirin-exacerbated respiratory disease (AERD) is characterized by eosinophilic rhinosinusitis, nasal polyposis, and bronchial asthma, along with the onset of respiratory reactions after the ingestion of nonsteroidal anti-inflammatory drugs (NSAIDs) or acetylsalicylic acid (ASA). In addition to the therapeutic routines and surgical options available, a low dietary intake of food salicylate has been suggested as adjunctive therapy for this condition. This study aimed to assess the influence of a short-term low salicylate diet on inflammatory markers in patients with AERD and whether that would result in symptomatic improvement.

Methods: Prospective study with randomization to either a high or low salicylate diet for 1 week, followed by cross-over to the other study arm. Participants were asked to record their dietary salicylate for each week of the study. Urinary creatinine, salicylate and leukotriene levels were measured at the time of recruitment, end of week one and end of week two and the SNOT-22 questionnaire was filled out at the same time points.

Results: A total of seven participants completed the study. There was no statistical difference in the urinary salicylate and leukotriene levels between the two diets; nevertheless, participants on low salicylate diet reported improved SNOT-22 symptoms scores (p = 0.04), mainly in the rhinologic, ear/facial, and sleep dysfunction symptom domains. In addition, these last two domains outcomes were more significant than the minimal clinically important difference.

Conclusions: A short-term low salicylate diet may not result in biochemical outcomes changes but seems to provide significant symptomatic relief for patients with AERD.

Sowerby, L.J., Patel, K.B., Schmerk, C. et al. Effect of low salicylate diet on clinical and inflammatory markers in patients with aspirin exacerbated respiratory disease – a randomized crossover trial. https://doi.org/10.1186/s40463-021-00502-4