ORIGINAL RESEARCH ARTICLE

Background:

symptoms or influencing disease progression. 5,6In the last 10 years, research has discovered various biochemical and cellular markers that represent diverse pathways contributing to asthma's complexity. 7The relationship between asthma and FAs is multifaceted, involving immunological, dietary, and genetic factors that interplay to influence an individual's clinical presentation and response to treatment. 5Ensuring a balanced diet covering the proper levels of micro-, macro-nutrients, and vitamins can potentially enhance asthma management and alleviate its symptoms. 8ndia's rich culinary traditions, characterised by a multitude of ingredients and preparations, present a unique context to investigate how dietary factors may impact asthma outcomes.Furthermore, the nutritional status and dietary habits of asthma patients in India are influenced by socioeconomic factors, cultural practices, and regional variations, all of which can profoundly affect their overall health and well-being. 9his study aims to delve into a comprehensive analysis of biochemical markers and nutrient profiles and strives to contribute to the growing body of knowledge surrounding asthma management, potentially offering new avenues for personalized therapeutic strategies tailored to the unique dietary and nutritional needs of Indian asthma patients.

Study participants
This study was carried out among clinically and spirometrically diagnosed asthma patients attending the outpatient clinic at Department of Pulmonary Medicine, Gandhi Medical College, Hyderabad, and controls aged between 15 and 40 years from 2010 to 2012.A total of 286 participants (143 cases -asthma patients with perceived FA and 143 controls -comparable age, sex, SES asthma patients without perceived FA) were enrolled in the study.The SES was assessed and compared based on the Kuppuswamy Scale. 10 Perceived FA was characterized by patients reporting that specific food item(s) triggered or exacerbated their asthma symptoms.
The study was approved by the Ethics Committee of coordinating center (05/II/2016) and study site (IEC/ GMC/2017).After explaining the Patient Information Sheet to the participants, who met all the inclusion and exclusion criteria and signed Informed Consent Document to participate in the study were included in the final analyses.

Pulmonary function test
Pulmonary function test (PFT) was performed in asthma patients as well as healthy controls.Curves for FEV1 and flow volume were obtained with a spirometer (P.K. Morgan's Spiro 232 Pulmonary System).FEV1 data were presented as percentages (100%) after adjusting for age and sex.Data confirming obstruction include increased residual volume and airway resistance, uneven distribution of ventilation, and decreased forced expiratory volume for 1 s (FEV1) according to the requirements of the American Thoracic Society. 11Reversibility of airway obstruction in response to administration of an aerosol bronchodilator (400 mg of salbutamol) was measured according to the standard method of the American Thoracic Society. 11,12A positive reversibility test was defined by an increase in FEV1 higher than 12% after inhalation of 400 mg of salbutamol.

Anthropometric measurements
Height: Participants' height was measured in centimeters using a stadiometer.They were instructed to stand upright against the stadiometer's vertical backboard.The stadiometer was then lowered gently until it touched the top of the participant's head, accounting for any hair, and the measurement was taken at that point.
Weight: Weight was measured using a digital scale in kilograms.Participants stood barefoot with even weight distribution on the scale.Prior to each measurement, the scale was calibrated to ensure accuracy by reading zero with no weight applied.
Body mass index (BMI): The BMI was calculated using the formula; weight (kg)/(height (m)). 2 Based on the calculated BMI, participants were categorized into different groups, such as underweight, normal weight, overweight, and obese, following established BMI thresholds. 13

POPULAR SCIENTIFIC SUMMARY
 People with asthma who believe they have food allergies tend to have higher rates of being overweight and anemia. They also often have higher levels of a substance called IgE in their blood and lower levels of protein and calcium. These findings show how asthma, food allergies, and what we eat are all connected, especially considering the variety of diets across different regions of India.

Food frequency questionnaire
The food frequency questionnaire (FFQ) was developed and evaluated by drawing inspiration from an existing, previously published questionnaire focused on dietary habits. 15A total of150 item semiquantitative FFQ was used to assess normal dietary intake during the previous 6 months.Nutrient intake was computed from the reported frequency of consumption of each specified unit of food or beverage and from published data on the nutrient content of the specified portions. 16To help the participants to quantify food consumption, photographs showing servings with six progressive portions of the reported consumed foods were shown to the participants.
Participants were asked about their current smoking habits, including whether they were current smokers, former smokers, or non-smokers.

Statistical analysis
Statistical analyses were performed by using the SPSS statistical package version 22.0 (SPSS, Chicago, IL).The characteristics of cases and controls are expressed as mean/frequency and standard deviation/percentages and 95% confidence intervals for variables.Categorical data of cases and control groups was evaluated using the chi-square test and continuous normal values tested by t-test.Results were considered statistically significant if the observed twosided significance level (p-value) was not greater than 0.05.
Asthmatics with perceived FA were anemic with hemoglobin level measured to be 9.7 ± 1.2 (9.5-9.9)mg/ dl, which was significantly low (p < 0.001) compared to control group [ Comparison of dietary intake between the cases (asthma patients with perceived FAs) and controls (asthma patients without perceived FAs) revealed significant differences in various nutrient consumption levels.The mean daily intake of protein was markedly lower in cases  3).

DISCUSSION
Diverse dietary practices in India significantly impact asthma within varying cultural and regional contexts, influencing the nutritional status and overall health of patients.To the best of our knowledge, this study stands as the pioneering investigation, delving into the biochemical profile and nutrient status of adult asthma patients with perceived FAs in the Hyderabad population of South India.The demographic details showed that most of the population who participated in the study was from urban background, reflecting the urban-centric nature of the study cohort.In addition, a significant proportion of participants reported never having smoked, suggesting that smoking may not be a predominant factor in the asthma population under consideration.An epidemiological study 17 found that while smoking is less prevalent among individuals with asthma compared to the general population, one in four asthma patients continues smoking.These individuals experience notably more chronic cough and phlegm than both never smokers and ex-smokers.Thus, emphasizing the crucial need for smoking cessation in all asthma patients, including those with milder forms of the condition.
Asthma patients reporting FAs showed a higher incidence of pre-obesity/overweight (BMI 25-30) compared to those without FAs, while a larger proportion of asthma patients without perceived FAs fell within the normal BMI range (18.5-25).These findings emphasize the potential connection between BMI and asthma, highlighting a notable pre-obesity prevalence among asthmatics with perceived FA.Previous research 18 has often linked obesity to increased FAs, attributing immune system changes and gut barrier disruptions as possible causes.Furthermore, while numerous studies 19,20 have indicated a connection between obesity and asthma, particularly in adults.Chronic low-grade inflammation observed in overweight to obese individuals, 21 alongside linking obesity with higher IgE levels in women 22 and mechanisms involving adipose tissue's influence on the immune system, suggest a potential connection between obesity and allergies. 23Variations in asthma prevalence Priyanka Dadha and Himaja Nallagatla Biochemical & Nutrient profile of asthmatics with FA by gender, as seen in Korean adults, hint at malnutrition and obesity contributing to asthma mechanisms. 24urthermore, the role of metabolic dysfunction rather than fat mass alone in asthma related to obesity has been highlighted, 25 yet such investigations in the Indian context remain sparse, making this study pivotal in proposing a healthy BMI as a possible factor in mitigating allergy and asthma effects.Asthma patients with perceived FA showed anemia with lower hemoglobin levels, elevated TLC, specifically higher eosinophil and monocyte counts, increased serum IgE levels indicating pronounced atopic responses, and lower serum protein and calcium levels, hinting at potential malabsorption or nutritional issues.Allergic adults, particularly males, face a 3.5-fold higher risk of developing iron deficiency anemia, while allergic females experience an increased risk of about 66%. 26A study 27 examined the correlation between childhood anemia and atopic diseases, revealing a consistent association.Recent research 28,29 has connected iron deficiency with inflammatory disorders such as rheumatoid arthritis, chronic obstructive pulmonary disease, and irritable bowel disease.Iron levels affect the proliferation of Th subset cells, with deficiency favoring Th2 cell proliferation, altering the Th1/Th2 ratio, and potentially promoting allergic sensitization. 30It further highlighted associations between maternal iron deficiency anemia and respiratory illnesses/allergies in children. 31The study's results on adults found consistent links between asthma, FA and anemia in adults, highlighting the need for further exploration of the factors driving this association.
A decrease in TLC after consuming allergenic foods aligns with increased eosinophil levels, improving diagnostic accuracy. 32Vaughan's 1934 leukopenic index observed significant changes in leukocyte counts postingestion to detect allergic reactions. 33Asthma patients in a study of 53 individuals showed higher eosinophil (OR = 12.61, p < 0.0001) and basophil (OR = 6.00, p < 0.0001) counts and reduced monocytes (OR = 13.79,p = 0.017), indicating heightened chronic inflammation. 34osinophils may contribute to asthma exacerbation through various mechanisms involving Th2 cytokines and virus infection-related proteins. 35gE-mediated FAs rapidly trigger histamine release, causing immediate symptoms, distinct from delayedonset non-IgE-mediated allergies.36 Serum IgE levels, notably elevated in South Indian asthmatics 37 (151.95IU/mL in healthy individuals to 1045.32 IU/mL in severe cases), hold diagnostic value for predicting atopy and type 2 asthma, essential for allergy management and diagnosis but normal ranges vary among ethnic groups.38 Changes in serum calcium levels are associated with acute respiratory failure, emphasizing the potential misrepresentation when solely assessing serum calcium. 39The gold standard for accurate calcium status evaluation involves measuring ionized calcium levels.40 A study 41 found the availability of highly sensitive C-reactive protein (hs-CRP) assays for detecting subtle changes in CRP levels within the reference range, facilitating the assessment of clinical inflammation.There was absence of estimation for serum proteins such as cytokines and other inflammatory markers and ionized calcium levels. Cosequently, the lower serum protein and calcium levels observed among asthma patients, compared to the control group, were solely linked to reduced protein and calcium intake without considering other potential factors.
Despite similar calorie intake, asthma patients showed significant variations in micronutrient consumption, including vitamins and minerals.Asthma patients tended to consume lower protein and higher fat compared to the control group, which preferred a protein-rich, lower-fat diet.Western world does not support an association between a Western diet and incident or prevalent adult asthma but does suggest a possible link between a Western diet pattern and adult asthma morbidity. 42Observational studies 43,44,45 examine vitamins (A, C, D, E) and methyl donor nutrients (folate, B12, choline) concerning asthma.Thiamine hydrochloride can trigger allergic reactions, while riboflavin (vitamin B2) has demonstrated potential antihistamine effects.Since histamines are known to have a very important role to play in allergies and asthma supplementation with riboflavin might help in relieving the patients from intensity of asthma attacks.A study 46 found higher riboflavin intake alleviates lung issues related to dibutyl phthalate exposure; vitamin B6 supplementation reduced allergy and asthma symptoms. 47Vitamin C showed promise in reducing post-exercise FEV1 decline by 48% 48 and asthma attacks by 89%, 49 hinting at its potential in slowing lung function decline 50 and aiding in chronic obstructive pulmonary disease prevention. 51Folic acid is vital for preventing neural tube defects but its intake in pregnant women may increase the risk of allergic diseases in infants, particularly respiratory tract allergies. 52onflicting studies persist regarding its role in preventing allergies in babies, with some advocating higher doses while others showing no direct link between maternal intake and childhood allergies or asthma. 53itamin B12's impact on folate metabolism is significant, 54 but its relationship with childhood asthma, atopy, wheezing, or eczema lacks consistent findings across studies, 55,56 requiring more research for clarification.
Lower calcium levels in allergy patients due to limited dairy intake from negative beliefs about dairy contrast previous research 57 suggests calcium's limited role in alleviating allergies.Recent research 58 underscores vitamin D's correlation with allergy prevention, though the present study didn't assess vitamin D levels.Studies link prenatal vitamin D supplementation (in Ireland) 59 and adequate maternal vitamin D (in India) 60 to reduced offspring asthma/allergy risks.However, limited data exist on diverse biochemical profiles and diets in adult asthma patients with or without perceived FAs.
The study on asthma, perceived FAs, and their connection to biochemical markers and nutrient profiles not only holds key strengths but also notable limitations.Nonetheless, its limitations, including a narrow geographical focus, a small sample size, a cross-sectional design, and reliance on selfreported data, could restrict generalizability and causal inferences.Limited consideration of confounding variables and absence of comprehensive biochemical parameters and longitudinal follow-up pose significant constraints.

CONCLUSION
The study provides valuable insights into the potential links among asthma, perceived FAs, and the biochemicalnutritional profiles of individuals in Hyderabad, India.It underscores the importance of dietary considerations in managing asthma within the Indian context, suggesting avenues for tailored therapeutic approaches.These efforts would offer a more nuanced comprehension of managing asthma and FAs.Emphasizing the intricate relationship between dietary factors, asthma, and atopy, future research should conduct population-based studies on micronutrient deficiency and explore the role of BMI in FAs.Furthermore, imperative intervention trials are warranted to authenticate the influence of dietary components such as antioxidants, fiber, and vitamins in controlling and preventing asthma.