IJCS | Volume 32, Nº6, November / December 2019

632 Pimentel et al. Nutritional status and vegetarians Int J Cardiovasc Sci. 2019;32(6):623-634 Original Article Mean dietary fiber intake was 22 g per day, lower than the recommended value of 25 g/day according to the Brazilian Ministry of Health. The low fiber intake may be explained by a diet based on refined cereals and low intake of fruits, vegetables and whole cereals. In this context, potential benefits of a well-balanced vegetarian diet would be of value, due to its main characteristic of low or no consumption of animal meat combined with increased intake of vegetable foods. 37 Population-based studies have showed that, compared with an omnivore diet, vegetarian diets have higher nutrient density. 38 The concept of nutrient density is defined by Phillip et al. 2 as the amount of nutrient (g or mg) divided by the total of calories. Vegetarians consume fewer calories and higher amounts of fibers, vitamins A, C and E, thiamin, riboflavin, folate, calcium, magnesium, iron and potassium. 28,38 The correct intake of all food groups may also normalize plasma lipid and lipoprotein levels, and for this reason, vegetarians are more likely to have normal lipid levels. A recent study by Najjar et al. 39 showed that a plant-based diet has a favorable effect on lipid levels and reduces inflammatory markers and other atherogenic lipoproteins and particles. The authors showed that the levels of HDL-c were significantly higher in vegetarians than in omnivores; it is known that increased HDL-c levels are associated with reduced relative risk for CVDs. 39 A meta-analysis involving 4,177 individuals was conducted to compare the effects of vegetarian and omnivore diets on HDL-c. 40 Different from what was expected from the authors, vegetarian diets did not alter plasma HDL-c [standardized mean difference (SMD) = 0.02 mmol/l; 95% confidence interval (CI): 20.19 to 0.22 mmol/l]. In Asia and Latin America countries, no significant differences in HDL-c levels were found between vegetarians and omnivores (SMD = 20.09 mmol/l; 95% CI: 20.43 to 0.25 mmol/l), and in Europe and North America countries, plasma HDL-c was also not different between the two diets (SMD = 0.09 mmol/l; 95% CI: 20.19 to 0.36 mmol/l). So far, available studies in Brazil are not sufficient to support these conclusions. In our study, the higher levels HDL-c in vegetarians compared with omnivores may have been associated with the practice of exercise, which was more frequent in this group, in addition to the absence of smoking habits and higher consumption of monounsaturated fatty acids in this group (not forgetting the genetic predisposition). However, this study was focused on assessing the nutritional status rather than food intake of participants. Other studies involving vegetarian individuals have reported contradicting results. A study with Buddhist vegetarians showed significantly higher BMI and body fat in these individuals compared with omnivores. 38 The authors attributed this finding to their habits of consuming fried foods, common to the Asian cooking style. In scientific literature, contradictory findings are as important as conclusive ones, as they may encourage newway of thinking and hypothesis formulation, leading to advances in scientific knowledge. Therefore, it is erroneous to think that the adoption of a vegetarian diet will necessarily promote improvements in biochemical parameters. Factors like ethnicity, culture, among others, may exert an important influence on following a so-called ‘healthy’ diet. This study has some limitations that deserve to be mentioned. Since this was a cross-sectional study, both exposure and outcomes were collected at the same time point. For this reason, neither temporal or a causal relationship between the events could be established, nor could we determine whether the results were influenced by facts of the past. Also, regarding the use of nutritional supplements, since we did not evaluate their nutritional composition, the possibility that they constituted a confounding factor cannot be ruled out. Another possible confounding factor that may have influenced HDL-c levels was the practice of physical exercise by vegetarians. Conclusion The findings of this study indicated that, compared with omnivores, vegetarians have better nutritional status, with lower BMI and WC. Vegetarians were also more likely to practice exercise and showed significantly lower levels of HDL-c. Author contributions Conception and design of the research: Pimentel CVMB, Philippi ST, Teodorov E. Acquisition of data: Pimentel CVMB, Simomura VL. Analysis and interpretation of the data: Pimentel CVMB, Philippi ST, Simomura VL, Teodorov E. Statistical analysis: Pimentel CVMB, Simomura VL. Obtaining financing: Pimentel CVMB, Teodorov E. Writing of the manuscript: Pimentel CVMB. Critical revision of the manuscript for intellectual