An exploration of food intolerance in the primary care setting: The general practitioner's experience

A systematic review of psychological, clinical and psychosocial correlates of perceived food intolerance

OBJECTIVE

Perceived food intolerance (PFI) is a distressing condition reported by 3% - 35% of individuals, whereas prevalence of food allergy is 0.9%-3%. The present paper aims to systematically review the evidence for psychological, clinical and psychosocial factors associated with PFI in order to advance the current understanding.

METHODS

Articles published from 1970 until October 2020 were identified. Case-control, prospective cohort, cross-sectional and retrospective studies published in English that a) included a subject population of adults over 18 with PFI and b) examined psychological, clinical and/or psychosocial factors of PFI were reviewed against inclusion criteria. Methodological quality was assessed, data extracted, and a narrative synthesis conducted.

RESULTS

Of 2864 abstracts identified, thirty-six articles met inclusion criteria. Evidence consistently found PFI is associated with female sex, and individuals with PFI often report physical health complaints including gastrointestinal and extraintestinal symptoms, and gastrointestinal and atopic conditions. Evidence for an association between psychological factors and PFI was inconsistent, although some suggested increased levels of common mental disorders and distress. Findings regarding psychosocial factors were mixed and sociodemographic data were infrequently collected.

CONCLUSIONS

PFI is associated with female sex and gastrointestinal and extraintestinal complaints. Limited high-quality evidence supports the role of psychological factors associated with PFI. High-quality research using prospective and longitudinal designs with multivariate analyses is needed. Future research should explore modifiable psychological factors as potential targets for intervention and identify clinical and psychosocial risk factors of PFI to aid in formulating a biopsychosocial model of PFI.

Programmable living material containing reporter micro-organisms permits quantitative detection of oligosaccharides

The increasing molecular understanding of many diseases today permits the development of new diagnostic methods. However, few easy-to-handle and inexpensive tools exist for common diseases such as food disorders. Here we present a living material based analytical sensor (LiMBAS) containing genetically modified bacteria (Escherichia coli) immobilized and protected in a thin layer between a nanoporous and support polymer membrane for a facile quantification of disease-relevant oligosaccharides. The bacteria were engineered to fluoresce in response to the analyte to reveal its diffusion behavior when using a blue-light source and optical filter. We demonstrated that the diffusion zone diameter was related semi-logarithmically to the analyte concentration. LiMBAS could accurately quantify lactose or galactose in undiluted food samples and was able to measure food intolerance relevant concentrations in the range of 1-1000 mM requiring a sample volume of 1-10 μL. LiMBAS was storable for at least seven days without losing functionality at 4 °C. A wide range of genetic tools for E. coli are readily available thus allowing the reprogramming of the material to serve as biosensor for other molecules. In combination with smartphones, an automated diagnostic analysis becomes feasible which would also allow untrained people to use LiMBAS.

"But we're not hypochondriacs": the changing shape of gluten-free dieting and the contested illness experience

"Gluten free" exploded onto the American foodscape in recent years: as of January 2013, 30 percent of U.S. adults reported reducing or eliminating gluten in their diets. How do individuals participate in the expansion of gluten-free dieting, and what are the implications of that expansion? This article is based on 31 in-depth, semi-structured interviews conducted between May and October 2012 with gluten-free and -restricted persons. I identify three interrelated factors contributing to the expansion of gluten-free dieting among non-celiacs. Participants broaden the lay understanding of gluten-related disorders, undermine biomedical authority, and diagnose others. Such participant-driven change, termed self-ascriptive looping, is one factor in the diet's rapid popularization. I show how participants question the doctor-patient relationship and increase social contestability for other dieters. My findings challenge previous work on contested illness and suggest food intolerances may require a reconceptualization of contested illness experience.

The development and evaluation of a nurse led food intolerance clinic in primary care

OBJECTIVE

To develop a clinic for patients who believe they have a food intolerance that could be administered by practice nurses with minimal experience of dietary change or food intolerance.

METHODS

The clinic consisted of 1 week baseline, 2 weeks healthy eating plan (HE), 2 weeks wheat and dairy free plan (WD). Patients were discharged after the HE plan if their symptoms had improved, otherwise they continued onto the WD plan. Following training 4 nurses ran 4 clinics across the UK.

RESULTS

281 patients with perceived food intolerance were recruited. The most common symptoms were bowel symptoms, tiredness, stomach symptoms, and headaches. Of those who completed the programme (n=150), the majority were discharged after the HE plan as their symptoms had improved (n=106, 70.6%). A third also completed the WD plan (n=44, 29%). Symptoms, mood and quality of life improved significantly by the end of the intervention. WD showed added value as symptoms showed further improvement.

CONCLUSION

There was a need for the clinic although not on a full time basis. Symptoms improved following both the HE and WD plans.

PRACTICE IMPLICATIONS

A simple dietary based intervention may help relieve symptoms in those who believe they have a food intolerance.