Comparative Analysis of Vegetarian and Non-Vegetarian Diets on Spirometry-Measured Lung Function in Yoga Practitioners

Background: Diet and yoga both contribute significantly to overall health, particularly respiratory function. However, the impact of vegetarian and non-vegetarian diets on lung function among yoga practitioners remains unclear. This study aimed to evaluate the effect of vegetarian versus non-vegetarian diets on spirometry-measured lung function in yoga practitioners. Methods: A cross-sectional study design was employed, involving 100 yoga practitioners (50 vegetarians and 50 non-vegetarians). Participants were matched for age, gender, and duration of yoga practice. Spirometry tests measured Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), and the FEV1/FVC ratio. Data were analyzed using independent samples t-tests, paired t-tests, repeated measures ANOVA, and Pearson correlation coefficients. Ethical approval was obtained, and written informed consent was provided by all participants. Results: There were no significant differences in FVC, FEV1, or FEV1/FVC ratio between vegetarians and non-vegetarians. Both groups showed significant improvements in FVC and FEV1 post-yoga (p < 0.01). Repeated measures ANOVA indicated a significant main effect of time (p < 0.01) but no significant interaction effect between diet type and time (p = 0.34). Weak, non-significant positive correlations were found between vegetarian diet adherence and lung function parameters. Conclusions: Yoga practice significantly improves lung function, regardless of dietary pattern. Both vegetarian and non-vegetarian diets are compatible with the respiratory benefits of yoga. This suggests flexibility in dietary recommendations for yoga practitioners aiming to enhance respiratory health.


INTRODUCTION
The role of diet in optimizing health and enhancing physical performance has been a subject of considerable interest.Yoga, a holistic practice that integrates physical postures, breathing exercises, and meditation, is known to improve overall health and particularly respiratory function.Numerous studies have demonstrated that regular yoga practice can enhance lung capacity, improve respiratory muscle strength, and increase overall lung function as measured by spirometry [1][2][3].42 However, the influence of diet, specifically vegetarian versus non-vegetarian diets, on the respiratory outcomes of yoga practitioners has not been extensively studied.Diet plays a critical role in maintaining health and preventing diseases.Vegetarian diets, rich in fruits, vegetables, and whole grains, are associated with numerous health benefits, including reduced risks of chronic diseases such as cardiovascular disease and diabetes [4,5].Non-vegetarian diets, which include meat and other animal products, also offer nutritional benefits, such as higher protein intake and essential nutrients like vitamin B12 and iron [6].Despite the well-documented benefits of both dietary patterns, their specific impacts on lung function, particularly in individuals practicing yoga, remain unclear.Yoga practitioners often seek to optimize their health through lifestyle modifications, including diet [7].Understanding how different dietary patterns affect lung function in this population can provide valuable guidance for individuals aiming to maximize the respiratory benefits of yoga.Yoga has been shown to enhance lung function through various mechanisms, including increased flexibility and strength of the thoracic muscles, improved posture, and enhanced efficiency of the respiratory system [8,9].However, the potential synergistic effects of combining yoga with specific dietary patterns have not been adequately explored.This study aims to address the following research question: "How does a vegetarian diet compare to a non-vegetarian diet in terms of impact on spirometrymeasured lung function in individuals who practice yoga regularly?"By comparing the spirometry results of yoga practitioners following vegetarian and non-vegetarian diets, this study seeks to determine if one dietary pattern offers superior benefits for respiratory health.This information could have significant implications for dietary guidance in the context of yoga practice, potentially influencing dietary choices among yoga practitioners and recommendations made by health professionals.

MATERIALS AND METHODS
This study employed a comparative, cross-sectional design to evaluate the impact of vegetarian and non-vegetarian diets on spirometry-measured lung function in yoga practitioners.The study population consisted of 100 participants, all of whom regularly practiced yoga and adhered to either a vegetarian or non-vegetarian diet.Ethical approval for this study was obtained from the Institutional Ethics Committee, ensuring that all procedures were conducted in accordance with the Declaration of Helsinki.Ethical considerations were paramount throughout the study.Participants were provided with detailed information about the study's purpose, procedures, potential risks, and benefits.Written informed consent was obtained from all participants before any data collection commenced.Confidentiality and anonymity were maintained by assigning unique codes to participants and securely storing all data.Participants were allowed to withdraw from the study at any time without any repercussions.The sample size was determined using power analysis to detect a significant difference in lung function parameters between the two dietary groups, with a power of 0.80 and an alpha level of 0.05.A sample size of 100 participants (50 in each dietary group) was deemed sufficient to achieve the study objectives, accounting for potential dropouts and ensuring robust statistical analysis.Participants were recruited through yoga centers, fitness clubs, and community health events.The inclusion criteria were as follows: individuals aged 18-50 years who had been practicing yoga for at least six months, following a strict vegetarian or non-vegetarian diet for the same duration, and willing to provide informed consent.Exclusion criteria included current smokers, individuals with chronic respiratory conditions (e.g., asthma, COPD), those on medications affecting lung function, and participants with recent respiratory infections.Data collection involved a two-step process.Initially, a detailed questionnaire was administered to gather demographic information, dietary habits, yoga practice details, and health history.Following this, spirometry tests were conducted using a calibrated spirometer.The primary spirometry parameters measured included Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), and the FEV1/FVC ratio.All spirometry tests were performed by trained technicians in a controlled environment, adhering to the American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines to ensure accuracy and reliability.The data analysis was performed using SPSS (Statistical Package for the Social Sciences) version 25.0.Descriptive statistics were used to summarize the demographic and baseline characteristics of the participants.Independent samples t-tests were conducted to compare the mean spirometry values between the vegetarian and non-vegetarian groups, assuming normal distribution of data.Paired t-test was used to analyze within-group differences in pre-and post-yoga session spirometry results.Repeated measures ANOVA was utilized to assess the changes in lung function over time, considering the interaction between diet type and spirometry outcomes.Pearson or Spearman correlation coefficients were calculated to explore relationships between dietary patterns and lung function parameters.

RESULTS
The study evaluated the impact of vegetarian and non-vegetarian diets on spirometry-measured lung function in 100 yoga practitioners.The participants were divided into two groups based on their dietary habits: 50 vegetarians and 50 non-vegetarians.The demographic and baseline characteristics of the participants are summarized in Table 1.The mean age of the participants was 35.4 ± 7.8 years, with no significant age difference between the vegetarian (34.9 ± 8.1 years) and non-vegetarian groups (35.8 ± 7.6 years) (p = 0.62).The gender distribution was 60% female and 40% male, evenly distributed across both groups (p = 0.98).The average duration of yoga practice was 3.5 ± 1.2 years for vegetarians and 3.7 ± 1.3 years for non-vegetarians (p = 0.45), indicating comparable levels of yoga experience.values between the vegetarian and non-vegetarian groups.The results indicated no significant differences in FVC (p = 0.19), FEV1 (p = 0.29), or the FEV1/FVC ratio (p = 0.46) between the two dietary groups.These findings suggest that the type of diet did not significantly affect the overall lung function as measured by these parameters.Paired t-tests were used to analyze within-group differences in spirometry parameters from pre-yoga to post-yoga sessions.Both groups showed significant improvements in FVC and FEV1 post-yoga (p < 0.01 for both groups), indicating the beneficial effects of yoga practice on lung function.Repeated measures ANOVA was utilized to assess the changes in lung function over time, considering the interaction between diet type and spirometry outcomes.The analysis revealed a significant main effect of time (p < 0.01), indicating overall improvements in lung function post-yoga.However, there was no significant interaction effect between diet type and time (p = 0.34), suggesting that the improvements in lung function were similar across both dietary groups.
Pearson correlation coefficients were calculated to explore relationships between dietary patterns and lung function parameters.The analysis showed a weak but positive correlation between vegetarian diet adherence and FVC (r = 0.15, p = 0.13) and FEV1 (r = 0.12, p = 0.24), although these correlations were not statistically significant.
Participants' self-reported adherence to their respective diets and yoga practices was high, with 95% of vegetarians and 92% of non-vegetarians reporting consistent adherence to their dietary patterns and yoga routines.There were no significant differences in the frequency of yoga practice between the two groups (p = 0.67).

DISCUSSION
The study's demographic and baseline characteristics showed no significant differences between the vegetarian and non-vegetarian groups in terms of age, gender distribution, and duration of yoga practice.This homogeneity is crucial for minimizing confounding variables that could influence the outcomes of lung function tests.Both groups had a balanced representation of males and females and similar levels of yoga experience, ensuring that the observed effects on lung function could be attributed primarily to dietary differences and not to other demographic factors.The primary spirometry parameters, FVC and FEV1, were not significantly different between the vegetarian and non-vegetarian groups.These findings align with some previous studies that have shown no substantial difference in lung function between vegetarians and non-vegetarian [2,4].However, other studies have suggested that vegetarian diets, rich in antioxidants and anti-inflammatory components, might enhance lung function [10].The absence of significant differences in this study could be due to the relatively small sample size or the similar overall health and fitness levels of the participants, given their regular yoga practice.
The FEV1/FVC ratio, an indicator of airflow obstruction, was also similar between the groups.This suggests that neither diet had a detrimental effect on airway function.Similar results have been observed in studies comparing vegetarians and non-vegetarians in different populations [11].The significant improvements in FVC and FEV1 post-yoga sessions within both dietary groups confirm the beneficial effects of yoga on lung function.Yoga is known to enhance respiratory muscle strength, increase lung capacity, and improve overall respiratory efficiency [12].These findings are consistent with previous research demonstrating that regular yoga practice can lead to significant improvements in spirometry parameters [13].
The repeated measures ANOVA revealed a significant main effect of time, indicating overall improvements in lung function post-yoga, but no significant interaction effect between diet type and time.This suggests that the respiratory benefits of yoga are independent of dietary patterns.Similar studies have found that yoga practice improves lung function regardless of other lifestyle factors [3].
The lack of a significant interaction effect might indicate that the type of diet does not enhance or diminish the lung function benefits derived from yoga practice.
The weak but positive correlations between vegetarian diet adherence and FVC/FEV1, although not statistically significant, suggest a potential trend that warrants further investigation.Some studies have indicated that vegetarian diets, being high in fruits and vegetables, may contribute to better lung function due to higher intakes of vitamins, minerals, and antioxidants [8].Several limitations should be noted.The sample size of 100 participants, while adequate for preliminary analysis, may not be large enough to detect subtle differences between dietary groups.The study also relied on self-reported dietary adherence and yoga practice, which could introduce bias.Additionally, the crosssectional design limits the ability to establish causality between diet, yoga practice, and lung function.Despite these limitations, the study has several strengths.It employs rigorous spirometry testing following ATS/ERS guidelines, ensuring the reliability of lung function measurements.The study also controls for potential confounding variables by matching the groups in terms of age, gender, and yoga experience.The use of both subjective and objective measures to assess adherence enhances the study's validity.
The findings of this study have significant clinical implications.They suggest that both vegetarian and non-vegetarian diets can be compatible with the respiratory health benefits conferred by regular yoga practice.This information can guide healthcare providers in offering flexible dietary recommendations to yoga practitioners, emphasizing the importance of consistent yoga practice for improving lung function.Moreover, the study reinforces the role of yoga as a non-pharmacological intervention to enhance respiratory health, which could be particularly beneficial in managing conditions like asthma and COPD.

Table 2 . Spirometry Parameters (Mean ± SD)
Independent samples t-tests were conducted to compare the mean spirometry 44

Table 3 . Within-Group Spirometry Changes (Mean ± SD)
Butler et al. (2001)000)ant correlations in this study highlight the complexity of diet-lung function relationships and suggest that other factors, such as overall lifestyle and genetic predispositions, may play more substantial roles.Studies byBirkel and Edgren (2000)andSharma et al. (2013)have shown similar improvements in lung function with yoga practice, supporting the findings of this study.Additionally, studies comparing vegetarians and non-vegetarians in terms of respiratory health have also found no significant differences in spirometry parameters, aligning with this study's results.Conversely, studies byCross et al. (1999)andButler et al. (2001)reported better lung function among vegetarians compared to non-vegetarians, attributing this to the higher antioxidant intake in vegetarian diets.These dissimilar findings could be due to differences in study populations, dietary adherence, and other lifestyle factors that were controlled for in different ways.