European Journal of Cardiovascular Medicine

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide, accounting for an estimated 17.9 million deaths each year (1). Among the numerous modifiable risk factors for CVD, dyslipidemia plays a significant role. Elevated levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TG), along with reduced high-density lipoprotein cholesterol (HDL-C), have been consistently linked with an increased risk of atherosclerosis and coronary artery disease (2,3). Dietary habits are a crucial determinant of lipid metabolism and hence directly influence lipid profiles.

Vegetarian diets are typically characterized by higher intakes of dietary fiber, antioxidants, and unsaturated fats, and lower consumption of saturated fats and cholesterol. These dietary patterns are associated with lower levels of serum lipids and a reduced risk of cardiovascular morbidity and mortality (4). In contrast, non-vegetarian diets, particularly those rich in red and processed meats, have been linked to adverse lipid profiles and greater cardiovascular risk (5).

Several studies have reported that individuals adhering to vegetarian diets tend to have lower body mass indices, blood pressure, and improved lipid parameters compared to their non-vegetarian counterparts (6,7).

Despite the growing interest in plant-based diets, the comparative impact of vegetarian versus non-vegetarian dietary patterns on lipid profiles in different populations remains a subject of ongoing investigation. Given the increasing prevalence of lifestyle-related disorders in both developed and developing nations, understanding the role of dietary choices in lipid regulation is of significant public health importance.

This study aims to compare the serum lipid profiles—total cholesterol, LDL-C, HDL-C, and triglycerides—between vegetarian and non-vegetarian adults, to assess whether plant-based dietary habits confer measurable benefits in lipid management and potential cardiovascular protection.

The study included a total of 100 adult participants aged 25 to 55 years, divided equally into two groups: vegetarians (n = 50) and non-vegetarians (n = 50). Vegetarian participants were defined as individuals who had consistently followed a plant-based diet, excluding all forms of meat, poultry, and fish for at least the previous five years. Non-vegetarians were those who regularly consumed meat or fish at least three times a week over the same period. Subjects with a history of chronic illness, lipid-lowering drug usage, endocrine disorders, or recent hospitalization were excluded.

Data Collection:
A structured questionnaire was used to gather demographic details, dietary patterns, lifestyle factors, and medical history. Participants underwent anthropometric measurements including height, weight, and body mass index (BMI) calculation.

Blood Sample Collection and Analysis:
Fasting venous blood samples were collected from all participants after a minimum of 10–12 hours of overnight fasting. The samples were centrifuged to separate serum, which was then analyzed for the following lipid parameters: Total Cholesterol (TC), Triglycerides (TG), Low-Density Lipoprotein Cholesterol (LDL-C), and High-Density Lipoprotein Cholesterol (HDL-C). All lipid estimations were carried out using enzymatic colorimetric methods with an automated biochemistry analyzer (e.g., Roche/Hitachi Cobas c system).

Statistical Analysis:
The collected data were entered into Microsoft Excel and analyzed using SPSS version 25.0 (IBM Corp., Armonk, NY, USA). Mean and standard deviation (SD) were calculated for all continuous variables. An independent sample t-test was used to assess the differences in lipid parameters between the two groups. A p-value of less than 0.05 was considered statistically significant.

The study included 100 participants, evenly divided into vegetarians (n = 50) and non-vegetarians (n = 50). The mean age of the vegetarian group was 37.8 ± 8.6 years, while that of the non-vegetarian group was 38.4 ± 9.1 years. The mean BMI was comparable between the two groups (23.5 ± 2.4 kg/m² in vegetarians vs. 24.2 ± 2.7 kg/m² in non-vegetarians; p = 0.18).

Table 1 presents the comparison of lipid parameters between vegetarians and non-vegetarians. The mean total cholesterol level was significantly lower in vegetarians (162.4 ± 24.1 mg/dL) compared to non-vegetarians (193.6 ± 30.2 mg/dL; p < 0.001). LDL-C levels also showed a notable reduction in the vegetarian group (98.5 ± 18.7 mg/dL) compared to the non-vegetarian group (121.7 ± 21.5 mg/dL; p = 0.002).

HDL-C was higher in vegetarians (52.3 ± 6.4 mg/dL) as opposed to non-vegetarians (46.1 ± 7.1 mg/dL; p = 0.015), indicating a more favorable lipid profile. Triglyceride levels were also significantly lower among vegetarians (102.6 ± 19.3 mg/dL) than in non-vegetarians (138.9 ± 26.7 mg/dL; p = 0.001).

These differences are summarized in Table 1, which illustrates the statistically significant improvements in lipid parameters among vegetarian individuals compared to their non-vegetarian counterparts.

Table 1: Comparison of Serum Lipid Profile Between Vegetarians and Non-Vegetarians

The findings of the present study demonstrate a significant difference in serum lipid profiles between vegetarian and non-vegetarian individuals. Vegetarian participants exhibited lower total cholesterol, LDL-C, and triglyceride levels, along with higher HDL-C values, which are indicative of a more favorable cardiovascular risk profile.

Diet plays a pivotal role in modulating lipid metabolism. Vegetarian diets, typically rich in whole grains, legumes, fruits, vegetables, and dietary fiber, have been associated with improved lipid profiles and reduced cardiovascular risk (1,2). The lower intake of saturated fats and dietary cholesterol in plant-based diets is considered a primary factor contributing to reduced levels of total and LDL cholesterol (3,4). In contrast, non-vegetarian diets often contain higher amounts of saturated fats and trans fats, which have been linked to elevated LDL-C and total cholesterol levels (5).

Several epidemiological studies support our observations. Vegetarian diets significantly reduce serum total cholesterol and LDL-C compared to omnivorous diets (6,7). The present study aligns with these findings and contributes additional evidence from an urban Indian population.

The elevated HDL-C levels observed among vegetarians in this study are consistent with findings from other research indicating that diets high in polyunsaturated fats, fiber, and plant sterols can enhance HDL levels (8,9). HDL-C is known for its protective role in reverse cholesterol transport and has been inversely associated with cardiovascular events (10).

Triglyceride levels were also significantly lower in vegetarians. This could be attributed to a lower glycemic load and healthier fat composition of vegetarian diets, which promote better insulin sensitivity and lipid regulation (11,12). In contrast, diets rich in refined carbohydrates and saturated fats, common in non-vegetarian diets, may contribute to hypertriglyceridemia (13).

Body weight and BMI, although not significantly different between the groups in our study, have been identified in previous literature as mediators of lipid metabolism. Vegetarian diets have been linked with healthier BMI and reduced adiposity, both of which are associated with better lipid outcomes (14). However, lifestyle factors such as physical activity, alcohol use, and smoking were not extensively evaluated in this study, which may act as potential confounders.

Furthermore, nutrient diversity within vegetarian diets—such as the inclusion of omega-3 fatty acids from flaxseeds and walnuts or the use of fortified foods—also plays a critical role in maintaining lipid balance (15). Education on balanced vegetarian nutrition is essential to ensure not just cardiovascular benefits but overall nutritional adequacy.

Despite its strengths, the present study has limitations, including its relatively small sample size and cross-sectional design, which limits the ability to establish causal relationships. Additionally, self-reported dietary practices might be subject to recall bias. Future studies involving larger cohorts and longitudinal follow-up are warranted to validate these findings and explore the mechanistic pathways linking diet and lipid regulation.

This study demonstrates that individuals following a vegetarian diet have significantly better lipid profiles compared to non-vegetarians, with lower total cholesterol, LDL-C, and triglycerides, and higher HDL-C levels. These findings suggest that adopting a plant-based diet may contribute to improved cardiovascular health and reduced risk of dyslipidemia-related disorders. Promoting vegetarian dietary habits could be a beneficial public health strategy for cardiovascular disease prevention.

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